From 1b810f5af0682924c75cd2bdfb031047b57dd4db Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Mon, 3 Aug 2026 10:21:14 +1000
Subject: [PATCH 01/17] support single tenant mode with Clickhouse backend

---
 .gitignore                                    |   1 +
 .single_tenant_ch.env                         |  19 ++
 DEVELOPMENT.md                                |  39 +++-
 Makefile                                      |  17 +-
 config/runtime.exs                            |  40 +++-
 lib/logflare/application.ex                   |   6 +-
 lib/logflare/backends.ex                      | 203 ++++++++++++------
 .../backends/adaptor/clickhouse_adaptor.ex    |  13 +-
 .../clickhouse_adaptor/circuit_breaker.ex     |  10 +-
 .../clickhouse_adaptor/connection_manager.ex  |  10 +-
 .../adaptor/clickhouse_adaptor/pipeline.ex    |  23 +-
 .../query_connection_sup.ex                   |  28 +--
 lib/logflare/backends/backend.ex              |   1 +
 lib/logflare/backends/buffer_producer.ex      |   6 +-
 lib/logflare/backends/consolidated_sup.ex     |   4 +-
 .../backends/consolidated_sup_worker.ex       |  16 +-
 lib/logflare/backends/ingest_event_queue.ex   |   4 +-
 .../ingest_event_queue/queue_janitor.ex       |   2 +-
 lib/logflare/backends/source_sup.ex           |   4 +-
 lib/logflare/networking.ex                    |  12 +-
 lib/logflare/pubsub_rates/cache.ex            |   9 +-
 lib/logflare/single_tenant.ex                 | 123 +++++++++--
 lib/logflare/sources.ex                       |  30 ++-
 .../sources/source/rate_counter_server.ex     |   3 +-
 lib/logflare/sources/source/supervisor.ex     |  22 +-
 .../single_tenant_ingestion_test.exs          |  99 +++++++++
 .../adaptor/clickhouse_adaptor_test.exs       |  13 ++
 test/logflare/backends/backend_test.exs       |  16 ++
 .../backends/consolidated_sup_worker_test.exs |  23 ++
 .../backends/ingest_event_queue_test.exs      |  10 +-
 .../backends/spool/memory_monitor_test.exs    |   6 +-
 test/logflare/backends_test.exs               |  72 ++++++-
 test/logflare/networking_test.exs             |  45 +++-
 test/logflare/single_tenant_test.exs          | 107 ++++++++-
 test/logflare/sources_test.exs                |  96 +++++++++
 .../controllers/plugs/buffer_limiter_test.exs |  38 +++-
 test/support/test_utils.ex                    |  41 +++-
 37 files changed, 1001 insertions(+), 210 deletions(-)
 create mode 100644 .single_tenant_ch.env
 create mode 100644 test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs

diff --git a/.gitignore b/.gitignore
index d734441c96..a401d7ab88 100644
--- a/.gitignore
+++ b/.gitignore
@@ -63,6 +63,7 @@ gha-creds-*.json
 
 !.template.env
 !.single_tenant_bq.env
+!.single_tenant_ch.env
 !.single_tenant_pg.env
 # rustler nif binaries
 /priv/native
diff --git a/.single_tenant_ch.env b/.single_tenant_ch.env
new file mode 100644
index 0000000000..6bdec1ec33
--- /dev/null
+++ b/.single_tenant_ch.env
@@ -0,0 +1,19 @@
+PHX_HTTP_PORT=4000
+DB_DATABASE=logflare_dev
+DB_HOSTNAME=localhost
+DB_PORT=5432
+DB_PASSWORD=postgres
+DB_USERNAME=postgres
+DB_SCHEMA=public
+
+LOGFLARE_SINGLE_TENANT=true
+LOGFLARE_PRIVATE_ACCESS_TOKEN=my-cool-api-key-123
+LOGFLARE_PUBLIC_ACCESS_TOKEN=my-other-cool-api-key-123
+LOGFLARE_GRPC_PORT=50051
+
+CLICKHOUSE_BACKEND_URL=http://logflare:logflare@localhost:8123/logflare_test
+CLICKHOUSE_BACKEND_POOL_SIZE=3
+
+LOGFLARE_NODE_HOST=127.0.0.1
+LOGFLARE_HTTP_CONNECTION_POOLS=all
+LOGFLARE_FEATURE_FLAG_OVERRIDE=multibackend=true,key_values=true
diff --git a/DEVELOPMENT.md b/DEVELOPMENT.md
index 4e319ad376..e800bad3e6 100644
--- a/DEVELOPMENT.md
+++ b/DEVELOPMENT.md
@@ -53,7 +53,7 @@ docker-compose up -d db clickhouse telegraf
 # install dependencies
 make setup
 
-# start in single tenant postgres backend (logflare_dev)
+# start in single tenant postgres backend (logflare_dev). See [Developing for Single Tenant](#developing-for-single-tenant) for other backends.
 make start.st.pg
 
 # run tests
@@ -73,17 +73,49 @@ To configure the BigQuery backend, please follow the [BigQuery setup documentati
 
 ### Developing for Single Tenant
 
-Use the single tenant `make start.*` variations. This works by switching out the `LOGFLARE_SINGLE_TENANT` env var.
+Use a backend-specific single tenant target. Each target loads its corresponding
+`.single_tenant_*.env` file and enables `LOGFLARE_SINGLE_TENANT`.
 
 ```bash
 make start.st.pg
 make start.st.bq
+make start.st.ch
 ```
 
+#### ClickHouse
+
+Start the application PostgreSQL database and ClickHouse service, then start Logflare:
+
+```bash
+docker compose up -d db clickhouse telegraf
+make start.st.ch
+```
+
+`make start.st.ch` loads `.single_tenant_ch.env`. The main settings are:
+
+- `CLICKHOUSE_BACKEND_URL` - the ClickHouse HTTP connection URL, including the database name
+- `CLICKHOUSE_BACKEND_POOL_SIZE` - optional connection pool size
+- `LOGFLARE_PUBLIC_ACCESS_TOKEN` and `LOGFLARE_PRIVATE_ACCESS_TOKEN` - local API tokens
+
+PostgreSQL is still required for Logflare application data. ClickHouse becomes the default
+log backend and uses one shared ingestion pipeline configured from `CLICKHOUSE_BACKEND_URL`; the
+default ClickHouse backend is not stored as a database record.
+
+The local URL is typically:
+
+```text
+http://logflare:logflare@localhost:8123/logflare_test
+```
+
+If both `POSTGRES_BACKEND_URL` and `CLICKHOUSE_BACKEND_URL` are present in the effective
+environment, PostgreSQL takes precedence. Unset `POSTGRES_BACKEND_URL` when using
+`make start.st.ch`.
+
 To develop with Supabase mode:
 
 ```bash
 make start.sb.bq
+make start.sb.ch
 make start.sb.pg
 ```
 
@@ -164,7 +196,8 @@ bin/compose down -v
 make setup
 make start
 make start.{orange|pink}
-make start.{st|sb}.{bq|pg}
+make start.st.{bq|ch|pg}
+make start.sb.{bq|ch|pg}
 make decrypt.{dev|staging|prod}
 make encrypt.{dev|staging|prod}
 make reset
diff --git a/Makefile b/Makefile
index 8c39f67cb3..ccd67dc298 100644
--- a/Makefile
+++ b/Makefile
@@ -120,7 +120,7 @@ setup: check-tools check-version-manager setup.node
 setup.node:
 	@echo -e "$(BOLD)$(BLUE)📦 Installing Node.js dependencies...$(NC)"
 	@echo ""
-	npm --prefix ./assets ci 
+	npm --prefix ./assets ci
 	@echo ""
 
 reset:
@@ -157,6 +157,9 @@ start.green: __start__
 start.sb.bq: LOGFLARE_SUPABASE_MODE = true
 start.sb.bq: start.st.bq
 
+start.sb.ch: LOGFLARE_SUPABASE_MODE = true
+start.sb.ch: start.st.ch
+
 # SPOOL_MODE (producer|consumer|both), SPOOL_PROVIDER (aws|gcp), and related
 # SPOOL_* vars pass straight through to the app via __start__ (see config/runtime.exs).
 # To run a producer + consumer pair side by side, override PORT/ERL_NAME/LOGFLARE_GRPC_PORT
@@ -169,6 +172,12 @@ start.st.bq: ENV_FILE = .single_tenant_bq.env
 start.st.bq: LOGFLARE_GRPC_PORT ?= 50051
 start.st.bq: __start__
 
+start.st.ch: ERL_NAME ?= st_
+start.st.ch: PORT ?= 4000
+start.st.ch: ENV_FILE = .single_tenant_ch.env
+start.st.ch: LOGFLARE_GRPC_PORT ?= 50051
+start.st.ch: __start__
+
 start.sb.pg: LOGFLARE_SUPABASE_MODE = true
 start.sb.pg: start.st.pg
 
@@ -195,7 +204,7 @@ migrate:
 stripe:
 	stripe listen --forward-to localhost:4000/webhooks/stripe
 
-.PHONY: __start__ migrate stripe start.sb.pg start.sb.bq start.st.pg start.st.bq start.orange start.pink
+.PHONY: __start__ migrate stripe start.sb.pg start.sb.ch start.sb.bq start.st.pg start.st.ch start.st.bq start.orange start.pink
 
 # Encryption and decryption of secrets
 # Usage:
@@ -463,12 +472,12 @@ $(TELEGRAF_KEYS_SENTINEL):
 
 	# Server (Telegraf)
 	@echo "subjectAltName=DNS:localhost,IP:127.0.0.1,DNS:telegraf" > $(TELEGRAF_KEYS_DIR)/server.ext
-	
+
 	@openssl genrsa -out $(TELEGRAF_KEYS_DIR)/server.key 2048
 	@openssl req -new -key $(TELEGRAF_KEYS_DIR)/server.key \
 		-subj "/CN=localhost" \
 		-out $(TELEGRAF_KEYS_DIR)/server.csr
-	
+
 	@openssl x509 -req -days 3650 -in $(TELEGRAF_KEYS_DIR)/server.csr \
 		-CA $(TELEGRAF_KEYS_DIR)/ca.crt -CAkey $(TELEGRAF_KEYS_DIR)/ca.key -set_serial 01 \
 		-out $(TELEGRAF_KEYS_DIR)/server.crt \
diff --git a/config/runtime.exs b/config/runtime.exs
index f83af81b74..acfe3090dc 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -1,5 +1,6 @@
 import Config
 
+alias Logflare.SingleTenant
 alias Logflare.Utils
 
 defmodule Env do
@@ -390,15 +391,46 @@ socket_options_for_url = fn
     nil
 end
 
+single_tenant? = Env.get_boolean("LOGFLARE_SINGLE_TENANT")
+postgres_backend_url = System.get_env("POSTGRES_BACKEND_URL")
+clickhouse_backend_url = System.get_env("CLICKHOUSE_BACKEND_URL")
+
+backend_url_set? = fn url -> is_binary(url) and String.trim(url) != "" end
+
+single_tenant_backend =
+  cond do
+    single_tenant? and backend_url_set?.(postgres_backend_url) -> :postgres
+    single_tenant? and backend_url_set?.(clickhouse_backend_url) -> :clickhouse
+    true -> :bigquery
+  end
+
+config :logflare, :single_tenant_backend, single_tenant_backend
+
 cond do
-  Env.get_boolean("LOGFLARE_SINGLE_TENANT") &&
-      not is_nil(System.get_env("POSTGRES_BACKEND_URL")) ->
+  single_tenant? and single_tenant_backend == :postgres ->
     config :logflare,
            :postgres_backend_adapter,
            filter_nil_kv_pairs.(
-             url: System.get_env("POSTGRES_BACKEND_URL"),
+             url: postgres_backend_url,
              schema: System.get_env("POSTGRES_BACKEND_SCHEMA"),
-             socket_options: socket_options_for_url.(System.get_env("POSTGRES_BACKEND_URL", ""))
+             socket_options: socket_options_for_url.(postgres_backend_url)
+           )
+
+  single_tenant? and single_tenant_backend == :clickhouse ->
+    clickhouse_backend_config =
+      SingleTenant.clickhouse_backend_adapter_opts_from_url!(clickhouse_backend_url)
+
+    config :logflare,
+           :clickhouse_backend_adapter,
+           filter_nil_kv_pairs.(
+             clickhouse_backend_config ++
+               [
+                 pool_size:
+                   case System.get_env("CLICKHOUSE_BACKEND_POOL_SIZE") do
+                     nil -> nil
+                     value -> String.to_integer(value)
+                   end
+               ]
            )
 
   config_env() != :test ->
diff --git a/lib/logflare/application.ex b/lib/logflare/application.ex
index 51ced4df32..a08ee5acf2 100644
--- a/lib/logflare/application.ex
+++ b/lib/logflare/application.ex
@@ -5,6 +5,7 @@ defmodule Logflare.Application do
   require Logger
 
   alias Logflare.Alerting.AlertSchedulerWorker
+  alias Logflare.Backends
   alias Logflare.Networking
   alias Logflare.Backends.Adaptor.BigQueryAdaptor
   alias Logflare.Backends.Spool.Health, as: SpoolHealth
@@ -234,7 +235,7 @@ defmodule Logflare.Application do
   def startup_tasks do
     Logger.info("Executing startup tasks")
 
-    if !SingleTenant.postgres_backend?() do
+    if Backends.bigquery_default_backend?() do
       BigQueryAdaptor.create_managed_service_accounts()
       BigQueryAdaptor.update_iam_policy()
     end
@@ -243,6 +244,7 @@ defmodule Logflare.Application do
       Logger.info("Ensuring single tenant user is seeded...")
       SingleTenant.create_default_plan()
       SingleTenant.create_default_user()
+      SingleTenant.ensure_default_backend()
       SingleTenant.create_access_tokens()
     end
 
@@ -251,7 +253,7 @@ defmodule Logflare.Application do
       SingleTenant.create_supabase_endpoints()
       SingleTenant.ensure_supabase_sources_started()
 
-      unless SingleTenant.postgres_backend?() do
+      if Backends.bigquery_default_backend?() do
         # buffer time for all sources to init and create tables
         # in case of latency.
         :timer.sleep(3_000)
diff --git a/lib/logflare/backends.ex b/lib/logflare/backends.ex
index 96e8a7467b..ab8586a852 100644
--- a/lib/logflare/backends.ex
+++ b/lib/logflare/backends.ex
@@ -42,8 +42,12 @@ defmodule Logflare.Backends do
   @max_pending_buffer_len_per_queue IngestEventQueue.max_queue_size()
   @default_source_sup_start_timeout :timer.seconds(30)
   @max_pipeline_swap_delay_ms 5_000
+  @single_tenant_clickhouse_backend_id 0
 
   @type one_or_list_or_nil :: Backend.t() | [Backend.t()] | nil
+  @type ingest_queue_key ::
+          IngestEventQueue.queues_key() | IngestEventQueue.consolidated_queues_key()
+  @type queue_owner :: non_neg_integer() | :consolidated
 
   @doc """
   Retrieves the hardcoded max pending buffer length of an individual queue
@@ -51,6 +55,29 @@ defmodule Logflare.Backends do
   @spec max_buffer_queue_len() :: non_neg_integer()
   def max_buffer_queue_len, do: @max_pending_buffer_len_per_queue
 
+  @doc "Returns whether BigQuery is the deployment's default backend"
+  @spec bigquery_default_backend?() :: boolean()
+  def bigquery_default_backend?,
+    do: not SingleTenant.single_tenant?() or SingleTenant.bigquery_backend?()
+
+  @doc false
+  @spec ingest_queue_key(Source.t(), Backend.t() | nil) :: ingest_queue_key()
+  def ingest_queue_key(%Source{}, %Backend{consolidated_ingest?: true, id: backend_id}) do
+    {:consolidated, backend_id}
+  end
+
+  def ingest_queue_key(%Source{id: source_id}, %Backend{id: backend_id}) do
+    {source_id, backend_id}
+  end
+
+  def ingest_queue_key(%Source{id: source_id}, nil), do: {source_id, nil}
+
+  @doc false
+  @spec system_default_ingest_queue_key(Source.t()) :: ingest_queue_key()
+  def system_default_ingest_queue_key(%Source{} = source) do
+    ingest_queue_key(source, lookup_system_default_backend(source))
+  end
+
   @doc """
   Returns the maximum time, in microseconds, that an event's timestamp may be in
   the future and still be accepted at ingestion. Events further ahead than this
@@ -244,29 +271,53 @@ defmodule Logflare.Backends do
     end
   end
 
+  @spec get_single_tenant_default_backend() :: Backend.t() | nil
+  def get_single_tenant_default_backend do
+    user = SingleTenant.get_default_user()
+
+    if SingleTenant.clickhouse_backend?() && user,
+      do: single_tenant_clickhouse_backend(user)
+  end
+
+  defp single_tenant_clickhouse_backend(%User{} = user) do
+    %Backend{
+      id: @single_tenant_clickhouse_backend_id,
+      token: "00000000-0000-0000-0000-000000000000",
+      type: :clickhouse,
+      config: Map.new(SingleTenant.clickhouse_backend_adapter_opts()),
+      user_id: user.id,
+      name: "Default ClickHouse backend",
+      consolidated_ingest?: true,
+      single_tenant_default?: true
+    }
+  end
+
+  @spec get_default_backend(User.t()) :: Backend.t() | nil
   def get_default_backend(%User{} = user) do
-    if SingleTenant.single_tenant?() and SingleTenant.postgres_backend?() do
-      opts = SingleTenant.postgres_backend_adapter_opts()
-
-      %Backend{
-        type: :postgres,
-        config: Map.new(opts),
-        user_id: user.id,
-        name: "Default PostgreSQL backend"
-      }
-    else
-      project_id = user.bigquery_project_id || User.bq_project_id()
-      dataset_id = user.bigquery_dataset_id || User.generate_bq_dataset_id(user.id)
-
-      %Backend{
-        type: :bigquery,
-        config: %{
-          project_id: project_id,
-          dataset_id: dataset_id
-        },
-        user_id: user.id,
-        name: "Default BigQuery backend"
-      }
+    cond do
+      SingleTenant.clickhouse_backend?() ->
+        single_tenant_clickhouse_backend(user)
+
+      SingleTenant.postgres_backend?() ->
+        opts = SingleTenant.postgres_backend_adapter_opts()
+
+        %Backend{
+          type: :postgres,
+          config: Map.new(opts),
+          user_id: user.id,
+          name: "Default PostgreSQL backend"
+        }
+
+      true ->
+        project_id = user.bigquery_project_id || User.bq_project_id()
+        dataset_id = user.bigquery_dataset_id || User.generate_bq_dataset_id(user.id)
+
+        %Backend{
+          type: :bigquery,
+          config: %{project_id: project_id, dataset_id: dataset_id},
+          user_id: user.id,
+          name: "Default BigQuery backend"
+        }
     end
   end
 
@@ -536,6 +587,8 @@ defmodule Logflare.Backends do
   Retrieves a Backend by id.
   """
   @spec get_backend(integer()) :: Backend.t() | nil
+  def get_backend(@single_tenant_clickhouse_backend_id), do: get_single_tenant_default_backend()
+
   def get_backend(id) do
     backend = Repo.get(Backend, id)
 
@@ -989,28 +1042,25 @@ defmodule Logflare.Backends do
   defp dispatch_to_backends(source, nil, log_events) do
     backends = __MODULE__.Cache.list_backends(source_id: source.id)
 
-    for backend <- [nil | backends] do
+    for backend <- [lookup_system_default_backend(source) | backends] do
       dispatch_to_default_backend(source, backend, log_events)
     end
   end
 
+  defp lookup_system_default_backend(%Source{user_id: user_id}) do
+    if SingleTenant.clickhouse_backend?() do
+      get_default_backend(%User{id: user_id})
+    end
+  end
+
   @spec dispatch_to_default_backend(
           source :: Source.t(),
           backend :: Backend.t() | nil,
           log_events :: [LogEvent.t()]
         ) :: any()
   defp dispatch_to_default_backend(source, backend, log_events) do
-    {queue_key, backend_type} =
-      case backend do
-        nil ->
-          {{source.id, nil}, SingleTenant.backend_type()}
-
-        %Backend{consolidated_ingest?: true} ->
-          {{:consolidated, backend.id}, backend.type}
-
-        %Backend{} ->
-          {{source.id, backend.id}, backend.type}
-      end
+    queue_key = ingest_queue_key(source, backend)
+    backend_type = if backend, do: backend.type, else: SingleTenant.backend_type()
 
     telemetry_metadata = %{backend_type: backend_type}
 
@@ -1085,7 +1135,7 @@ defmodule Logflare.Backends do
 
   def via_backend(backend_id, mod, nil), do: via_backend(backend_id, mod)
 
-  def via_backend(backend_id, mod, label) when is_pos_integer(backend_id) do
+  def via_backend(backend_id, mod, label) when is_non_negative_integer(backend_id) do
     {:via, Registry, {BackendRegistry, {mod, backend_id, label}}}
   end
 
@@ -1401,35 +1451,32 @@ defmodule Logflare.Backends do
     - Returns true only if ALL queues are full
   """
   @spec cached_local_pending_buffer_full?(Source.t()) :: boolean()
-  def cached_local_pending_buffer_full?(%Source{
-        id: source_id,
-        default_ingest_backend_enabled?: true
-      }) do
-    default_backend_ids =
-      __MODULE__.Cache.list_backends(source_id: source_id)
+  def cached_local_pending_buffer_full?(
+        %Source{
+          default_ingest_backend_enabled?: true
+        } = source
+      ) do
+    default_backend_queue_keys =
+      __MODULE__.Cache.list_backends(source_id: source.id)
       |> Enum.filter(& &1.default_ingest?)
-      |> MapSet.new(& &1.id)
+      |> MapSet.new(&ingest_queue_key(source, &1))
 
-    # Check system default backend (nil backend_id)
-    system_default_full? = buffer_full_for_backend?(source_id, nil)
+    system_default_full? = buffer_full_for_queue?(system_default_ingest_queue_key(source))
 
-    # Check user-configured default backends
-    user_defaults_full? = Enum.any?(default_backend_ids, &buffer_full_for_backend?(source_id, &1))
+    user_defaults_full? = Enum.any?(default_backend_queue_keys, &buffer_full_for_queue?/1)
 
     system_default_full? || user_defaults_full?
   end
 
-  def cached_local_pending_buffer_full?(%Source{id: source_id}) do
-    buffer_full_for_backend?(source_id, nil)
+  def cached_local_pending_buffer_full?(%Source{} = source) do
+    source
+    |> system_default_ingest_queue_key()
+    |> buffer_full_for_queue?()
   end
 
-  @spec buffer_full_for_backend?(
-          source_id :: non_neg_integer(),
-          backend_id :: non_neg_integer() | nil
-        ) ::
-          boolean()
-  defp buffer_full_for_backend?(source_id, backend_id) do
-    case PubSubRates.Cache.get_local_buffer(source_id, backend_id) do
+  @spec buffer_full_for_queue?(ingest_queue_key()) :: boolean()
+  defp buffer_full_for_queue?({queue_owner, backend_id}) do
+    case PubSubRates.Cache.get_local_buffer(queue_owner, backend_id) do
       %{queues: [_ | _] = queues} ->
         Enum.all?(queues, fn {_key, count} ->
           count > @max_pending_buffer_len_per_queue
@@ -1453,14 +1500,26 @@ defmodule Logflare.Backends do
   """
   @spec any_ingest_queue_over_limit?(pos_integer()) :: boolean()
   def any_ingest_queue_over_limit?(source_id) do
-    backend_ids =
-      [nil | __MODULE__.Cache.list_backends(source_id: source_id) |> Enum.map(& &1.id)]
+    source = Sources.Cache.get_by_id(source_id)
+
+    queue_keys =
+      case source do
+        %Source{} ->
+          backend_queue_keys =
+            __MODULE__.Cache.list_backends(source_id: source_id)
+            |> Enum.map(&ingest_queue_key(source, &1))
+
+          [system_default_ingest_queue_key(source) | backend_queue_keys]
 
-    Enum.any?(backend_ids, &any_queue_over_limit_for_backend?(source_id, &1))
+        nil ->
+          if SingleTenant.clickhouse_backend?(), do: [], else: [{source_id, nil}]
+      end
+
+    Enum.any?(queue_keys, &any_queue_over_limit?/1)
   end
 
-  defp any_queue_over_limit_for_backend?(source_id, backend_id) do
-    {source_id, backend_id}
+  defp any_queue_over_limit?(queue_key) do
+    queue_key
     |> IngestEventQueue.list_queues()
     |> Enum.any?(&queue_over_limit?/1)
   end
@@ -1475,29 +1534,30 @@ defmodule Logflare.Backends do
   @doc """
   Caches total buffer len. Includes ingested events that are awaiting cleanup.
   """
-  @spec cache_local_buffer_lens(non_neg_integer(), non_neg_integer() | nil) ::
+  @spec cache_local_buffer_lens(queue_owner(), non_neg_integer() | nil) ::
           {:ok,
            %{
              len: non_neg_integer(),
-             queues: [{Logflare.Backends.IngestEventQueue.table_key(), non_neg_integer()}]
+             queues: [{tuple(), non_neg_integer()}]
            }}
-  def cache_local_buffer_lens(source_id, backend_id \\ nil) do
-    queues = IngestEventQueue.list_counts({source_id, backend_id})
+  def cache_local_buffer_lens(queue_owner, backend_id \\ nil) do
+    queues = IngestEventQueue.list_counts({queue_owner, backend_id})
 
     len = for({_k, v} <- queues, do: v) |> Enum.sum()
 
     stats = %{len: len, queues: queues}
     payload = %{Node.self() => stats}
-    PubSubRates.Cache.cache_buffers(source_id, backend_id, payload)
+    PubSubRates.Cache.cache_buffers(queue_owner, backend_id, payload)
     {:ok, stats}
   end
 
   @doc """
   Get local pending buffer len of a source/backend combination.
   """
-  @spec cached_local_pending_buffer_len(Source.t(), Backend.t() | nil) :: map()
-  def cached_local_pending_buffer_len(source_id, backend_id \\ nil) when is_integer(source_id) do
-    PubSubRates.Cache.get_local_buffer(source_id, backend_id)
+  @spec cached_local_pending_buffer_len(queue_owner(), non_neg_integer() | nil) :: map()
+  def cached_local_pending_buffer_len(queue_owner, backend_id \\ nil)
+      when is_integer(queue_owner) or queue_owner == :consolidated do
+    PubSubRates.Cache.get_local_buffer(queue_owner, backend_id)
   end
 
   @doc """
@@ -1505,7 +1565,12 @@ defmodule Logflare.Backends do
   """
   @spec cached_pending_buffer_len(Source.t(), Backend.t() | nil) :: non_neg_integer()
   def cached_pending_buffer_len(%Source{} = source, backend \\ nil) do
-    PubSubRates.Cache.get_cluster_buffers(source.id, Map.get(backend || %{}, :id))
+    {queue_owner, backend_id} =
+      if backend,
+        do: ingest_queue_key(source, backend),
+        else: system_default_ingest_queue_key(source)
+
+    PubSubRates.Cache.get_cluster_buffers(queue_owner, backend_id)
   end
 
   @doc """
diff --git a/lib/logflare/backends/adaptor/clickhouse_adaptor.ex b/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
index 44a51449cc..5f6d484efb 100644
--- a/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
+++ b/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
@@ -706,8 +706,19 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor do
   - `:log`    -> `otel_logs_<token>`
   - `:metric` -> `otel_metrics_<token>`
   - `:trace`  -> `otel_traces_<token>`
+
+  Single-tenant defaults use `single_tenant` suffix in place of `<token>`
   """
   @spec clickhouse_ingest_table_name(Backend.t(), TypeDetection.event_type()) :: String.t()
+  def clickhouse_ingest_table_name(%Backend{single_tenant_default?: true}, :log),
+    do: "otel_logs_single_tenant"
+
+  def clickhouse_ingest_table_name(%Backend{single_tenant_default?: true}, :metric),
+    do: "otel_metrics_single_tenant"
+
+  def clickhouse_ingest_table_name(%Backend{single_tenant_default?: true}, :trace),
+    do: "otel_traces_single_tenant"
+
   def clickhouse_ingest_table_name(%Backend{} = backend, :log),
     do: build_otel_table_name(backend, "otel_logs")
 
@@ -1608,7 +1619,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor do
     end
   end
 
-  @spec maybe_start_query_connection_manager(pid() | nil, pos_integer(), String.t() | nil) ::
+  @spec maybe_start_query_connection_manager(pid() | nil, non_neg_integer(), String.t() | nil) ::
           :ok | {:error, term()}
   defp maybe_start_query_connection_manager(nil, backend_id, label)
        when is_pos_integer(backend_id) do
diff --git a/lib/logflare/backends/adaptor/clickhouse_adaptor/circuit_breaker.ex b/lib/logflare/backends/adaptor/clickhouse_adaptor/circuit_breaker.ex
index 9fbeaf8df7..b04c64a7bc 100644
--- a/lib/logflare/backends/adaptor/clickhouse_adaptor/circuit_breaker.ex
+++ b/lib/logflare/backends/adaptor/clickhouse_adaptor/circuit_breaker.ex
@@ -26,7 +26,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.CircuitBreaker do
   @block_ms :timer.seconds(30)
 
   typedstruct do
-    field :backend_id, pos_integer(), enforce: true
+    field :backend_id, non_neg_integer(), enforce: true
     field :table, :ets.table(), enforce: true
     field :failures, [integer()], default: []
   end
@@ -52,10 +52,10 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.CircuitBreaker do
   Reads the breaker's ETS table directly via the backend registry, so a missing
   or crashed breaker reads as allowed.
   """
-  @spec check(Backend.t() | pos_integer()) :: :ok | {:error, :circuit_open, integer()}
+  @spec check(Backend.t() | non_neg_integer()) :: :ok | {:error, :circuit_open, integer()}
   def check(%Backend{id: backend_id}), do: check(backend_id)
 
-  def check(backend_id) when is_pos_integer(backend_id) do
+  def check(backend_id) when is_non_negative_integer(backend_id) do
     with [{_pid, table}] when not is_nil(table) <-
            Registry.lookup(BackendRegistry, {__MODULE__, backend_id}),
          [{@blocked_key, blocked_until}] <- safe_lookup(table, @blocked_key),
@@ -112,10 +112,10 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.CircuitBreaker do
 
   Useful for introspection (_and tests_).
   """
-  @spec get_state(Backend.t() | pos_integer()) :: t() | nil
+  @spec get_state(Backend.t() | non_neg_integer()) :: t() | nil
   def get_state(%Backend{id: backend_id}), do: get_state(backend_id)
 
-  def get_state(backend_id) when is_pos_integer(backend_id) do
+  def get_state(backend_id) when is_non_negative_integer(backend_id) do
     case Registry.lookup(BackendRegistry, {__MODULE__, backend_id}) do
       [{pid, _table}] -> GenServer.call(pid, :get_state)
       [] -> nil
diff --git a/lib/logflare/backends/adaptor/clickhouse_adaptor/connection_manager.ex b/lib/logflare/backends/adaptor/clickhouse_adaptor/connection_manager.ex
index 0676b52eb5..d37bf86299 100644
--- a/lib/logflare/backends/adaptor/clickhouse_adaptor/connection_manager.ex
+++ b/lib/logflare/backends/adaptor/clickhouse_adaptor/connection_manager.ex
@@ -46,7 +46,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.ConnectionManager do
   @telemetry_listener __MODULE__.TelemetryListener
 
   typedstruct do
-    field :backend_id, pos_integer(), enforce: true
+    field :backend_id, non_neg_integer(), enforce: true
     field :label, String.t() | nil, default: nil
     field :pool_pid, pid() | nil, default: nil
     field :last_activity, integer() | nil, default: nil
@@ -573,7 +573,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.ConnectionManager do
     urls = Map.get(config, :read_only_urls) || %{}
     default = Map.get(config, :default_read_cluster)
 
-    labeled_url(urls, label) || labeled_url(urls, default) || Map.get(config, :url)
+    labeled_url(urls, label) || labeled_url(urls, default) || legacy_read_url(config)
   end
 
   @spec labeled_url(map(), String.t() | nil) :: String.t() | nil
@@ -586,6 +586,12 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.ConnectionManager do
 
   defp labeled_url(_urls, _label), do: nil
 
+  @spec legacy_read_url(map()) :: String.t() | nil
+  defp legacy_read_url(config) do
+    read_only_url = Map.get(config, :read_only_url)
+    if is_non_empty_binary(read_only_url), do: read_only_url, else: Map.get(config, :url)
+  end
+
   @spec connection_host(pos_integer(), String.t() | nil) :: String.t() | nil
   defp connection_host(backend_id, label) do
     backend_id
diff --git a/lib/logflare/backends/adaptor/clickhouse_adaptor/pipeline.ex b/lib/logflare/backends/adaptor/clickhouse_adaptor/pipeline.ex
index 51a7005a79..a7a093cf47 100644
--- a/lib/logflare/backends/adaptor/clickhouse_adaptor/pipeline.ex
+++ b/lib/logflare/backends/adaptor/clickhouse_adaptor/pipeline.ex
@@ -531,7 +531,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.Pipeline do
     end
   end
 
-  @spec maybe_requeue_failed(backend_id :: pos_integer(), messages :: [Message.t()]) :: :ok
+  @spec maybe_requeue_failed(backend_id :: non_neg_integer(), messages :: [Message.t()]) :: :ok
   defp maybe_requeue_failed(backend_id, messages) do
     payloads = Enum.map(messages, & &1.data)
 
@@ -544,7 +544,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.Pipeline do
   end
 
   @spec requeue_or_shed(
-          backend_id :: pos_integer(),
+          backend_id :: non_neg_integer(),
           retriable :: [EncodedRow.t() | LogEventPointer.t()]
         ) :: :ok
   defp requeue_or_shed(_backend_id, []), do: :ok
@@ -564,7 +564,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.Pipeline do
   @typep drop_reason :: :retries_exhausted | :circuit_breaker_open
 
   @spec requeue_retriable(
-          backend_id :: pos_integer(),
+          backend_id :: non_neg_integer(),
           retriable :: [EncodedRow.t() | LogEventPointer.t()]
         ) :: :ok
   defp requeue_retriable(backend_id, retriable) do
@@ -590,7 +590,8 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.Pipeline do
     :ok
   end
 
-  @spec requeue_payload(pos_integer(), EncodedRow.t() | LogEventPointer.t()) :: requeue_result()
+  @spec requeue_payload(non_neg_integer(), EncodedRow.t() | LogEventPointer.t()) ::
+          requeue_result()
   defp requeue_payload(backend_id, %EncodedRow{pointer: pointer} = encoded) do
     transfer_retry_payload(backend_id, pointer, encoded)
   end
@@ -602,7 +603,11 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.Pipeline do
     end
   end
 
-  @spec transfer_retry_payload(pos_integer(), LogEventPointer.t(), EncodedRow.t() | LogEvent.t()) ::
+  @spec transfer_retry_payload(
+          non_neg_integer(),
+          LogEventPointer.t(),
+          EncodedRow.t() | LogEvent.t()
+        ) ::
           requeue_result()
   defp transfer_retry_payload(backend_id, pointer, payload) do
     pointer = %{pointer | retries: pointer.retries + 1}
@@ -624,7 +629,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.Pipeline do
   defp requeue_transfer_result({:error, :already_exists}), do: :deduplicated
   defp requeue_transfer_result({:error, :not_initialized}), do: :queue_unavailable
 
-  @spec emit_requeue_deduplicated_telemetry(pos_integer(), non_neg_integer()) :: :ok
+  @spec emit_requeue_deduplicated_telemetry(non_neg_integer(), non_neg_integer()) :: :ok
   defp emit_requeue_deduplicated_telemetry(_backend_id, 0), do: :ok
 
   defp emit_requeue_deduplicated_telemetry(backend_id, deduplicated_count) do
@@ -643,7 +648,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.Pipeline do
   # A lookup miss means GenerationJanitor dropped the backing generation before the
   # retry could resolve its event. Bounded and rare in practice, but worth
   # surfacing since it's otherwise invisible.
-  @spec emit_requeue_lookup_miss_telemetry(pos_integer(), non_neg_integer()) :: :ok
+  @spec emit_requeue_lookup_miss_telemetry(non_neg_integer(), non_neg_integer()) :: :ok
   defp emit_requeue_lookup_miss_telemetry(_backend_id, 0), do: :ok
 
   defp emit_requeue_lookup_miss_telemetry(backend_id, missing_count) do
@@ -659,7 +664,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.Pipeline do
     )
   end
 
-  @spec emit_requeue_queue_unavailable_telemetry(pos_integer(), non_neg_integer()) :: :ok
+  @spec emit_requeue_queue_unavailable_telemetry(non_neg_integer(), non_neg_integer()) :: :ok
   defp emit_requeue_queue_unavailable_telemetry(_backend_id, 0), do: :ok
 
   defp emit_requeue_queue_unavailable_telemetry(backend_id, dropped_count) do
@@ -677,7 +682,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.Pipeline do
 
   @spec drop_failed(
           payloads :: [EncodedRow.t() | LogEventPointer.t()],
-          backend_id :: pos_integer(),
+          backend_id :: non_neg_integer(),
           reason :: drop_reason()
         ) :: :ok
   defp drop_failed([], _backend_id, _reason), do: :ok
diff --git a/lib/logflare/backends/adaptor/clickhouse_adaptor/query_connection_sup.ex b/lib/logflare/backends/adaptor/clickhouse_adaptor/query_connection_sup.ex
index f8c0c5fbf4..12c3f2e830 100644
--- a/lib/logflare/backends/adaptor/clickhouse_adaptor/query_connection_sup.ex
+++ b/lib/logflare/backends/adaptor/clickhouse_adaptor/query_connection_sup.ex
@@ -156,10 +156,10 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.QueryConnectionSup do
 
   Note that this call does block while waiting to dispatch to all nodes.
   """
-  @spec recycle_backend(Backend.t() | pos_integer()) :: %{node() => :ok | {:error, term()}}
+  @spec recycle_backend(Backend.t() | non_neg_integer()) :: %{node() => :ok | {:error, term()}}
   def recycle_backend(%Backend{id: backend_id}), do: recycle_backend(backend_id)
 
-  def recycle_backend(backend_id) when is_pos_integer(backend_id) do
+  def recycle_backend(backend_id) when is_non_negative_integer(backend_id) do
     Logger.info("Recycling ClickHouse read pool connections across the cluster",
       backend_id: backend_id
     )
@@ -190,8 +190,8 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.QueryConnectionSup do
 
   Invoked on each node by `recycle_backend/1`.
   """
-  @spec recycle_backend_local(pos_integer()) :: :ok | {:error, term()}
-  def recycle_backend_local(backend_id) when is_pos_integer(backend_id) do
+  @spec recycle_backend_local(non_neg_integer()) :: :ok | {:error, term()}
+  def recycle_backend_local(backend_id) when is_non_negative_integer(backend_id) do
     case lookup_managers(backend_id) do
       [] -> {:error, :no_manager}
       manager_pids -> manager_pids |> Enum.map(&safe_recycle/1) |> aggregate_results()
@@ -211,10 +211,10 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.QueryConnectionSup do
 
   Pools restart lazily on demand.
   """
-  @spec refresh_backend(Backend.t() | pos_integer()) :: :ok
+  @spec refresh_backend(Backend.t() | non_neg_integer()) :: :ok
   def refresh_backend(%Backend{id: backend_id}), do: refresh_backend(backend_id)
 
-  def refresh_backend(backend_id) when is_pos_integer(backend_id) do
+  def refresh_backend(backend_id) when is_non_negative_integer(backend_id) do
     Logger.info("Refreshing ClickHouse read pools across the cluster",
       backend_id: backend_id
     )
@@ -228,8 +228,8 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.QueryConnectionSup do
 
   Invoked on each node by `refresh_backend/1`.
   """
-  @spec refresh_backend_local(pos_integer()) :: :ok
-  def refresh_backend_local(backend_id) when is_pos_integer(backend_id) do
+  @spec refresh_backend_local(non_neg_integer()) :: :ok
+  def refresh_backend_local(backend_id) when is_non_negative_integer(backend_id) do
     ContextCache.bust_keys([{Backends, backend_id}])
 
     backend_id
@@ -250,10 +250,10 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.QueryConnectionSup do
   Terminates the read `ConnectionManager` and its pool for a backend on every node
   in the cluster. Used when a backend is deleted. Fire-and-forget.
   """
-  @spec terminate_backend(Backend.t() | pos_integer()) :: :ok
+  @spec terminate_backend(Backend.t() | non_neg_integer()) :: :ok
   def terminate_backend(%Backend{id: backend_id}), do: terminate_backend(backend_id)
 
-  def terminate_backend(backend_id) when is_pos_integer(backend_id) do
+  def terminate_backend(backend_id) when is_non_negative_integer(backend_id) do
     Logger.info("Terminating ClickHouse read connection managers across the cluster",
       backend_id: backend_id
     )
@@ -267,8 +267,8 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.QueryConnectionSup do
 
   Invoked on each node by `terminate_backend/1`.
   """
-  @spec terminate_backend_local(pos_integer()) :: :ok
-  def terminate_backend_local(backend_id) when is_pos_integer(backend_id) do
+  @spec terminate_backend_local(non_neg_integer()) :: :ok
+  def terminate_backend_local(backend_id) when is_non_negative_integer(backend_id) do
     backend_id
     |> lookup_managers()
     |> Enum.each(&terminate_manager/1)
@@ -276,8 +276,8 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.QueryConnectionSup do
     :ok
   end
 
-  @spec lookup_managers(pos_integer()) :: [pid()]
-  defp lookup_managers(backend_id) when is_pos_integer(backend_id) do
+  @spec lookup_managers(non_neg_integer()) :: [pid()]
+  defp lookup_managers(backend_id) when is_non_negative_integer(backend_id) do
     manager = ConnectionManager
 
     ms =
diff --git a/lib/logflare/backends/backend.ex b/lib/logflare/backends/backend.ex
index 6736e39a15..b95d3a0e24 100644
--- a/lib/logflare/backends/backend.ex
+++ b/lib/logflare/backends/backend.ex
@@ -72,6 +72,7 @@ defmodule Logflare.Backends.Backend do
     field :metadata, :map
     field :default_ingest?, :boolean, source: :default_ingest, default: false
     field :enabled, :boolean, default: true
+    field :single_tenant_default?, :boolean, virtual: true, default: false
 
     belongs_to :user, User
 
diff --git a/lib/logflare/backends/buffer_producer.ex b/lib/logflare/backends/buffer_producer.ex
index d0cf3bd89e..132d72d428 100644
--- a/lib/logflare/backends/buffer_producer.ex
+++ b/lib/logflare/backends/buffer_producer.ex
@@ -22,7 +22,7 @@ defmodule Logflare.Backends.BufferProducer do
           demand: non_neg_integer(),
           source_id: pos_integer() | nil,
           source_token: atom() | nil,
-          backend_id: pos_integer(),
+          backend_id: non_neg_integer(),
           last_discard_log_dt: DateTime.t() | nil,
           interval: pos_integer(),
           in_flight_ref: :atomics.atomics_ref() | nil,
@@ -47,7 +47,7 @@ defmodule Logflare.Backends.BufferProducer do
 
   @type state :: standard_state() | spool_producer_state()
 
-  @type table_key :: {pos_integer() | atom(), pos_integer() | nil, pid() | nil}
+  @type table_key :: {pos_integer() | atom(), non_neg_integer() | nil, pid() | nil}
 
   @in_flight_registry Logflare.Backends.BufferProducer.InFlightRegistry
 
@@ -233,7 +233,7 @@ defmodule Logflare.Backends.BufferProducer do
     reschedule(state, false, false)
   end
 
-  @spec init_consolidated_state(pos_integer(), pos_integer(), keyword()) :: state()
+  @spec init_consolidated_state(non_neg_integer(), pos_integer(), keyword()) :: state()
   defp init_consolidated_state(backend_id, interval, opts) do
     id_passing = Keyword.get(opts, :id_passing, false)
     {in_flight_ref, max_in_flight} = init_in_flight(id_passing, Keyword.get(opts, :max_in_flight))
diff --git a/lib/logflare/backends/consolidated_sup.ex b/lib/logflare/backends/consolidated_sup.ex
index 6902ae2571..655bf64913 100644
--- a/lib/logflare/backends/consolidated_sup.ex
+++ b/lib/logflare/backends/consolidated_sup.ex
@@ -57,7 +57,7 @@ defmodule Logflare.Backends.ConsolidatedSup do
   @doc """
   Stops a consolidated pipeline for a backend.
   """
-  @spec stop_pipeline(Backend.t() | pos_integer()) :: :ok | {:error, :not_found}
+  @spec stop_pipeline(Backend.t() | non_neg_integer()) :: :ok | {:error, :not_found}
   def stop_pipeline(%Backend{} = backend) do
     case find_pipeline_pid(backend) do
       nil ->
@@ -81,7 +81,7 @@ defmodule Logflare.Backends.ConsolidatedSup do
   @doc """
   Checks if a consolidated pipeline is running for a backend.
   """
-  @spec pipeline_running?(Backend.t() | pos_integer()) :: boolean()
+  @spec pipeline_running?(Backend.t() | non_neg_integer()) :: boolean()
   def pipeline_running?(%Backend{} = backend) do
     find_pipeline_pid(backend) != nil
   end
diff --git a/lib/logflare/backends/consolidated_sup_worker.ex b/lib/logflare/backends/consolidated_sup_worker.ex
index 25cff8333a..8dce0357c7 100644
--- a/lib/logflare/backends/consolidated_sup_worker.ex
+++ b/lib/logflare/backends/consolidated_sup_worker.ex
@@ -52,9 +52,19 @@ defmodule Logflare.Backends.ConsolidatedSupWorker do
   end
 
   defp list_expected_backend_ids do
-    Backends.list_backends(has_sources_or_rules: true)
-    |> Enum.filter(&Adaptor.consolidated_ingest?/1)
-    |> Enum.map(& &1.id)
+    default_backend_ids =
+      case Backends.get_single_tenant_default_backend() do
+        nil -> []
+        backend -> [backend.id]
+      end
+
+    backend_ids =
+      Backends.list_backends(has_sources_or_rules: true)
+      |> Enum.filter(&Adaptor.consolidated_ingest?/1)
+      |> Enum.map(& &1.id)
+
+    default_backend_ids
+    |> Enum.concat(backend_ids)
     |> MapSet.new()
   end
 
diff --git a/lib/logflare/backends/ingest_event_queue.ex b/lib/logflare/backends/ingest_event_queue.ex
index abb41b2026..8e043c153b 100644
--- a/lib/logflare/backends/ingest_event_queue.ex
+++ b/lib/logflare/backends/ingest_event_queue.ex
@@ -46,8 +46,8 @@ defmodule Logflare.Backends.IngestEventQueue do
   @type table_key :: {pos_integer(), pos_integer() | nil, pid() | nil}
   @type table_obj :: {table_key(), :ets.tid()}
   @type queues_key :: {pos_integer(), pos_integer() | nil}
-  @type consolidated_queues_key :: {:consolidated, pos_integer()}
-  @type consolidated_table_key :: {:consolidated, pos_integer(), pid() | nil}
+  @type consolidated_queues_key :: {:consolidated, non_neg_integer()}
+  @type consolidated_table_key :: {:consolidated, non_neg_integer(), pid() | nil}
   @type spool_producer_queues_key :: {:spool_producer, nil}
   @type spool_producer_table_key :: {:spool_producer, nil, pid() | nil}
   @type pointer_batch_key ::
diff --git a/lib/logflare/backends/ingest_event_queue/queue_janitor.ex b/lib/logflare/backends/ingest_event_queue/queue_janitor.ex
index e0cdac926e..e4fc5c4fee 100644
--- a/lib/logflare/backends/ingest_event_queue/queue_janitor.ex
+++ b/lib/logflare/backends/ingest_event_queue/queue_janitor.ex
@@ -88,7 +88,7 @@ defmodule Logflare.Backends.IngestEventQueue.QueueJanitor do
   @spec drop_queue(
           map(),
           {pos_integer(), pos_integer() | nil, pid() | nil}
-          | {:consolidated, pos_integer(), pid() | nil},
+          | {:consolidated, non_neg_integer(), pid() | nil},
           IngestEventQueue.queues_key() | IngestEventQueue.consolidated_queues_key(),
           pid() | nil,
           boolean(),
diff --git a/lib/logflare/backends/source_sup.ex b/lib/logflare/backends/source_sup.ex
index 43f8117214..efc6caa981 100644
--- a/lib/logflare/backends/source_sup.ex
+++ b/lib/logflare/backends/source_sup.ex
@@ -103,11 +103,9 @@ defmodule Logflare.Backends.SourceSup do
   defp init_children(source) do
     ingest_backends =
       Backends.Cache.list_backends(source_id: source.id)
-      |> Enum.reject(& &1.consolidated_ingest?)
 
     rules_backends =
       Backends.Cache.list_backends(rules_source_id: source.id)
-      |> Enum.reject(& &1.consolidated_ingest?)
       |> Enum.map(&%{&1 | register_for_ingest: false})
 
     user = Users.Cache.get(source.user_id)
@@ -119,6 +117,8 @@ defmodule Logflare.Backends.SourceSup do
     specs =
       [default_backend | ingest_backends]
       |> Enum.concat(rules_backends)
+      |> Enum.reject(&is_nil/1)
+      |> Enum.reject(& &1.consolidated_ingest?)
       |> Enum.map(&Backend.child_spec(source, &1))
       |> Enum.uniq()
 
diff --git a/lib/logflare/networking.ex b/lib/logflare/networking.ex
index 21e60766b8..f0039502b0 100644
--- a/lib/logflare/networking.ex
+++ b/lib/logflare/networking.ex
@@ -4,7 +4,7 @@ defmodule Logflare.Networking do
   alias Logflare.Backends
   alias Logflare.Backends.Adaptor.BigQueryAdaptor.GoogleApiClient
   alias Logflare.Backends.Adaptor.DatadogAdaptor
-  alias Logflare.SingleTenant
+  alias Logflare.Backends
 
   # Finch bounds only connect and receive. Without `send_timeout` a peer that accepts
   # the connection and then stops reading blocks the insert inside `:gen_tcp.send`
@@ -20,14 +20,14 @@ defmodule Logflare.Networking do
   @spool_pool_size 150
 
   def pools do
-    if SingleTenant.postgres_backend?() do
-      finch_pools(true)
+    if Backends.bigquery_default_backend?() do
+      bigquery_finch_pools() ++ grpc_pools()
     else
-      finch_pools(false) ++ grpc_pools()
+      base_finch_pools_with_default()
     end
   end
 
-  defp finch_pools(true = _postgres_backend?) do
+  defp base_finch_pools_with_default do
     [
       {Finch,
        name: Logflare.FinchDefaultHttp1, pools: %{default: [protocols: [:http1], size: 50]}},
@@ -43,7 +43,7 @@ defmodule Logflare.Networking do
     ]
   end
 
-  defp finch_pools(false = _postgres_backend?) do
+  defp bigquery_finch_pools do
     base = System.schedulers_online()
     http1_count = max(div(base, 4), 1)
 
diff --git a/lib/logflare/pubsub_rates/cache.ex b/lib/logflare/pubsub_rates/cache.ex
index 0bc767f83e..3b7c01a943 100644
--- a/lib/logflare/pubsub_rates/cache.ex
+++ b/lib/logflare/pubsub_rates/cache.ex
@@ -56,6 +56,7 @@ defmodule Logflare.PubSubRates.Cache do
   Merges a node map into the local cache.
   """
   @typep node_buffers :: %{atom() => non_neg_integer()}
+
   @spec cache_buffers(non_neg_integer() | :consolidated, non_neg_integer() | nil, node_buffers()) ::
           {:ok, true}
   def cache_buffers(:consolidated, backend_id, buffers) when is_integer(backend_id),
@@ -97,8 +98,12 @@ defmodule Logflare.PubSubRates.Cache do
   Returns the sum of all buffers across the cluster for a given source and backend combination.
   """
   @spec get_cluster_buffers(non_neg_integer()) :: non_neg_integer()
-  @spec get_cluster_buffers(non_neg_integer(), non_neg_integer() | nil) :: non_neg_integer()
-  def get_cluster_buffers(source_id, backend_id \\ nil) when is_integer(source_id) do
+  @spec get_cluster_buffers(non_neg_integer() | :consolidated, non_neg_integer() | nil) ::
+          non_neg_integer()
+
+  def get_cluster_buffers(source_id, backend_id \\ nil)
+      when is_integer(source_id) or
+             (source_id == :consolidated and is_integer(backend_id)) do
     case get_buffers(source_id, backend_id) do
       {:ok, node_buffers} when node_buffers != nil -> merge_buffers(node_buffers)
       _ -> 0
diff --git a/lib/logflare/single_tenant.ex b/lib/logflare/single_tenant.ex
index e60b969343..384780c454 100644
--- a/lib/logflare/single_tenant.ex
+++ b/lib/logflare/single_tenant.ex
@@ -55,6 +55,8 @@ defmodule Logflare.SingleTenant do
     "pgbouncer.logs.prod"
   ]
 
+  @type backend_type :: :bigquery | :clickhouse | :postgres
+
   defp endpoint_params do
     [
       %{
@@ -125,6 +127,17 @@ defmodule Logflare.SingleTenant do
     end
   end
 
+  @doc "Ensures the selected single-tenant ClickHouse pipeline is running"
+  @spec ensure_default_backend() :: :ok
+  def ensure_default_backend do
+    if clickhouse_backend?() do
+      get_default_backend()
+      |> Backends.maybe_restart_consolidated_pipeline()
+    end
+
+    :ok
+  end
+
   @doc """
   Create access tokens
   """
@@ -261,10 +274,10 @@ defmodule Logflare.SingleTenant do
   end
 
   defp start_supabase_source(source) do
-    if postgres_backend?() do
-      Backends.start_source_sup(source)
-    else
+    if bigquery_backend?() do
       Supervisor.ensure_started(source)
+    else
+      Backends.start_source_sup(source)
     end
   end
 
@@ -294,18 +307,47 @@ defmodule Logflare.SingleTenant do
   @spec single_tenant? :: boolean()
   def single_tenant?, do: !!Application.get_env(:logflare, :single_tenant)
 
+  @doc "Builds ClickHouse adapter configuration from a connection URL"
+  @spec clickhouse_backend_adapter_opts_from_url!(String.t()) :: keyword()
+  def clickhouse_backend_adapter_opts_from_url!(url) when is_binary(url) do
+    uri = parse_clickhouse_backend_url!(url)
+    {username, password} = clickhouse_credentials(uri)
+
+    sanitized_url =
+      uri
+      |> Map.merge(%{userinfo: nil, path: nil, query: nil, fragment: nil})
+      |> URI.to_string()
+
+    [
+      url: sanitized_url,
+      username: username,
+      password: password,
+      database: clickhouse_database(uri),
+      port: clickhouse_port(url, uri.scheme)
+    ]
+    |> Enum.reject(fn {_key, value} -> is_nil(value) end)
+  end
+
   @doc "Returns true if supabase mode flag is set via config and if is single tenant"
   @spec supabase_mode? :: boolean()
   def supabase_mode?, do: !!Application.get_env(:logflare, :supabase_mode) and single_tenant?()
 
-  @doc "Returns postgres backend adapter configurations if single tenant and env is set"
-  @spec postgres_backend_adapter_opts :: Keyword.t() | nil
+  @doc "Returns PostgreSQL backend adapter configuration in single-tenant mode"
+  @spec postgres_backend_adapter_opts :: keyword() | nil
   def postgres_backend_adapter_opts do
     if single_tenant?() do
       Application.get_env(:logflare, :postgres_backend_adapter)
     end
   end
 
+  @doc "Returns ClickHouse backend adapter configuration when selected in single-tenant mode"
+  @spec clickhouse_backend_adapter_opts :: keyword() | nil
+  def clickhouse_backend_adapter_opts do
+    if clickhouse_backend?() do
+      Application.get_env(:logflare, :clickhouse_backend_adapter)
+    end
+  end
+
   @doc """
   Adds ingestion samples for supabase sources, so that schema is built and stored correctly.
   """
@@ -359,7 +401,7 @@ defmodule Logflare.SingleTenant do
 
     source_schemas_updated =
       cond do
-        postgres_backend?() -> :ok
+        not bigquery_backend?() -> :ok
         # for mocking, use full qualified function name
         __MODULE__.supabase_mode_source_schemas_updated?() -> :ok
         true -> nil
@@ -375,26 +417,29 @@ defmodule Logflare.SingleTenant do
   end
 
   @doc """
-  Returns true if postgres backend is enabled for single tenant
+  Returns the selected single-tenant backend type.
   """
+  @spec backend_type :: backend_type()
+  def backend_type do
+    Application.get_env(:logflare, :single_tenant_backend) || :bigquery
+  end
+
+  @doc "Returns true if BigQuery is selected in single-tenant mode"
+  @spec bigquery_backend? :: boolean()
+  def bigquery_backend? do
+    selected_backend?(:bigquery)
+  end
+
+  @doc "Returns true if PostgreSQL is selected in single-tenant mode"
   @spec postgres_backend? :: boolean()
   def postgres_backend? do
-    opts = postgres_backend_adapter_opts() || []
-
-    url = Keyword.get(opts, :url)
-    single_tenant?() && url != nil
+    selected_backend?(:postgres)
   end
 
-  @doc """
-  Returns the type of the default backend
-  """
-  @spec backend_type :: :postgres | :bigquery
-  def backend_type do
-    if postgres_backend?() do
-      :postgres
-    else
-      :bigquery
-    end
+  @doc "Returns true if ClickHouse is selected in single-tenant mode"
+  @spec clickhouse_backend? :: boolean()
+  def clickhouse_backend? do
+    selected_backend?(:clickhouse)
   end
 
   def supabase_mode_source_schemas_updated? do
@@ -423,4 +468,40 @@ defmodule Logflare.SingleTenant do
     |> File.read!()
     |> Jason.decode!()
   end
+
+  defp parse_clickhouse_backend_url!(url) do
+    case URI.parse(url) do
+      %URI{host: host} = uri when host not in [nil, ""] -> uri
+      %URI{} -> raise "CLICKHOUSE_BACKEND_URL must include a hostname"
+    end
+  end
+
+  defp clickhouse_database(%URI{path: path}) when path in [nil, "", "/"], do: "default"
+
+  defp clickhouse_database(%URI{path: path}) do
+    path
+    |> String.trim_leading("/")
+    |> URI.decode()
+  end
+
+  defp clickhouse_credentials(%URI{userinfo: nil}), do: {nil, nil}
+
+  defp clickhouse_credentials(%URI{userinfo: userinfo}) do
+    case String.split(userinfo, ":", parts: 2) do
+      [username, password] -> {URI.decode(username), URI.decode(password)}
+      [username] -> {URI.decode(username), nil}
+    end
+  end
+
+  defp clickhouse_port(url, scheme) do
+    case :uri_string.parse(url) do
+      %{port: port} -> port
+      _uri when scheme == "https" -> 8443
+      _uri -> 8123
+    end
+  end
+
+  defp selected_backend?(backend_type) do
+    single_tenant?() and backend_type() == backend_type
+  end
 end
diff --git a/lib/logflare/sources.ex b/lib/logflare/sources.ex
index e2aacdd871..eb30b3e6b4 100644
--- a/lib/logflare/sources.ex
+++ b/lib/logflare/sources.ex
@@ -15,7 +15,6 @@ defmodule Logflare.Sources do
   alias Logflare.Logs.RejectedLogEvents
   alias Logflare.PubSubRates
   alias Logflare.Repo
-  alias Logflare.SingleTenant
   alias Logflare.SourceSchemas
   alias Logflare.Sources
   alias Logflare.Sources.Source
@@ -132,7 +131,7 @@ defmodule Logflare.Sources do
            |> Ecto.build_assoc(:sources)
            |> Source.update_by_user_changeset(source_params)
            |> Repo.insert() do
-      if !SingleTenant.postgres_backend?() do
+      if Backends.bigquery_default_backend?() do
         create_big_query_schema_and_start_source(source)
       end
 
@@ -249,7 +248,8 @@ defmodule Logflare.Sources do
     source = put_retention_days(source)
     updated = put_retention_days(updated)
 
-    if source.retention_days != updated.retention_days and not SingleTenant.postgres_backend?() do
+    if source.retention_days != updated.retention_days and
+         Backends.bigquery_default_backend?() do
       user = Users.Cache.get(updated.user_id)
 
       BigQuery.patch_table_ttl(
@@ -261,7 +261,7 @@ defmodule Logflare.Sources do
     end
 
     if source.bigquery_clustering_fields != updated.bigquery_clustering_fields and
-         not SingleTenant.postgres_backend?() do
+         Backends.bigquery_default_backend?() do
       user = Users.Cache.get(updated.user_id)
 
       fields = String.split(updated.bigquery_clustering_fields || "", ",") ++ ["timestamp"]
@@ -666,26 +666,24 @@ defmodule Logflare.Sources do
   end
 
   @spec calculate_total_pending(Source.t()) :: non_neg_integer()
-  defp calculate_total_pending(%Source{id: source_id} = source) do
-    # Get all backends for this source, including default backend
-    user = Users.Cache.get(source.user_id)
-    default_backend = Backends.get_default_backend(user)
-
+  defp calculate_total_pending(%Source{} = source) do
     ingest_backends = Backends.Cache.list_backends(source_id: source.id)
 
     rules_backends =
       Backends.Cache.list_backends(rules_source_id: source.id)
       |> Enum.map(&%{&1 | register_for_ingest: false})
 
-    all_backends = [default_backend | ingest_backends] ++ rules_backends
+    backend_queue_keys =
+      (ingest_backends ++ rules_backends)
+      |> Enum.map(&Backends.ingest_queue_key(source, &1))
+
+    queue_keys = [Backends.system_default_ingest_queue_key(source) | backend_queue_keys]
 
     # Sum pending items across all backends
-    all_backends
-    |> Enum.reduce(0, fn backend, acc ->
-      case Backends.IngestEventQueue.total_pending({source_id, backend.id}) do
-        count -> acc + count
-      end
-    end)
+    queue_keys
+    |> Enum.reject(&is_nil/1)
+    |> Enum.uniq()
+    |> Enum.reduce(0, &(Backends.IngestEventQueue.total_pending(&1) + &2))
   end
 
   @spec has_recent_logs_within?(Source.t(), non_neg_integer()) :: boolean()
diff --git a/lib/logflare/sources/source/rate_counter_server.ex b/lib/logflare/sources/source/rate_counter_server.ex
index 9b0e3ad1bd..80d3f47336 100644
--- a/lib/logflare/sources/source/rate_counter_server.ex
+++ b/lib/logflare/sources/source/rate_counter_server.ex
@@ -8,7 +8,6 @@ defmodule Logflare.Sources.Source.RateCounterServer do
   alias Logflare.Backends
   alias Logflare.Google.BigQuery.GenUtils
   alias Logflare.PubSubRates
-  alias Logflare.SingleTenant
   alias Logflare.Source.Data
   alias Logflare.Sources
   alias Logflare.Sources.Counters
@@ -64,7 +63,7 @@ defmodule Logflare.Sources.Source.RateCounterServer do
     put_current_rate()
 
     bigquery_project_id =
-      if !SingleTenant.postgres_backend?() do
+      if Backends.bigquery_default_backend?() do
         GenUtils.get_project_id(source_token)
       end
 
diff --git a/lib/logflare/sources/source/supervisor.ex b/lib/logflare/sources/source/supervisor.ex
index f37eeb4195..11a709a09e 100644
--- a/lib/logflare/sources/source/supervisor.ex
+++ b/lib/logflare/sources/source/supervisor.ex
@@ -11,12 +11,9 @@ defmodule Logflare.Sources.Source.Supervisor do
   alias Logflare.SourceSchemas
   alias Logflare.Sources
   alias Logflare.Sources.Counters
-  alias Logflare.Google.BigQuery
-  alias Logflare.ContextCache
-  alias Logflare.SourceSchemas
-  alias Logflare.Backends
-  alias Logflare.Utils.Tasks
   alias Logflare.Sources.Source
+  alias Logflare.Utils.Tasks
+
   require Logger
 
   # TODO: Move all manager fns into a manager server so errors in manager fns don't kill the whole supervision tree
@@ -108,7 +105,7 @@ defmodule Logflare.Sources.Source.Supervisor do
   def delete_source(source_token) do
     GenServer.abcast(__MODULE__, {:stop, source_token})
     # TODO: move to adaptor callback
-    unless do_pg_ops?() do
+    if Backends.bigquery_default_backend?() do
       BigQuery.delete_table(source_token)
     end
 
@@ -121,7 +118,7 @@ defmodule Logflare.Sources.Source.Supervisor do
   end
 
   def reset_source(source_token) do
-    unless do_pg_ops?() do
+    if Backends.bigquery_default_backend?() do
       GenServer.abcast(__MODULE__, {:restart, source_token})
     end
 
@@ -140,14 +137,9 @@ defmodule Logflare.Sources.Source.Supervisor do
     |> Enum.each(fn s -> reset_source(s.token) end)
   end
 
-  defp do_pg_ops? do
-    !!Application.get_env(:logflare, :single_tenant) &&
-      !!Application.get_env(:logflare, :postgres_backend_adapter)
-  end
-
   defp create_source(%Source{} = source) do
     with {:ok, _pid} = res <- do_start_source_sup(source),
-         :ok <- init_table(source.token) do
+         :ok <- maybe_init_table(source.token) do
       res
     else
       {:error, :already_started} = err ->
@@ -168,6 +160,10 @@ defmodule Logflare.Sources.Source.Supervisor do
     end
   end
 
+  defp maybe_init_table(source_token) do
+    if Backends.bigquery_default_backend?(), do: init_table(source_token), else: :ok
+  end
+
   @spec ensure_started(Source.t()) :: :ok
   def ensure_started(%Source{token: source_token} = source) do
     # Check if already running
diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs
new file mode 100644
index 0000000000..e7dffb6f70
--- /dev/null
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs
@@ -0,0 +1,99 @@
+defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.SingleTenantIngestionTest do
+  use Logflare.DataCase, async: false
+
+  alias Logflare.Backends.Adaptor.ClickHouseAdaptor
+  alias Logflare.Backends.Adaptor.ClickHouseAdaptor.ConnectionManager
+  alias Logflare.Backends.Adaptor.ClickHouseAdaptor.Provisioner
+  alias Logflare.SingleTenant
+  alias Logflare.SystemMetrics.AllLogsLogged
+
+  TestUtils.setup_single_tenant(
+    backend_type: :clickhouse,
+    seed_user: true,
+    clickhouse_backend_adapter_opts: [
+      url: "http://localhost:8123",
+      database: "logflare_test",
+      username: "logflare",
+      password: "logflare",
+      port: 8123,
+      ingest_pool_size: 5,
+      query_pool_size: 3
+    ]
+  )
+
+  setup do
+    insert(:plan, name: "Free")
+
+    user = SingleTenant.get_default_user()
+    source = insert(:source, user: user)
+    backend = Logflare.Backends.get_default_backend(user)
+
+    start_supervised!(AllLogsLogged)
+    {:ok, connection_manager_pid} = ConnectionManager.start_link(backend)
+    {:ok, supervisor_pid} = ClickHouseAdaptor.start_link(backend)
+
+    cleanup_single_tenant_tables(backend)
+
+    on_exit(fn ->
+      cleanup_single_tenant_tables(backend)
+
+      if Process.alive?(supervisor_pid) do
+        Process.exit(supervisor_pid, :shutdown)
+      end
+
+      if Process.alive?(connection_manager_pid) do
+        Process.exit(connection_manager_pid, :shutdown)
+      end
+    end)
+
+    [source: source, backend: backend]
+  end
+
+  test "the pipeline consumes normally ingested events", %{
+    source: source,
+    backend: backend
+  } do
+    {:ok, provisioner_pid} = Provisioner.start_link(backend)
+    provisioner_ref = Process.monitor(provisioner_pid)
+    assert_receive {:DOWN, ^provisioner_ref, :process, ^provisioner_pid, :normal}, 5_000
+
+    message = "synthetic pipeline #{System.unique_integer([:positive])}"
+    assert {:ok, 1} = Logflare.Backends.ingest_logs([%{"message" => message}], source)
+
+    table_name = ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :log)
+
+    TestUtils.retry_assert([duration: 10_000], fn ->
+      assert {:ok, {[%{"count" => 1}], _bytes}} =
+               ClickHouseAdaptor.execute_ch_query(
+                 backend,
+                 "SELECT count(*) AS count FROM #{table_name} WHERE event_message = {message:String}",
+                 %{message: message}
+               )
+    end)
+  end
+
+  defp cleanup_single_tenant_tables(backend) do
+    {manager_pid, stop_manager?} =
+      case ConnectionManager.start_link(backend) do
+        {:ok, pid} ->
+          Process.unlink(pid)
+          {pid, true}
+
+        {:error, {:already_started, pid}} ->
+          {pid, false}
+      end
+
+    try do
+      for event_type <- [:log, :metric, :trace] do
+        table_name = ClickHouseAdaptor.clickhouse_ingest_table_name(backend, event_type)
+        ClickHouseAdaptor.execute_ch_query(backend, "DROP TABLE IF EXISTS #{table_name}")
+      end
+    after
+      if stop_manager? and Process.alive?(manager_pid) do
+        GenServer.stop(manager_pid)
+      end
+    end
+
+    :ok
+  end
+end
diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
index ed43b09616..35c6ed3ba1 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
@@ -58,6 +58,19 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :trace) ==
                "otel_traces_#{stringified_backend_token}"
     end
+
+    test "uses fixed table names for the synthetic single-tenant backend", %{backend: backend} do
+      backend = %{backend | id: 0, single_tenant_default?: true}
+
+      assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :log) ==
+               "otel_logs_single_tenant"
+
+      assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :metric) ==
+               "otel_metrics_single_tenant"
+
+      assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :trace) ==
+               "otel_traces_single_tenant"
+    end
   end
 
   describe "connection and basic functionality" do
diff --git a/test/logflare/backends/backend_test.exs b/test/logflare/backends/backend_test.exs
index e87d6b32c3..1f8efbb040 100644
--- a/test/logflare/backends/backend_test.exs
+++ b/test/logflare/backends/backend_test.exs
@@ -139,5 +139,21 @@ defmodule Logflare.Backends.BackendTest do
                "Backend type webhook does not support default ingest"
              ]
     end
+
+    test "does not allow the single-tenant default marker changeset", %{
+      user: user
+    } do
+      attrs = %{
+        name: "Test ClickHouse Backend",
+        type: :clickhouse,
+        config: %{url: "http://localhost:8123", database: "default", port: 8123},
+        single_tenant_default?: true
+      }
+
+      changeset = Backend.changeset(Ecto.build_assoc(user, :backends), attrs)
+
+      assert changeset.valid?
+      refute get_field(changeset, :single_tenant_default?)
+    end
   end
 end
diff --git a/test/logflare/backends/consolidated_sup_worker_test.exs b/test/logflare/backends/consolidated_sup_worker_test.exs
index cd3ae8ffe6..6066be676a 100644
--- a/test/logflare/backends/consolidated_sup_worker_test.exs
+++ b/test/logflare/backends/consolidated_sup_worker_test.exs
@@ -1,6 +1,7 @@
 defmodule Logflare.Backends.ConsolidatedSupWorkerTest do
   use Logflare.DataCase, async: false
 
+  alias Logflare.Backends
   alias Logflare.Backends.ConsolidatedSup
   alias Logflare.Backends.ConsolidatedSupWorker
 
@@ -77,4 +78,26 @@ defmodule Logflare.Backends.ConsolidatedSupWorkerTest do
       refute ConsolidatedSup.pipeline_running?(backend.id)
     end
   end
+
+  describe "ConsolidatedSupWorker single-tenant default" do
+    TestUtils.setup_single_tenant(seed_user: true, backend_type: :clickhouse)
+
+    test "starts the synthetic consolidated backend without sources or rules" do
+      backend = Backends.get_single_tenant_default_backend()
+      assert backend.id == 0
+
+      on_exit(fn -> ConsolidatedSup.stop_pipeline(backend.id) end)
+
+      refute ConsolidatedSup.pipeline_running?(backend.id)
+      worker = start_supervised!({ConsolidatedSupWorker, [interval: 10_000]})
+
+      send(worker, :check)
+
+      TestUtils.retry_assert(fn ->
+        assert ConsolidatedSup.pipeline_running?(backend.id)
+      end)
+
+      assert Backends.list_backends(user_id: backend.user_id) == []
+    end
+  end
 end
diff --git a/test/logflare/backends/ingest_event_queue_test.exs b/test/logflare/backends/ingest_event_queue_test.exs
index 5bdd37039f..58669a925f 100644
--- a/test/logflare/backends/ingest_event_queue_test.exs
+++ b/test/logflare/backends/ingest_event_queue_test.exs
@@ -1804,7 +1804,7 @@ defmodule Logflare.Backends.IngestEventQueueTest do
     end
   end
 
-  test "BufferCacheWorker caches buffer lengths every n seconds" do
+  test "BufferCacheWorker caches source and consolidated buffer lengths every n seconds" do
     user = insert(:user)
     source = insert(:source, user: user)
     backend = insert(:backend, user: user)
@@ -1812,19 +1812,27 @@ defmodule Logflare.Backends.IngestEventQueueTest do
 
     table = {source.id, backend.id, pid}
     other_table = {source.id, nil, pid}
+    consolidated_table = {:consolidated, backend.id, pid}
 
     IngestEventQueue.upsert_tid(table)
     IngestEventQueue.upsert_tid(other_table)
+    IngestEventQueue.upsert_tid(consolidated_table)
     start_supervised!({BufferCacheWorker, interval: 100})
 
     le = build(:log_event, source: source)
     IngestEventQueue.add_to_table(table, [le])
     IngestEventQueue.add_to_table(other_table, [le])
+    IngestEventQueue.add_to_table(consolidated_table, [le])
+    node = Node.self()
 
     # Verify worker cached the values automatically (without manual cache calls)
     TestUtils.retry_assert(fn ->
       assert PubSubRates.Cache.get_cluster_buffers(source.id, backend.id) == 1
       assert PubSubRates.Cache.get_cluster_buffers(source.id, nil) == 1
+      assert PubSubRates.Cache.get_cluster_buffers(:consolidated, backend.id) == 1
+
+      assert {:ok, %{^node => %{len: 1}}} =
+               Cachex.get(PubSubRates.Cache, {:consolidated, backend.id, "buffers"})
     end)
   end
 
diff --git a/test/logflare/backends/spool/memory_monitor_test.exs b/test/logflare/backends/spool/memory_monitor_test.exs
index 7c0bf2167f..1e1f76d117 100644
--- a/test/logflare/backends/spool/memory_monitor_test.exs
+++ b/test/logflare/backends/spool/memory_monitor_test.exs
@@ -223,7 +223,11 @@ defmodule Logflare.Backends.Spool.MemoryMonitorTest do
       # completely backlogged and it would report "not full" regardless.
       backend = insert(:backend, user: user, type: :clickhouse, default_ingest?: false)
       {:ok, _source} = Backends.update_source_backends(source, [backend])
-      backend_table_key = {source.id, backend.id, self()}
+
+      {queue_owner, backend_id} =
+        Backends.ingest_queue_key(source, Backends.get_backend(backend.id))
+
+      backend_table_key = {queue_owner, backend_id, self()}
       IngestEventQueue.upsert_tid(backend_table_key)
 
       fill_queue(backend_table_key)
diff --git a/test/logflare/backends_test.exs b/test/logflare/backends_test.exs
index f0a1b978d1..a3c430f64c 100644
--- a/test/logflare/backends_test.exs
+++ b/test/logflare/backends_test.exs
@@ -1396,6 +1396,22 @@ defmodule Logflare.BackendsTest do
       end)
     end
 
+    test "starts a non-shared default backend for the source", %{
+      source: source,
+      user: user
+    } do
+      default_backend = insert(:backend, type: :webhook, user: user)
+      default_backend = Backends.get_backend(default_backend.id)
+
+      stub(Backends, :get_default_backend, fn %User{id: user_id} when user_id == user.id ->
+        default_backend
+      end)
+
+      start_supervised!({SourceSup, source})
+
+      assert SourceSup.backend_child_started?(default_backend.id, source.id)
+    end
+
     test "SourceSup filters out consolidated backends", %{source: source, user: user} do
       consolidated_backend =
         insert(:backend,
@@ -1540,7 +1556,7 @@ defmodule Logflare.BackendsTest do
     test "any_ingest_queue_over_limit?/1 is true for a backend that is not flagged default_ingest?",
          %{source: source} do
       user = Repo.get(User, source.user_id)
-      backend = insert(:backend, user: user, type: :clickhouse, default_ingest?: false)
+      backend = insert(:backend, user: user, type: :postgres, default_ingest?: false)
       {:ok, _} = Backends.update_source_backends(source, [backend])
 
       table_key = {source.id, backend.id, self()}
@@ -1607,6 +1623,60 @@ defmodule Logflare.BackendsTest do
     end
   end
 
+  describe "single-tenant ClickHouse default backend" do
+    TestUtils.setup_single_tenant(backend_type: :clickhouse)
+
+    setup do
+      insert(:plan)
+      user = insert(:user)
+      source = insert(:source, user: user)
+      backend = Backends.get_default_backend(user)
+
+      [backend: backend, source: source]
+    end
+
+    test "does not start ingestion separately for each source", %{
+      backend: backend,
+      source: source
+    } do
+      start_supervised!({SourceSup, source})
+
+      refute SourceSup.backend_child_started?(backend.id, source.id)
+    end
+
+    test "sends events only to shared queue", %{
+      backend: backend,
+      source: source
+    } do
+      {:ok, _} = Registry.register(Logflare.Backends.SourceRegistry, {source.id, SourceSup}, nil)
+      IngestEventQueue.upsert_tid({:consolidated, backend.id, nil})
+      IngestEventQueue.upsert_tid({source.id, nil, nil})
+
+      assert {:ok, 1} = Backends.ingest_logs([build(:log_event, source: source)], source)
+
+      assert {:ok, [_]} = IngestEventQueue.fetch_events({:consolidated, backend.id}, 10)
+
+      assert {:ok, []} = IngestEventQueue.fetch_events({source.id, nil}, 10)
+    end
+
+    test "checks only shared queue for overflow", %{
+      backend: backend,
+      source: source
+    } do
+      legacy_table_key = {source.id, nil, self()}
+      IngestEventQueue.upsert_tid(legacy_table_key)
+      fill_queue_over_limit(legacy_table_key)
+
+      refute Backends.any_ingest_queue_over_limit?(source.id)
+
+      consolidated_table_key = {:consolidated, backend.id, self()}
+      IngestEventQueue.upsert_tid(consolidated_table_key)
+      fill_queue_over_limit(consolidated_table_key)
+
+      assert Backends.any_ingest_queue_over_limit?(source.id)
+    end
+  end
+
   describe "ingest filters" do
     setup do
       insert(:plan)
diff --git a/test/logflare/networking_test.exs b/test/logflare/networking_test.exs
index 0a7fc63ad2..9b73a96cd8 100644
--- a/test/logflare/networking_test.exs
+++ b/test/logflare/networking_test.exs
@@ -5,6 +5,20 @@ defmodule Logflare.NetworkingTest do
   alias Logflare.Backends.Adaptor.DatadogAdaptor
   alias Logflare.Networking
 
+  describe "multi-tenant mode" do
+    setup :use_non_test_networking_config
+
+    test "returns BigQuery, gRPC, and ClickHouse connection pools" do
+      assert Logflare.FinchGoth in finch_names()
+      assert Logflare.FinchIngest in finch_names()
+      assert Logflare.FinchQuery in finch_names()
+      assert Logflare.FinchClickHouseIngest in finch_names()
+
+      assert {Logflare.Networking.GrpcPool, _opts} =
+               Enum.find(Networking.pools(), &match?({Logflare.Networking.GrpcPool, _}, &1))
+    end
+  end
+
   describe "single tenant mode using Big Query" do
     TestUtils.setup_single_tenant()
 
@@ -16,15 +30,7 @@ defmodule Logflare.NetworkingTest do
     end
 
     test "returns bigquery, clickhouse, and spool connection pools" do
-      finch_names =
-        Networking.pools()
-        |> Enum.filter(fn
-          {mod, _} -> mod == Finch
-          _ -> false
-        end)
-        |> Enum.map(fn {Finch, opts} -> Keyword.get(opts, :name) end)
-
-      assert finch_names == [
+      assert finch_names() == [
                Logflare.FinchGoth,
                Logflare.FinchDefaultHttp1,
                Logflare.FinchIngest,
@@ -193,4 +199,25 @@ defmodule Logflare.NetworkingTest do
       end
     end
   end
+
+  describe "single tenant mode using ClickHouse" do
+    TestUtils.setup_single_tenant(backend_type: :clickhouse)
+    setup :use_non_test_networking_config
+
+    test "excludes BigQuery and gRPC connection pools" do
+      assert finch_names() == [
+               Logflare.FinchDefault,
+               Logflare.FinchClickHouseIngest,
+               Logflare.FinchClickHouseAsyncIngest
+             ]
+
+      refute Enum.any?(Networking.pools(), &match?({Logflare.Networking.GrpcPool, _}, &1))
+    end
+  end
+
+  defp use_non_test_networking_config(_context) do
+    previous_env = Application.get_env(:logflare, :env)
+    Application.put_env(:logflare, :env, :dev)
+    on_exit(fn -> Application.put_env(:logflare, :env, previous_env) end)
+  end
 end
diff --git a/test/logflare/single_tenant_test.exs b/test/logflare/single_tenant_test.exs
index 1605762789..e415bad97a 100644
--- a/test/logflare/single_tenant_test.exs
+++ b/test/logflare/single_tenant_test.exs
@@ -2,19 +2,53 @@ defmodule Logflare.SingleTenantTest do
   @moduledoc false
   use Logflare.DataCase
   import Logflare.Utils.Guards
-  alias Logflare.SingleTenant
+  alias Logflare.Auth
+  alias Logflare.Backends
+  alias Logflare.Backends.Adaptor.BigQueryAdaptor
+  alias Logflare.Backends.Backend
+  alias Logflare.Backends.ConsolidatedSup
   alias Logflare.Billing
-  alias Logflare.Users
-  alias Logflare.User
   alias Logflare.Billing.Plan
-  alias Logflare.Sources
   alias Logflare.Endpoints
-  alias Logflare.Sources.Source.BigQuery.Schema
+  alias Logflare.SingleTenant
+  alias Logflare.Sources
   alias Logflare.Sources.Source
-  alias Logflare.Auth
-  alias Logflare.Backends.Backend
-  alias Logflare.Backends
-  alias Logflare.Backends.Adaptor.BigQueryAdaptor
+  alias Logflare.Sources.Source.BigQuery.Schema
+  alias Logflare.User
+  alias Logflare.Users
+
+  describe "ClickHouse connection URL" do
+    test "builds adapter options from a URL" do
+      for {url, expected} <- [
+            {
+              "https://logflare%40example.com:s%3Acret@clickhouse.example.com:9440/otel%5Flogs",
+              [
+                url: "https://clickhouse.example.com:9440",
+                username: "logflare@example.com",
+                password: "s:cret",
+                database: "otel_logs",
+                port: 9440
+              ]
+            },
+            {
+              "https://localhost/logs",
+              [url: "https://localhost", database: "logs", port: 8443]
+            },
+            {
+              "http://localhost",
+              [url: "http://localhost", database: "default", port: 8123]
+            }
+          ] do
+        assert SingleTenant.clickhouse_backend_adapter_opts_from_url!(url) == expected
+      end
+    end
+
+    test "requires a hostname" do
+      assert_raise RuntimeError, ~r/must include a hostname/, fn ->
+        SingleTenant.clickhouse_backend_adapter_opts_from_url!("not-a-url")
+      end
+    end
+  end
 
   describe "single tenant mode using Big Query" do
     TestUtils.setup_single_tenant()
@@ -105,10 +139,13 @@ defmodule Logflare.SingleTenantTest do
       url = "postgresql://#{username}:#{password}@#{hostname}/#{database}"
 
       prev = Application.get_env(:logflare, :postgres_backend_adapter)
+      previous_backend = Application.get_env(:logflare, :single_tenant_backend)
       Application.put_env(:logflare, :postgres_backend_adapter, url: url)
+      Application.put_env(:logflare, :single_tenant_backend, :postgres)
 
       on_exit(fn ->
         Application.put_env(:logflare, :postgres_backend_adapter, prev)
+        Application.put_env(:logflare, :single_tenant_backend, previous_backend)
       end)
 
       [url: url, password: password]
@@ -138,6 +175,8 @@ defmodule Logflare.SingleTenantTest do
 
   test "single_tenant? returns false when not in single tenant mode" do
     refute SingleTenant.single_tenant?()
+    refute SingleTenant.bigquery_backend?()
+    assert Backends.bigquery_default_backend?()
   end
 
   describe "supabase_mode=true using Big Query" do
@@ -232,6 +271,56 @@ defmodule Logflare.SingleTenantTest do
     end
   end
 
+  describe "single tenant mode using ClickHouse" do
+    TestUtils.setup_single_tenant(
+      backend_type: :clickhouse,
+      clickhouse_backend_adapter_opts: [
+        url: "http://localhost:8123",
+        database: "logflare_test",
+        port: 8123
+      ]
+    )
+
+    test "startup uses a synthetic backend and skips BigQuery side effects" do
+      reject(BigQueryAdaptor, :create_managed_service_accounts, 0)
+      reject(BigQueryAdaptor, :update_iam_policy, 0)
+      reject(Schema, :update, 3)
+
+      expect(SingleTenant, :create_supabase_sources, fn -> {:ok, []} end)
+      expect(SingleTenant, :create_supabase_endpoints, fn -> {:ok, []} end)
+      expect(SingleTenant, :ensure_supabase_sources_started, fn -> :ok end)
+
+      previous_supabase_mode = Application.get_env(:logflare, :supabase_mode)
+      Application.put_env(:logflare, :supabase_mode, true)
+
+      on_exit(fn -> Application.put_env(:logflare, :supabase_mode, previous_supabase_mode) end)
+
+      Logflare.Application.startup_tasks()
+
+      user = SingleTenant.get_default_user()
+
+      assert %Backend{
+               id: 0,
+               token: "00000000-0000-0000-0000-000000000000",
+               user_id: user_id,
+               type: :clickhouse,
+               single_tenant_default?: true,
+               config: %{
+                 url: "http://localhost:8123",
+                 database: "logflare_test",
+                 port: 8123
+               }
+             } = backend = Backends.get_default_backend(user)
+
+      assert user.id == user_id
+      assert SingleTenant.get_default_backend() == backend
+      assert Backends.get_backend(0) == backend
+      assert Backends.list_backends(user_id: user_id) == []
+
+      on_exit(fn -> ConsolidatedSup.stop_pipeline(backend.id) end)
+    end
+  end
+
   describe "supabase_mode=true using Postgres" do
     TestUtils.setup_single_tenant(
       backend_type: :postgres,
diff --git a/test/logflare/sources_test.exs b/test/logflare/sources_test.exs
index 9dd03eba2e..1fa572bcb2 100644
--- a/test/logflare/sources_test.exs
+++ b/test/logflare/sources_test.exs
@@ -102,6 +102,33 @@ defmodule Logflare.SourcesTest do
     end
   end
 
+  describe "BigQuery source side effects with a single-tenant ClickHouse default" do
+    TestUtils.setup_single_tenant(backend_type: :clickhouse)
+
+    setup do
+      insert(:plan, name: "Free", limit_source_ttl: :timer.hours(24) * 20)
+      [user: insert(:user)]
+    end
+
+    test "creates a source without creating a BigQuery schema", %{user: user} do
+      assert {:ok, source} = Sources.create_source(%{name: TestUtils.random_string()}, user)
+      refute SourceSchemas.get_source_schema_by(source_id: source.id)
+    end
+
+    test "updates TTL and clustering without patching a BigQuery table", %{user: user} do
+      reject(BigQuery, :patch_table_ttl, 4)
+      reject(BigQuery, :patch_table_clustering, 4)
+
+      source = insert(:source, user: user, bigquery_clustering_fields: nil)
+
+      assert {:ok, %Source{retention_days: 12, bigquery_clustering_fields: "session_id"}} =
+               Sources.update_source(source, %{
+                 retention_days: 12,
+                 bigquery_clustering_fields: "session_id"
+               })
+    end
+  end
+
   describe "update_source/2 with different retention_days" do
     setup do
       user = insert(:user)
@@ -474,6 +501,42 @@ defmodule Logflare.SourcesTest do
     end
   end
 
+  describe "Source.Supervisor with a single-tenant ClickHouse default" do
+    TestUtils.setup_single_tenant(backend_type: :clickhouse)
+
+    setup do
+      reject(BigQuery, :init_table!, 6)
+      reject(BigQuery, :delete_table, 1)
+
+      insert(:plan)
+      user = insert(:user)
+
+      on_exit(fn ->
+        for {_id, child, _, _} <- DynamicSupervisor.which_children(Logflare.Backends.SourcesSup) do
+          DynamicSupervisor.terminate_child(Logflare.Backends.SourcesSup, child)
+        end
+      end)
+
+      [user: user]
+    end
+
+    test "starts and deletes a source without BigQuery table lifecycle calls", %{user: user} do
+      %{token: token} = source = insert(:source, user: user)
+      Sources.Cache.get_by_id(source.id)
+      start_supervised!(Source.Supervisor)
+
+      assert {:ok, ^token} = Source.Supervisor.start_source(token)
+      TestUtils.retry_assert(fn -> assert {:ok, _pid} = Backends.lookup(SourceSup, source) end)
+
+      assert {:ok, ^token} = Source.Supervisor.reset_source(token)
+      assert {:ok, ^token} = Source.Supervisor.delete_source(token)
+
+      TestUtils.retry_assert(fn ->
+        assert {:error, :not_started} = Backends.lookup(SourceSup, source)
+      end)
+    end
+  end
+
   test "ingest_ets_tables_started?/0" do
     assert Sources.ingest_ets_tables_started?()
   end
@@ -550,6 +613,39 @@ defmodule Logflare.SourcesTest do
     end
   end
 
+  describe "shutdown_idle_sources/0 with a single-tenant ClickHouse default" do
+    TestUtils.setup_single_tenant(backend_type: :clickhouse)
+
+    setup do
+      insert(:plan)
+      user = insert(:user)
+      source = insert(:source, user: user)
+
+      backend = Backends.get_default_backend(user)
+
+      Sources.Cache.get_by_id(source.id)
+      :ok = Backends.start_source_sup(source)
+
+      {:ok, source: source, backend: backend}
+    end
+
+    test "does not shut down a source while the consolidated default has pending events", %{
+      source: source,
+      backend: backend
+    } do
+      event = build(:log_event, source: source)
+      queue_key = {:consolidated, backend.id}
+      Backends.IngestEventQueue.upsert_tid({:consolidated, backend.id, self()})
+      Backends.IngestEventQueue.add_to_table(queue_key, [event])
+
+      assert Backends.system_default_ingest_queue_key(source) == queue_key
+      assert Backends.IngestEventQueue.total_pending(queue_key) == 1
+      TestUtils.retry_assert(fn -> assert Backends.source_sup_started?(source) end)
+      :ok = Sources.shutdown_idle_sources()
+      assert Backends.source_sup_started?(source)
+    end
+  end
+
   describe "list_sources/1" do
     setup do
       insert(:plan)
diff --git a/test/logflare_web/controllers/plugs/buffer_limiter_test.exs b/test/logflare_web/controllers/plugs/buffer_limiter_test.exs
index efa2be64ff..62df1bf895 100644
--- a/test/logflare_web/controllers/plugs/buffer_limiter_test.exs
+++ b/test/logflare_web/controllers/plugs/buffer_limiter_test.exs
@@ -187,6 +187,40 @@ defmodule LogflareWeb.Plugs.BufferLimiterTest do
                     %{source_id: ^source_id, source_token: ^source_token}}
   end
 
+  describe "single-tenant ClickHouse system default" do
+    TestUtils.setup_single_tenant(backend_type: :clickhouse)
+
+    test "uses the consolidated default cache", %{
+      conn: conn,
+      source: source
+    } do
+      backend = Backends.get_default_backend(%Logflare.User{id: source.user_id})
+
+      over_limit = Backends.max_buffer_queue_len() + 1
+
+      Logflare.PubSubRates.Cache.cache_buffers(source.id, nil, %{
+        Node.self() => %{len: over_limit, queues: [{{source.id, nil, self()}, over_limit}]}
+      })
+
+      conn = conn |> assign(:source, source) |> BufferLimiter.call(%{})
+      refute conn.halted
+
+      assert Backends.system_default_ingest_queue_key(source) == {:consolidated, backend.id}
+
+      Logflare.PubSubRates.Cache.cache_buffers(:consolidated, backend.id, %{
+        Node.self() => %{
+          len: over_limit,
+          queues: [{{:consolidated, backend.id, self()}, over_limit}]
+        }
+      })
+
+      conn = conn |> recycle() |> assign(:source, source) |> BufferLimiter.call(%{})
+
+      assert conn.halted
+      assert json_response(conn, 429)
+    end
+  end
+
   describe "default ingest feature" do
     setup do
       user = insert(:user)
@@ -511,14 +545,14 @@ defmodule LogflareWeb.Plugs.BufferLimiterTest do
       end
 
       # Fill CH backend queue over the limit
-      clickhouse_queue_key = {source.id, clickhouse_backend.id, self()}
+      clickhouse_queue_key = {:consolidated, clickhouse_backend.id, self()}
       IngestEventQueue.upsert_tid(clickhouse_queue_key)
 
       fill_queue(clickhouse_queue_key, source)
 
       # Cache buffer stats for both backends
       Backends.cache_local_buffer_lens(source.id, nil)
-      Backends.cache_local_buffer_lens(source.id, clickhouse_backend.id)
+      Backends.cache_local_buffer_lens(:consolidated, clickhouse_backend.id)
 
       conn =
         conn
diff --git a/test/support/test_utils.ex b/test/support/test_utils.ex
index c7d7a7ccd8..d6cb5a992b 100644
--- a/test/support/test_utils.ex
+++ b/test/support/test_utils.ex
@@ -26,6 +26,8 @@ defmodule Logflare.TestUtils do
   Options:
   - :seed_user - boolean - enable to seed default plan and user
   - :supabase_mode - enable to seed supabase data
+  - :backend_type - the selected single-tenant backend
+  - :clickhouse_backend_adapter_opts - ClickHouse connection options
   """
   defmacro setup_single_tenant(opts \\ []) do
     opts =
@@ -34,7 +36,12 @@ defmodule Logflare.TestUtils do
         supabase_mode: false,
         bigquery_project_id: random_string(),
         backend_type: :bigquery,
-        pg_schema: nil
+        pg_schema: nil,
+        clickhouse_backend_adapter_opts: [
+          url: "http://localhost:8123",
+          database: "logflare_test",
+          port: 8123
+        ]
       })
 
     quote do
@@ -42,8 +49,18 @@ defmodule Logflare.TestUtils do
 
       setup do
         initial_single_tenant = Application.get_env(:logflare, :single_tenant)
+
+        initial_single_tenant_backend =
+          Application.get_env(:logflare, :single_tenant_backend)
+
         Application.put_env(:logflare, :single_tenant, true)
 
+        Application.put_env(
+          :logflare,
+          :single_tenant_backend,
+          unquote(opts.backend_type)
+        )
+
         if unquote(opts.seed_user) do
           {:ok, _} = SingleTenant.create_default_plan()
           {:ok, _user} = SingleTenant.create_default_user()
@@ -67,6 +84,13 @@ defmodule Logflare.TestUtils do
 
         on_exit(fn ->
           Application.put_env(:logflare, :single_tenant, initial_single_tenant)
+
+          Application.put_env(
+            :logflare,
+            :single_tenant_backend,
+            initial_single_tenant_backend
+          )
+
           Application.put_env(:logflare, :public_access_token, initial_public_access_token)
           Application.put_env(:logflare, :private_access_token, initial_private_access_token)
         end)
@@ -115,6 +139,21 @@ defmodule Logflare.TestUtils do
     end
   end
 
+  defp setup_single_tenant_backend(%{
+         backend_type: :clickhouse,
+         clickhouse_backend_adapter_opts: opts
+       }) do
+    quote do
+      setup do
+        previous = Application.get_env(:logflare, :clickhouse_backend_adapter)
+        Application.put_env(:logflare, :clickhouse_backend_adapter, unquote(opts))
+
+        on_exit(fn -> Application.put_env(:logflare, :clickhouse_backend_adapter, previous) end)
+        :ok
+      end
+    end
+  end
+
   def default_bq_schema, do: SchemaBuilder.initial_table_schema()
 
   def build_bq_schema(params) do

From 3bdeabc04a29abcb5f76d091463c62e8f5209bf8 Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Mon, 24 Aug 2026 09:56:11 +1000
Subject: [PATCH 02/17] fix: non_negative_integer backend_id for connection
 manager

---
 lib/logflare/backends/adaptor/clickhouse_adaptor.ex   |  4 ++--
 .../backends/adaptor/clickhouse_adaptor_test.exs      | 11 +++++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/lib/logflare/backends/adaptor/clickhouse_adaptor.ex b/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
index 5f6d484efb..e1bd34ebde 100644
--- a/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
+++ b/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
@@ -1622,7 +1622,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor do
   @spec maybe_start_query_connection_manager(pid() | nil, non_neg_integer(), String.t() | nil) ::
           :ok | {:error, term()}
   defp maybe_start_query_connection_manager(nil, backend_id, label)
-       when is_pos_integer(backend_id) do
+       when is_non_negative_integer(backend_id) do
     backend = Backends.Cache.get_backend(backend_id)
 
     with child_spec <- ConnectionManager.child_spec(backend, label),
@@ -1650,7 +1650,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor do
     end
   end
 
-  defp maybe_start_query_connection_manager(_pid, _backend_id, _label), do: :ok
+  defp maybe_start_query_connection_manager(pid, _backend_id, _label) when is_pid(pid), do: :ok
 
   @spec ensure_pool_and_notify(Backend.t(), String.t() | nil) :: :ok | {:error, term()}
   defp ensure_pool_and_notify(%Backend{} = backend, label) do
diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
index 35c6ed3ba1..e05b81e930 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
@@ -99,6 +99,17 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       assert is_integer(bytes)
     end
 
+    test "can execute queries for the single tenant backend", %{backend: backend} do
+      backend = %{backend | id: 0}
+      refute Backends.Cache.get_backend(backend.id)
+      Logflare.ContextCache.update(Backends, :get_backend, [backend.id], backend)
+
+      assert {:ok, {[%{"test" => 1}], bytes}} =
+               ClickHouseAdaptor.execute_ch_query(backend, "SELECT 1 as test")
+
+      assert is_integer(bytes)
+    end
+
     test "handles query errors", %{backend: backend} do
       result =
         ClickHouseAdaptor.execute_ch_query(backend, "INVALID SQL QUERY")

From 6f3e0839b741c6675aa122378ef22e8f1c8aa493 Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Mon, 24 Aug 2026 10:28:19 +1000
Subject: [PATCH 03/17] fix: start FinchDefaultHttp1 pool in single-tenant
 ClickHouse & postgres modes

Move FinchDefaultHttp1 pool to base_finch_pools
---
 lib/logflare/networking.ex        | 4 ++--
 test/logflare/networking_test.exs | 8 +++++---
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/lib/logflare/networking.ex b/lib/logflare/networking.ex
index f0039502b0..23a4bdf48a 100644
--- a/lib/logflare/networking.ex
+++ b/lib/logflare/networking.ex
@@ -50,8 +50,6 @@ defmodule Logflare.Networking do
     [
       # Finch connection pools, using http2
       {Finch, name: Logflare.FinchGoth, pools: %{default: [protocols: [:http2], count: 1]}},
-      {Finch,
-       name: Logflare.FinchDefaultHttp1, pools: %{default: [protocols: [:http1], size: 50]}},
       {Finch,
        name: Logflare.FinchIngest,
        pools: %{
@@ -150,6 +148,8 @@ defmodule Logflare.Networking do
     base = System.schedulers_online()
 
     [
+      {Finch,
+       name: Logflare.FinchDefaultHttp1, pools: %{default: [protocols: [:http1], size: 50]}},
       {Finch,
        name: Logflare.FinchClickHouseIngest,
        pools: %{
diff --git a/test/logflare/networking_test.exs b/test/logflare/networking_test.exs
index 9b73a96cd8..1e192c254f 100644
--- a/test/logflare/networking_test.exs
+++ b/test/logflare/networking_test.exs
@@ -32,10 +32,10 @@ defmodule Logflare.NetworkingTest do
     test "returns bigquery, clickhouse, and spool connection pools" do
       assert finch_names() == [
                Logflare.FinchGoth,
-               Logflare.FinchDefaultHttp1,
                Logflare.FinchIngest,
                Logflare.FinchQuery,
                Logflare.FinchDefault,
+               Logflare.FinchDefaultHttp1,
                Logflare.FinchSpoolS3,
                Logflare.FinchSpoolSQS,
                Logflare.FinchClickHouseIngest,
@@ -64,13 +64,14 @@ defmodule Logflare.NetworkingTest do
         |> Map.put(:default, protocols: [:http1])
 
       assert [
+               {Finch, [name: Logflare.FinchDefault, pools: datadog_pools]},
                {Finch,
                 name: Logflare.FinchDefaultHttp1,
                 pools: %{default: [protocols: [:http1], size: 50]}},
                {Finch,
                 [
-                  name: Logflare.FinchDefault,
-                  pools: datadog_pools
+                  name: Logflare.FinchDefaultHttp1,
+                  pools: %{default: [protocols: [:http1], size: 50]}
                 ]},
                {Finch,
                 name: Logflare.FinchSpoolS3,
@@ -207,6 +208,7 @@ defmodule Logflare.NetworkingTest do
     test "excludes BigQuery and gRPC connection pools" do
       assert finch_names() == [
                Logflare.FinchDefault,
+               Logflare.FinchDefaultHttp1,
                Logflare.FinchClickHouseIngest,
                Logflare.FinchClickHouseAsyncIngest
              ]

From 970ca56882d1f558ece285a5302064670967eb17 Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Wed, 16 Sep 2026 00:15:00 +0000
Subject: [PATCH 04/17] fix: validate single-tenant backend configuration

---
 config/runtime.exs                   |   8 ++
 lib/logflare/single_tenant.ex        |  14 +---
 test/config/runtime_test.exs         | 111 +++++++++++++++++++++++++++
 test/logflare/single_tenant_test.exs |  16 ++++
 4 files changed, 139 insertions(+), 10 deletions(-)
 create mode 100644 test/config/runtime_test.exs

diff --git a/config/runtime.exs b/config/runtime.exs
index acfe3090dc..8f6573f0bd 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -392,11 +392,19 @@ socket_options_for_url = fn
 end
 
 single_tenant? = Env.get_boolean("LOGFLARE_SINGLE_TENANT")
+bigquery_service_account = System.get_env("GOOGLE_SERVICE_ACCOUNT")
 postgres_backend_url = System.get_env("POSTGRES_BACKEND_URL")
 clickhouse_backend_url = System.get_env("CLICKHOUSE_BACKEND_URL")
 
 backend_url_set? = fn url -> is_binary(url) and String.trim(url) != "" end
 
+if Enum.count(
+     [bigquery_service_account, postgres_backend_url, clickhouse_backend_url],
+     backend_url_set?
+   ) > 1 do
+  raise "Only one of GOOGLE_SERVICE_ACCOUNT, POSTGRES_BACKEND_URL, or CLICKHOUSE_BACKEND_URL may be configured"
+end
+
 single_tenant_backend =
   cond do
     single_tenant? and backend_url_set?.(postgres_backend_url) -> :postgres
diff --git a/lib/logflare/single_tenant.ex b/lib/logflare/single_tenant.ex
index 384780c454..50ce95fbf5 100644
--- a/lib/logflare/single_tenant.ex
+++ b/lib/logflare/single_tenant.ex
@@ -421,26 +421,20 @@ defmodule Logflare.SingleTenant do
   """
   @spec backend_type :: backend_type()
   def backend_type do
-    Application.get_env(:logflare, :single_tenant_backend) || :bigquery
+    Application.fetch_env!(:logflare, :single_tenant_backend)
   end
 
   @doc "Returns true if BigQuery is selected in single-tenant mode"
   @spec bigquery_backend? :: boolean()
-  def bigquery_backend? do
-    selected_backend?(:bigquery)
-  end
+  def bigquery_backend?, do: selected_backend?(:bigquery)
 
   @doc "Returns true if PostgreSQL is selected in single-tenant mode"
   @spec postgres_backend? :: boolean()
-  def postgres_backend? do
-    selected_backend?(:postgres)
-  end
+  def postgres_backend?, do: selected_backend?(:postgres)
 
   @doc "Returns true if ClickHouse is selected in single-tenant mode"
   @spec clickhouse_backend? :: boolean()
-  def clickhouse_backend? do
-    selected_backend?(:clickhouse)
-  end
+  def clickhouse_backend?, do: selected_backend?(:clickhouse)
 
   def supabase_mode_source_schemas_updated? do
     user = get_default_user()
diff --git a/test/config/runtime_test.exs b/test/config/runtime_test.exs
new file mode 100644
index 0000000000..43a7357806
--- /dev/null
+++ b/test/config/runtime_test.exs
@@ -0,0 +1,111 @@
+defmodule Logflare.RuntimeConfigTest do
+  use ExUnit.Case, async: false
+
+  alias Logflare.SingleTenant
+
+  @backend_env_vars [
+    "GOOGLE_SERVICE_ACCOUNT",
+    "POSTGRES_BACKEND_URL",
+    "CLICKHOUSE_BACKEND_URL"
+  ]
+  @clickhouse_backend_url "http://localhost:8123/logflare"
+  @postgres_backend_url "postgresql://postgres:postgres@localhost/logflare"
+
+  setup do
+    previous_values =
+      ["LOGFLARE_SINGLE_TENANT" | @backend_env_vars]
+      |> Map.new(&{&1, System.get_env(&1)})
+
+    previous_backend = Application.fetch_env(:logflare, :single_tenant_backend)
+
+    System.put_env("LOGFLARE_SINGLE_TENANT", "true")
+    Enum.each(@backend_env_vars, &System.delete_env/1)
+
+    on_exit(fn ->
+      case previous_backend do
+        {:ok, backend} -> Application.put_env(:logflare, :single_tenant_backend, backend)
+        :error -> Application.delete_env(:logflare, :single_tenant_backend)
+      end
+
+      Enum.each(previous_values, fn
+        {name, nil} -> System.delete_env(name)
+        {name, value} -> System.put_env(name, value)
+      end)
+    end)
+  end
+
+  test "defaults the single-tenant backend to BigQuery when no backend URL is configured" do
+    assert runtime_backend_type() == :bigquery
+  end
+
+  test "selects the configured backend" do
+    for {env, value, expected_backend} <- [
+          {"GOOGLE_SERVICE_ACCOUNT", "service-account", :bigquery},
+          {"POSTGRES_BACKEND_URL", @postgres_backend_url, :postgres},
+          {"CLICKHOUSE_BACKEND_URL", @clickhouse_backend_url, :clickhouse}
+        ] do
+      System.put_env(env, value)
+
+      assert runtime_backend_type() == expected_backend
+
+      System.delete_env(env)
+    end
+  end
+
+  test "ignores blank backend URLs" do
+    System.put_env("POSTGRES_BACKEND_URL", " ")
+    System.put_env("CLICKHOUSE_BACKEND_URL", "\t")
+
+    assert runtime_backend_type() == :bigquery
+  end
+
+  test "rejects multiple backend URL configurations" do
+    System.put_env("POSTGRES_BACKEND_URL", @postgres_backend_url)
+    System.put_env("CLICKHOUSE_BACKEND_URL", @clickhouse_backend_url)
+
+    assert_raise RuntimeError,
+                 "Only one of GOOGLE_SERVICE_ACCOUNT, POSTGRES_BACKEND_URL, or CLICKHOUSE_BACKEND_URL may be configured",
+                 &runtime_config/0
+  end
+
+  test "rejects BigQuery with another backend configuration" do
+    System.put_env("GOOGLE_SERVICE_ACCOUNT", "service-account")
+
+    for {backend_env, value} <- [
+          {"POSTGRES_BACKEND_URL", @postgres_backend_url},
+          {"CLICKHOUSE_BACKEND_URL", @clickhouse_backend_url}
+        ] do
+      System.put_env(backend_env, value)
+
+      assert_raise RuntimeError,
+                   "Only one of GOOGLE_SERVICE_ACCOUNT, POSTGRES_BACKEND_URL, or CLICKHOUSE_BACKEND_URL may be configured",
+                   &runtime_config/0
+
+      System.delete_env(backend_env)
+    end
+  end
+
+  test "defaults to BigQuery outside single-tenant mode" do
+    System.put_env("LOGFLARE_SINGLE_TENANT", "false")
+
+    for {configured_env, value, unconfigured_env} <- [
+          {"POSTGRES_BACKEND_URL", @postgres_backend_url, "CLICKHOUSE_BACKEND_URL"},
+          {"CLICKHOUSE_BACKEND_URL", @clickhouse_backend_url, "POSTGRES_BACKEND_URL"}
+        ] do
+      System.put_env(configured_env, value)
+      System.delete_env(unconfigured_env)
+
+      assert runtime_backend_type() == :bigquery
+    end
+  end
+
+  defp runtime_backend_type do
+    backend_type = get_in(runtime_config(), [:logflare, :single_tenant_backend])
+    Application.put_env(:logflare, :single_tenant_backend, backend_type)
+    SingleTenant.backend_type()
+  end
+
+  defp runtime_config do
+    Config.Reader.read!("config/runtime.exs", env: :test)
+  end
+end
diff --git a/test/logflare/single_tenant_test.exs b/test/logflare/single_tenant_test.exs
index e415bad97a..cb46ed3e76 100644
--- a/test/logflare/single_tenant_test.exs
+++ b/test/logflare/single_tenant_test.exs
@@ -179,6 +179,22 @@ defmodule Logflare.SingleTenantTest do
     assert Backends.bigquery_default_backend?()
   end
 
+  test "backend_type/0 requires runtime configuration" do
+    previous_backend = Application.fetch_env(:logflare, :single_tenant_backend)
+    Application.delete_env(:logflare, :single_tenant_backend)
+
+    on_exit(fn ->
+      case previous_backend do
+        {:ok, backend} -> Application.put_env(:logflare, :single_tenant_backend, backend)
+        :error -> Application.delete_env(:logflare, :single_tenant_backend)
+      end
+    end)
+
+    assert_raise ArgumentError, ~r/could not fetch application environment/, fn ->
+      SingleTenant.backend_type()
+    end
+  end
+
   describe "supabase_mode=true using Big Query" do
     TestUtils.setup_single_tenant(seed_user: true, supabase_mode: true)
 

From 493169cce21f7d271d3de35641be2f77df086b5d Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Thu, 17 Sep 2026 02:16:09 +0000
Subject: [PATCH 05/17] refactor: use start_supervised for Clickhouse tests

---
 .../single_tenant_ingestion_test.exs             | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs
index e7dffb6f70..5a135bfd62 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs
@@ -29,22 +29,12 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.SingleTenantIngestionTest
     backend = Logflare.Backends.get_default_backend(user)
 
     start_supervised!(AllLogsLogged)
-    {:ok, connection_manager_pid} = ConnectionManager.start_link(backend)
-    {:ok, supervisor_pid} = ClickHouseAdaptor.start_link(backend)
+    start_supervised!({ConnectionManager, backend})
+    start_supervised!({ClickHouseAdaptor, backend})
 
     cleanup_single_tenant_tables(backend)
 
-    on_exit(fn ->
-      cleanup_single_tenant_tables(backend)
-
-      if Process.alive?(supervisor_pid) do
-        Process.exit(supervisor_pid, :shutdown)
-      end
-
-      if Process.alive?(connection_manager_pid) do
-        Process.exit(connection_manager_pid, :shutdown)
-      end
-    end)
+    on_exit(fn -> cleanup_single_tenant_tables(backend) end)
 
     [source: source, backend: backend]
   end

From 3f81e614d803d219e29437fc0f0ddf61e203a564 Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Thu, 17 Sep 2026 17:29:43 +1000
Subject: [PATCH 06/17] style: @doc ingest_queue_key

---
 lib/logflare/backends.ex | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/lib/logflare/backends.ex b/lib/logflare/backends.ex
index ab8586a852..8b3bb6ae95 100644
--- a/lib/logflare/backends.ex
+++ b/lib/logflare/backends.ex
@@ -60,7 +60,12 @@ defmodule Logflare.Backends do
   def bigquery_default_backend?,
     do: not SingleTenant.single_tenant?() or SingleTenant.bigquery_backend?()
 
-  @doc false
+  @doc """
+  Returns queue key used to buffer events for a source and backend.
+
+  Consolidated backends share a queue keyed by backend ID, other backends scope
+  to source and backend.
+  """
   @spec ingest_queue_key(Source.t(), Backend.t() | nil) :: ingest_queue_key()
   def ingest_queue_key(%Source{}, %Backend{consolidated_ingest?: true, id: backend_id}) do
     {:consolidated, backend_id}
@@ -72,7 +77,12 @@ defmodule Logflare.Backends do
 
   def ingest_queue_key(%Source{id: source_id}, nil), do: {source_id, nil}
 
-  @doc false
+  @doc """
+  Returns the queue key used to buffer events for a source's system default backend.
+
+  In single-tenant ClickHouse deployments, uses `ingest_queue_key/2` with the
+  source user's default backend. Otherwise, returns `{source_id, nil}`.
+  """
   @spec system_default_ingest_queue_key(Source.t()) :: ingest_queue_key()
   def system_default_ingest_queue_key(%Source{} = source) do
     ingest_queue_key(source, lookup_system_default_backend(source))

From 053609415756df10fb5037c40d302e402c620dc2 Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Thu, 17 Sep 2026 17:48:45 +1000
Subject: [PATCH 07/17] feat: allow configuring single-tenant ClickHouse table
 suffix

---
 DEVELOPMENT.md                                |  1 +
 config/runtime.exs                            |  1 +
 .../backends/adaptor/clickhouse_adaptor.ex    | 11 +++---
 test/config/runtime_test.exs                  | 11 +++++-
 .../adaptor/clickhouse_adaptor_test.exs       | 34 ++++++++++++++++---
 5 files changed, 49 insertions(+), 9 deletions(-)

diff --git a/DEVELOPMENT.md b/DEVELOPMENT.md
index e800bad3e6..1551c7403f 100644
--- a/DEVELOPMENT.md
+++ b/DEVELOPMENT.md
@@ -95,6 +95,7 @@ make start.st.ch
 
 - `CLICKHOUSE_BACKEND_URL` - the ClickHouse HTTP connection URL, including the database name
 - `CLICKHOUSE_BACKEND_POOL_SIZE` - optional connection pool size
+- `LOGFLARE_CLICKHOUSE_TABLE_SUFFIX` - suffix for the single-tenant `otel_logs`, `otel_metrics`, and `otel_traces` tables (defaults to `default`)
 - `LOGFLARE_PUBLIC_ACCESS_TOKEN` and `LOGFLARE_PRIVATE_ACCESS_TOKEN` - local API tokens
 
 PostgreSQL is still required for Logflare application data. ClickHouse becomes the default
diff --git a/config/runtime.exs b/config/runtime.exs
index 8f6573f0bd..397d55b3fc 100644
--- a/config/runtime.exs
+++ b/config/runtime.exs
@@ -136,6 +136,7 @@ config :logflare,
          recaptcha_secret: System.get_env("LOGFLARE_RECAPTCHA_SECRET"),
          config_cat_sdk_key: System.get_env("LOGFLARE_CONFIG_CAT_SDK_KEY"),
          single_tenant: Env.get_boolean("LOGFLARE_SINGLE_TENANT"),
+         clickhouse_table_suffix: System.get_env("LOGFLARE_CLICKHOUSE_TABLE_SUFFIX", "default"),
          supabase_mode: Env.get_boolean("LOGFLARE_SUPABASE_MODE"),
          unsafe_disable_ssrf_s3_endpoint_check:
            Env.get_boolean("LOGFLARE_UNSAFE_DISABLE_SSRF_S3_ENDPOINT_CHECK"),
diff --git a/lib/logflare/backends/adaptor/clickhouse_adaptor.ex b/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
index e1bd34ebde..a7a328d1b0 100644
--- a/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
+++ b/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
@@ -707,17 +707,17 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor do
   - `:metric` -> `otel_metrics_<token>`
   - `:trace`  -> `otel_traces_<token>`
 
-  Single-tenant defaults use `single_tenant` suffix in place of `<token>`
+  Single-tenant defaults use the configured table suffix in place of `_<token>`.
   """
   @spec clickhouse_ingest_table_name(Backend.t(), TypeDetection.event_type()) :: String.t()
   def clickhouse_ingest_table_name(%Backend{single_tenant_default?: true}, :log),
-    do: "otel_logs_single_tenant"
+    do: "otel_logs_#{clickhouse_table_suffix()}"
 
   def clickhouse_ingest_table_name(%Backend{single_tenant_default?: true}, :metric),
-    do: "otel_metrics_single_tenant"
+    do: "otel_metrics_#{clickhouse_table_suffix()}"
 
   def clickhouse_ingest_table_name(%Backend{single_tenant_default?: true}, :trace),
-    do: "otel_traces_single_tenant"
+    do: "otel_traces_#{clickhouse_table_suffix()}"
 
   def clickhouse_ingest_table_name(%Backend{} = backend, :log),
     do: build_otel_table_name(backend, "otel_logs")
@@ -728,6 +728,9 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor do
   def clickhouse_ingest_table_name(%Backend{} = backend, :trace),
     do: build_otel_table_name(backend, "otel_traces")
 
+  @spec clickhouse_table_suffix() :: String.t()
+  defp clickhouse_table_suffix, do: Application.fetch_env!(:logflare, :clickhouse_table_suffix)
+
   @spec build_otel_table_name(Backend.t(), String.t()) :: String.t()
   defp build_otel_table_name(%Backend{token: token}, prefix) do
     token_str = String.replace(token, "-", "_")
diff --git a/test/config/runtime_test.exs b/test/config/runtime_test.exs
index 43a7357806..bd914e6c49 100644
--- a/test/config/runtime_test.exs
+++ b/test/config/runtime_test.exs
@@ -6,7 +6,8 @@ defmodule Logflare.RuntimeConfigTest do
   @backend_env_vars [
     "GOOGLE_SERVICE_ACCOUNT",
     "POSTGRES_BACKEND_URL",
-    "CLICKHOUSE_BACKEND_URL"
+    "CLICKHOUSE_BACKEND_URL",
+    "LOGFLARE_CLICKHOUSE_TABLE_SUFFIX"
   ]
   @clickhouse_backend_url "http://localhost:8123/logflare"
   @postgres_backend_url "postgresql://postgres:postgres@localhost/logflare"
@@ -38,6 +39,14 @@ defmodule Logflare.RuntimeConfigTest do
     assert runtime_backend_type() == :bigquery
   end
 
+  test "configures the ClickHouse table suffix" do
+    assert get_in(runtime_config(), [:logflare, :clickhouse_table_suffix]) == "default"
+
+    System.put_env("LOGFLARE_CLICKHOUSE_TABLE_SUFFIX", "custom")
+
+    assert get_in(runtime_config(), [:logflare, :clickhouse_table_suffix]) == "custom"
+  end
+
   test "selects the configured backend" do
     for {env, value, expected_backend} <- [
           {"GOOGLE_SERVICE_ACCOUNT", "service-account", :bigquery},
diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
index e05b81e930..f2db030d34 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
@@ -27,6 +27,16 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     setup do
       insert(:plan, name: "Free")
 
+      previous_table_suffix = Application.fetch_env(:logflare, :clickhouse_table_suffix)
+      Application.put_env(:logflare, :clickhouse_table_suffix, "default")
+
+      on_exit(fn ->
+        case previous_table_suffix do
+          {:ok, suffix} -> Application.put_env(:logflare, :clickhouse_table_suffix, suffix)
+          :error -> Application.delete_env(:logflare, :clickhouse_table_suffix)
+        end
+      end)
+
       {source, backend} = setup_clickhouse_test()
 
       stringified_backend_token =
@@ -59,17 +69,33 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
                "otel_traces_#{stringified_backend_token}"
     end
 
-    test "uses fixed table names for the synthetic single-tenant backend", %{backend: backend} do
+    test "uses default table names for the synthetic single-tenant backend", %{backend: backend} do
+      backend = %{backend | id: 0, single_tenant_default?: true}
+
+      assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :log) ==
+               "otel_logs_default"
+
+      assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :metric) ==
+               "otel_metrics_default"
+
+      assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :trace) ==
+               "otel_traces_default"
+    end
+
+    test "uses the configured suffix for the synthetic single-tenant backend", %{
+      backend: backend
+    } do
+      Application.put_env(:logflare, :clickhouse_table_suffix, "custom")
       backend = %{backend | id: 0, single_tenant_default?: true}
 
       assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :log) ==
-               "otel_logs_single_tenant"
+               "otel_logs_custom"
 
       assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :metric) ==
-               "otel_metrics_single_tenant"
+               "otel_metrics_custom"
 
       assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :trace) ==
-               "otel_traces_single_tenant"
+               "otel_traces_custom"
     end
   end
 

From 1ae67abf42e7c75f8e8a5ae028fda5341554b785 Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Thu, 17 Sep 2026 23:11:28 +0000
Subject: [PATCH 08/17] fix: leave single-tenant ClickHouse token unset

---
 lib/logflare/backends.ex             | 1 -
 test/logflare/single_tenant_test.exs | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/logflare/backends.ex b/lib/logflare/backends.ex
index 8b3bb6ae95..1b69ff8339 100644
--- a/lib/logflare/backends.ex
+++ b/lib/logflare/backends.ex
@@ -292,7 +292,6 @@ defmodule Logflare.Backends do
   defp single_tenant_clickhouse_backend(%User{} = user) do
     %Backend{
       id: @single_tenant_clickhouse_backend_id,
-      token: "00000000-0000-0000-0000-000000000000",
       type: :clickhouse,
       config: Map.new(SingleTenant.clickhouse_backend_adapter_opts()),
       user_id: user.id,
diff --git a/test/logflare/single_tenant_test.exs b/test/logflare/single_tenant_test.exs
index cb46ed3e76..e189003280 100644
--- a/test/logflare/single_tenant_test.exs
+++ b/test/logflare/single_tenant_test.exs
@@ -317,7 +317,7 @@ defmodule Logflare.SingleTenantTest do
 
       assert %Backend{
                id: 0,
-               token: "00000000-0000-0000-0000-000000000000",
+               token: nil,
                user_id: user_id,
                type: :clickhouse,
                single_tenant_default?: true,

From 9c4ceabb131234ec80be69d09d58cecc875417cd Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Thu, 17 Sep 2026 23:28:12 +0000
Subject: [PATCH 09/17] refactor: move single-tenant backend helpers to
 SingleTenant

---
 lib/logflare/backends.ex                      | 35 +++----------------
 .../backends/consolidated_sup_worker.ex       |  3 +-
 lib/logflare/single_tenant.ex                 | 23 ++++++++++++
 .../backends/consolidated_sup_worker_test.exs |  3 +-
 test/logflare/single_tenant_test.exs          | 28 +++++++++++++++
 5 files changed, 59 insertions(+), 33 deletions(-)

diff --git a/lib/logflare/backends.ex b/lib/logflare/backends.ex
index 1b69ff8339..3cbb650a90 100644
--- a/lib/logflare/backends.ex
+++ b/lib/logflare/backends.ex
@@ -42,7 +42,6 @@ defmodule Logflare.Backends do
   @max_pending_buffer_len_per_queue IngestEventQueue.max_queue_size()
   @default_source_sup_start_timeout :timer.seconds(30)
   @max_pipeline_swap_delay_ms 5_000
-  @single_tenant_clickhouse_backend_id 0
 
   @type one_or_list_or_nil :: Backend.t() | [Backend.t()] | nil
   @type ingest_queue_key ::
@@ -85,7 +84,7 @@ defmodule Logflare.Backends do
   """
   @spec system_default_ingest_queue_key(Source.t()) :: ingest_queue_key()
   def system_default_ingest_queue_key(%Source{} = source) do
-    ingest_queue_key(source, lookup_system_default_backend(source))
+    ingest_queue_key(source, SingleTenant.lookup_system_default_backend(source))
   end
 
   @doc """
@@ -281,31 +280,11 @@ defmodule Logflare.Backends do
     end
   end
 
-  @spec get_single_tenant_default_backend() :: Backend.t() | nil
-  def get_single_tenant_default_backend do
-    user = SingleTenant.get_default_user()
-
-    if SingleTenant.clickhouse_backend?() && user,
-      do: single_tenant_clickhouse_backend(user)
-  end
-
-  defp single_tenant_clickhouse_backend(%User{} = user) do
-    %Backend{
-      id: @single_tenant_clickhouse_backend_id,
-      type: :clickhouse,
-      config: Map.new(SingleTenant.clickhouse_backend_adapter_opts()),
-      user_id: user.id,
-      name: "Default ClickHouse backend",
-      consolidated_ingest?: true,
-      single_tenant_default?: true
-    }
-  end
-
   @spec get_default_backend(User.t()) :: Backend.t() | nil
   def get_default_backend(%User{} = user) do
     cond do
       SingleTenant.clickhouse_backend?() ->
-        single_tenant_clickhouse_backend(user)
+        SingleTenant.get_default_clickhouse_backend(user)
 
       SingleTenant.postgres_backend?() ->
         opts = SingleTenant.postgres_backend_adapter_opts()
@@ -596,7 +575,7 @@ defmodule Logflare.Backends do
   Retrieves a Backend by id.
   """
   @spec get_backend(integer()) :: Backend.t() | nil
-  def get_backend(@single_tenant_clickhouse_backend_id), do: get_single_tenant_default_backend()
+  def get_backend(0), do: SingleTenant.get_default_clickhouse_backend()
 
   def get_backend(id) do
     backend = Repo.get(Backend, id)
@@ -1051,17 +1030,11 @@ defmodule Logflare.Backends do
   defp dispatch_to_backends(source, nil, log_events) do
     backends = __MODULE__.Cache.list_backends(source_id: source.id)
 
-    for backend <- [lookup_system_default_backend(source) | backends] do
+    for backend <- [SingleTenant.lookup_system_default_backend(source) | backends] do
       dispatch_to_default_backend(source, backend, log_events)
     end
   end
 
-  defp lookup_system_default_backend(%Source{user_id: user_id}) do
-    if SingleTenant.clickhouse_backend?() do
-      get_default_backend(%User{id: user_id})
-    end
-  end
-
   @spec dispatch_to_default_backend(
           source :: Source.t(),
           backend :: Backend.t() | nil,
diff --git a/lib/logflare/backends/consolidated_sup_worker.ex b/lib/logflare/backends/consolidated_sup_worker.ex
index 8dce0357c7..b1d7d1496e 100644
--- a/lib/logflare/backends/consolidated_sup_worker.ex
+++ b/lib/logflare/backends/consolidated_sup_worker.ex
@@ -14,6 +14,7 @@ defmodule Logflare.Backends.ConsolidatedSupWorker do
   alias Logflare.Backends
   alias Logflare.Backends.Adaptor
   alias Logflare.Backends.ConsolidatedSup
+  alias Logflare.SingleTenant
 
   @default_interval 30_000
 
@@ -53,7 +54,7 @@ defmodule Logflare.Backends.ConsolidatedSupWorker do
 
   defp list_expected_backend_ids do
     default_backend_ids =
-      case Backends.get_single_tenant_default_backend() do
+      case SingleTenant.get_default_clickhouse_backend() do
         nil -> []
         backend -> [backend.id]
       end
diff --git a/lib/logflare/single_tenant.ex b/lib/logflare/single_tenant.ex
index 50ce95fbf5..92cb784d1c 100644
--- a/lib/logflare/single_tenant.ex
+++ b/lib/logflare/single_tenant.ex
@@ -111,6 +111,29 @@ defmodule Logflare.SingleTenant do
     |> Backends.get_default_backend()
   end
 
+  @doc "Returns the synthetic ClickHouse backend when selected and the user exists."
+  @spec get_default_clickhouse_backend(User.t() | nil) :: Backend.t() | nil
+  @spec get_default_clickhouse_backend() :: Backend.t() | nil
+  def get_default_clickhouse_backend(user \\ get_default_user()) do
+    if clickhouse_backend?() && user do
+      %Backend{
+        id: 0,
+        type: :clickhouse,
+        config: Map.new(clickhouse_backend_adapter_opts()),
+        user_id: user.id,
+        name: "Default ClickHouse backend",
+        consolidated_ingest?: true,
+        single_tenant_default?: true
+      }
+    end
+  end
+
+  @doc "Returns a source's synthetic ClickHouse backend, or nil for legacy per-source defaults."
+  @spec lookup_system_default_backend(Source.t()) :: Backend.t() | nil
+  def lookup_system_default_backend(%Source{user_id: user_id}) do
+    get_default_clickhouse_backend(%User{id: user_id})
+  end
+
   @doc """
   Creates an enterprise user
   """
diff --git a/test/logflare/backends/consolidated_sup_worker_test.exs b/test/logflare/backends/consolidated_sup_worker_test.exs
index 6066be676a..6966b7a596 100644
--- a/test/logflare/backends/consolidated_sup_worker_test.exs
+++ b/test/logflare/backends/consolidated_sup_worker_test.exs
@@ -4,6 +4,7 @@ defmodule Logflare.Backends.ConsolidatedSupWorkerTest do
   alias Logflare.Backends
   alias Logflare.Backends.ConsolidatedSup
   alias Logflare.Backends.ConsolidatedSupWorker
+  alias Logflare.SingleTenant
 
   describe "ConsolidatedSupWorker" do
     setup do
@@ -83,7 +84,7 @@ defmodule Logflare.Backends.ConsolidatedSupWorkerTest do
     TestUtils.setup_single_tenant(seed_user: true, backend_type: :clickhouse)
 
     test "starts the synthetic consolidated backend without sources or rules" do
-      backend = Backends.get_single_tenant_default_backend()
+      backend = SingleTenant.get_default_clickhouse_backend()
       assert backend.id == 0
 
       on_exit(fn -> ConsolidatedSup.stop_pipeline(backend.id) end)
diff --git a/test/logflare/single_tenant_test.exs b/test/logflare/single_tenant_test.exs
index e189003280..b1f4fc958c 100644
--- a/test/logflare/single_tenant_test.exs
+++ b/test/logflare/single_tenant_test.exs
@@ -113,6 +113,8 @@ defmodule Logflare.SingleTenantTest do
       assert {:ok, user} = SingleTenant.create_default_user()
       assert %Backend{type: :bigquery} = SingleTenant.get_default_backend()
       assert %Backend{type: :bigquery} = Backends.get_default_backend(user)
+      assert SingleTenant.get_default_clickhouse_backend() == nil
+      assert SingleTenant.lookup_system_default_backend(%Source{user_id: user.id}) == nil
     end
 
     test "single_tenant? returns true when in single tenant mode" do
@@ -242,6 +244,14 @@ defmodule Logflare.SingleTenantTest do
   describe "single tenant mode using Postgres" do
     TestUtils.setup_single_tenant(backend_type: :postgres)
 
+    test "does not return a synthetic ClickHouse backend" do
+      assert {:ok, _plan} = SingleTenant.create_default_plan()
+      assert {:ok, user} = SingleTenant.create_default_user()
+
+      assert SingleTenant.get_default_clickhouse_backend() == nil
+      assert SingleTenant.lookup_system_default_backend(%Source{user_id: user.id}) == nil
+    end
+
     test "create_default_plan/0 creates default enterprise plan if not present" do
       assert {:ok, plan} = SingleTenant.create_default_plan()
       assert plan.name == "Enterprise"
@@ -297,6 +307,24 @@ defmodule Logflare.SingleTenantTest do
       ]
     )
 
+    test "returns nil before the default user exists" do
+      assert SingleTenant.get_default_user() == nil
+      assert SingleTenant.get_default_clickhouse_backend() == nil
+      assert Backends.get_backend(0) == nil
+    end
+
+    test "source lookup uses the source owner rather than the default user" do
+      assert {:ok, _plan} = SingleTenant.create_default_plan()
+      assert {:ok, default_user} = SingleTenant.create_default_user()
+      source = %Source{user_id: default_user.id + 1}
+
+      assert %Backend{id: 0, token: nil, user_id: user_id, consolidated_ingest?: true} =
+               SingleTenant.lookup_system_default_backend(source)
+
+      assert user_id == source.user_id
+      assert SingleTenant.get_default_clickhouse_backend().user_id == default_user.id
+    end
+
     test "startup uses a synthetic backend and skips BigQuery side effects" do
       reject(BigQueryAdaptor, :create_managed_service_accounts, 0)
       reject(BigQueryAdaptor, :update_iam_policy, 0)

From 7967ec436a2bcf7d85b6c7d35f9e3d4f03c1fa2e Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Thu, 17 Sep 2026 23:41:14 +0000
Subject: [PATCH 10/17] refactor: single tenant helpers into SingleTenant

---
 lib/logflare/single_tenant.ex        | 20 ++++++++++++++++----
 test/logflare/single_tenant_test.exs |  6 ++++++
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/lib/logflare/single_tenant.ex b/lib/logflare/single_tenant.ex
index 92cb784d1c..372349b3ed 100644
--- a/lib/logflare/single_tenant.ex
+++ b/lib/logflare/single_tenant.ex
@@ -111,16 +111,28 @@ defmodule Logflare.SingleTenant do
     |> Backends.get_default_backend()
   end
 
-  @doc "Returns the synthetic ClickHouse backend when selected and the user exists."
+  @doc """
+  Builds the synthetic backend when ClickHouse is selected in single-tenant mode.
+
+  Uses the supplied user's ID, looking up the default user only when omitted.
+  Returns nil when ClickHouse is not selected or the user is nil.
+
+  Backend ID `0` is reserved for this synthetic backend and identifies its
+  consolidated pipeline and ingestion queues. The backend is not persisted.
+  """
   @spec get_default_clickhouse_backend(User.t() | nil) :: Backend.t() | nil
   @spec get_default_clickhouse_backend() :: Backend.t() | nil
-  def get_default_clickhouse_backend(user \\ get_default_user()) do
-    if clickhouse_backend?() && user do
+  def get_default_clickhouse_backend(user \\ get_default_user())
+
+  def get_default_clickhouse_backend(nil), do: nil
+
+  def get_default_clickhouse_backend(%User{id: user_id}) do
+    if clickhouse_backend?() do
       %Backend{
         id: 0,
         type: :clickhouse,
         config: Map.new(clickhouse_backend_adapter_opts()),
-        user_id: user.id,
+        user_id: user_id,
         name: "Default ClickHouse backend",
         consolidated_ingest?: true,
         single_tenant_default?: true
diff --git a/test/logflare/single_tenant_test.exs b/test/logflare/single_tenant_test.exs
index b1f4fc958c..2735cb3da7 100644
--- a/test/logflare/single_tenant_test.exs
+++ b/test/logflare/single_tenant_test.exs
@@ -313,6 +313,12 @@ defmodule Logflare.SingleTenantTest do
       assert Backends.get_backend(0) == nil
     end
 
+    test "rejects plain maps in place of user structs" do
+      assert_raise FunctionClauseError, fn ->
+        apply(SingleTenant, :get_default_clickhouse_backend, [%{id: 123}])
+      end
+    end
+
     test "source lookup uses the source owner rather than the default user" do
       assert {:ok, _plan} = SingleTenant.create_default_plan()
       assert {:ok, default_user} = SingleTenant.create_default_user()

From fdb4554658511bc2ce2c3097ac973f4026b138a1 Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Fri, 18 Sep 2026 00:24:20 +0000
Subject: [PATCH 11/17] fix: resolve single-tenant ClickHouse CI failures

---
 .reach.baseline.json                                        | 6 +++---
 .../clickhouse_adaptor/single_tenant_ingestion_test.exs     | 1 +
 test/logflare/networking_test.exs                           | 3 ++-
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/.reach.baseline.json b/.reach.baseline.json
index 01c1591ebe..b2d31227b6 100644
--- a/.reach.baseline.json
+++ b/.reach.baseline.json
@@ -781,10 +781,10 @@
     {
       "source": "smells",
       "kind": "redundant_computation",
-      "fingerprint": "sha256:def6b8334cb5e0de59e58e669a16f009f819b7a3f280e81d65b6cf75216d3646",
-      "message": "Logflare.Auth.list_valid_access_tokens called twice with same args (line 138 and 168)",
+      "fingerprint": "sha256:9a7130a7a6e263eec866c2d02c31a837cb2fc4f7ed89ceac5eda162e7d76570e",
+      "message": "Logflare.Auth.list_valid_access_tokens called twice with same args (line 187 and 217)",
       "file": "lib/logflare/single_tenant.ex",
-      "line": 168
+      "line": 217
     },
     {
       "source": "smells",
diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs
index 5a135bfd62..33f9fd76ef 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs
@@ -80,6 +80,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.SingleTenantIngestionTest
       end
     after
       if stop_manager? and Process.alive?(manager_pid) do
+        ConnectionManager.refresh_pool(backend)
         GenServer.stop(manager_pid)
       end
     end
diff --git a/test/logflare/networking_test.exs b/test/logflare/networking_test.exs
index 1e192c254f..0e0bf44968 100644
--- a/test/logflare/networking_test.exs
+++ b/test/logflare/networking_test.exs
@@ -210,7 +210,8 @@ defmodule Logflare.NetworkingTest do
                Logflare.FinchDefault,
                Logflare.FinchDefaultHttp1,
                Logflare.FinchClickHouseIngest,
-               Logflare.FinchClickHouseAsyncIngest
+               Logflare.FinchClickHouseAsyncIngest,
+               Logflare.FinchS3
              ]
 
       refute Enum.any?(Networking.pools(), &match?({Logflare.Networking.GrpcPool, _}, &1))

From 580f5d0974f75b9c8f612be07c5ce9e381b77d86 Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Fri, 18 Sep 2026 01:46:38 +0000
Subject: [PATCH 12/17] refactor: use helper to identify single-tenant
 clickhouse backend

---
 .reach.baseline.json                          |  6 ++---
 .../backends/adaptor/clickhouse_adaptor.ex    | 26 +++++++------------
 lib/logflare/backends/backend.ex              |  1 -
 lib/logflare/single_tenant.ex                 | 17 +++++++++---
 .../adaptor/clickhouse_adaptor_test.exs       | 25 ++++++++++++++++--
 test/logflare/backends/backend_test.exs       | 16 ------------
 test/logflare/single_tenant_test.exs          |  4 ++-
 7 files changed, 53 insertions(+), 42 deletions(-)

diff --git a/.reach.baseline.json b/.reach.baseline.json
index b2d31227b6..f0fc868731 100644
--- a/.reach.baseline.json
+++ b/.reach.baseline.json
@@ -781,10 +781,10 @@
     {
       "source": "smells",
       "kind": "redundant_computation",
-      "fingerprint": "sha256:9a7130a7a6e263eec866c2d02c31a837cb2fc4f7ed89ceac5eda162e7d76570e",
-      "message": "Logflare.Auth.list_valid_access_tokens called twice with same args (line 187 and 217)",
+      "fingerprint": "sha256:7f50270eeee917c359a84869adaf9f5e5a01a3e4e7853c4dd9111f8159773b82",
+      "message": "Logflare.Auth.list_valid_access_tokens called twice with same args (line 188 and 218)",
       "file": "lib/logflare/single_tenant.ex",
-      "line": 217
+      "line": 218
     },
     {
       "source": "smells",
diff --git a/lib/logflare/backends/adaptor/clickhouse_adaptor.ex b/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
index a7a328d1b0..2d73f250e2 100644
--- a/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
+++ b/lib/logflare/backends/adaptor/clickhouse_adaptor.ex
@@ -36,6 +36,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor do
   alias Logflare.Backends.QueryError
   alias Logflare.LogEvent
   alias Logflare.LogEvent.TypeDetection
+  alias Logflare.SingleTenant
   alias Logflare.Sources.Source
   alias Logflare.Sql.DialectTransformer.ClickHouse, as: ClickHouseSqlTransformer
   alias Mint.Types, as: MintTypes
@@ -710,23 +711,16 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor do
   Single-tenant defaults use the configured table suffix in place of `_<token>`.
   """
   @spec clickhouse_ingest_table_name(Backend.t(), TypeDetection.event_type()) :: String.t()
-  def clickhouse_ingest_table_name(%Backend{single_tenant_default?: true}, :log),
-    do: "otel_logs_#{clickhouse_table_suffix()}"
+  def clickhouse_ingest_table_name(%Backend{} = backend, event_type)
+      when event_type in [:log, :metric, :trace] do
+    prefix = "otel_" <> to_string(event_type) <> "s"
 
-  def clickhouse_ingest_table_name(%Backend{single_tenant_default?: true}, :metric),
-    do: "otel_metrics_#{clickhouse_table_suffix()}"
-
-  def clickhouse_ingest_table_name(%Backend{single_tenant_default?: true}, :trace),
-    do: "otel_traces_#{clickhouse_table_suffix()}"
-
-  def clickhouse_ingest_table_name(%Backend{} = backend, :log),
-    do: build_otel_table_name(backend, "otel_logs")
-
-  def clickhouse_ingest_table_name(%Backend{} = backend, :metric),
-    do: build_otel_table_name(backend, "otel_metrics")
-
-  def clickhouse_ingest_table_name(%Backend{} = backend, :trace),
-    do: build_otel_table_name(backend, "otel_traces")
+    if SingleTenant.default_clickhouse_backend?(backend) do
+      prefix <> "_" <> clickhouse_table_suffix()
+    else
+      build_otel_table_name(backend, prefix)
+    end
+  end
 
   @spec clickhouse_table_suffix() :: String.t()
   defp clickhouse_table_suffix, do: Application.fetch_env!(:logflare, :clickhouse_table_suffix)
diff --git a/lib/logflare/backends/backend.ex b/lib/logflare/backends/backend.ex
index b95d3a0e24..6736e39a15 100644
--- a/lib/logflare/backends/backend.ex
+++ b/lib/logflare/backends/backend.ex
@@ -72,7 +72,6 @@ defmodule Logflare.Backends.Backend do
     field :metadata, :map
     field :default_ingest?, :boolean, source: :default_ingest, default: false
     field :enabled, :boolean, default: true
-    field :single_tenant_default?, :boolean, virtual: true, default: false
 
     belongs_to :user, User
 
diff --git a/lib/logflare/single_tenant.ex b/lib/logflare/single_tenant.ex
index 372349b3ed..8682f56db0 100644
--- a/lib/logflare/single_tenant.ex
+++ b/lib/logflare/single_tenant.ex
@@ -19,6 +19,8 @@ defmodule Logflare.SingleTenant do
   alias Logflare.SourceSchemas
   require Logger
 
+  @single_tenant_clickhouse_backend_id 0
+
   @user_attrs %{
     name: "default",
     email: "default@logflare.app",
@@ -129,13 +131,12 @@ defmodule Logflare.SingleTenant do
   def get_default_clickhouse_backend(%User{id: user_id}) do
     if clickhouse_backend?() do
       %Backend{
-        id: 0,
+        id: @single_tenant_clickhouse_backend_id,
         type: :clickhouse,
         config: Map.new(clickhouse_backend_adapter_opts()),
         user_id: user_id,
         name: "Default ClickHouse backend",
-        consolidated_ingest?: true,
-        single_tenant_default?: true
+        consolidated_ingest?: true
       }
     end
   end
@@ -471,6 +472,16 @@ defmodule Logflare.SingleTenant do
   @spec clickhouse_backend? :: boolean()
   def clickhouse_backend?, do: selected_backend?(:clickhouse)
 
+  @doc "Returns whether this is the default backend in a single-tenant ClickHouse mode."
+  @spec default_clickhouse_backend?(Backend.t()) :: boolean()
+  def default_clickhouse_backend?(%Backend{
+        id: @single_tenant_clickhouse_backend_id,
+        type: :clickhouse
+      }),
+      do: clickhouse_backend?()
+
+  def default_clickhouse_backend?(%Backend{}), do: false
+
   def supabase_mode_source_schemas_updated? do
     user = get_default_user()
 
diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
index f2db030d34..3e18c19527 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
@@ -24,6 +24,8 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
   doctest ClickHouseAdaptor
 
   describe "table name generation" do
+    TestUtils.setup_single_tenant(backend_type: :clickhouse)
+
     setup do
       insert(:plan, name: "Free")
 
@@ -70,7 +72,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     end
 
     test "uses default table names for the synthetic single-tenant backend", %{backend: backend} do
-      backend = %{backend | id: 0, single_tenant_default?: true}
+      backend = %{backend | id: 0, token: nil}
 
       assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :log) ==
                "otel_logs_default"
@@ -86,7 +88,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       backend: backend
     } do
       Application.put_env(:logflare, :clickhouse_table_suffix, "custom")
-      backend = %{backend | id: 0, single_tenant_default?: true}
+      backend = %{backend | id: 0, token: nil}
 
       assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :log) ==
                "otel_logs_custom"
@@ -97,6 +99,25 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :trace) ==
                "otel_traces_custom"
     end
+
+    test "does not use the configured suffix outside single-tenant ClickHouse mode", %{
+      backend: backend,
+      stringified_backend_token: token
+    } do
+      backend = %{backend | id: 0}
+
+      for {single_tenant, backend_type} <- [
+            {false, :clickhouse},
+            {true, :postgres},
+            {true, :bigquery}
+          ] do
+        Application.put_env(:logflare, :single_tenant, single_tenant)
+        Application.put_env(:logflare, :single_tenant_backend, backend_type)
+
+        assert ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :log) ==
+                 "otel_logs_#{token}"
+      end
+    end
   end
 
   describe "connection and basic functionality" do
diff --git a/test/logflare/backends/backend_test.exs b/test/logflare/backends/backend_test.exs
index 1f8efbb040..e87d6b32c3 100644
--- a/test/logflare/backends/backend_test.exs
+++ b/test/logflare/backends/backend_test.exs
@@ -139,21 +139,5 @@ defmodule Logflare.Backends.BackendTest do
                "Backend type webhook does not support default ingest"
              ]
     end
-
-    test "does not allow the single-tenant default marker changeset", %{
-      user: user
-    } do
-      attrs = %{
-        name: "Test ClickHouse Backend",
-        type: :clickhouse,
-        config: %{url: "http://localhost:8123", database: "default", port: 8123},
-        single_tenant_default?: true
-      }
-
-      changeset = Backend.changeset(Ecto.build_assoc(user, :backends), attrs)
-
-      assert changeset.valid?
-      refute get_field(changeset, :single_tenant_default?)
-    end
   end
 end
diff --git a/test/logflare/single_tenant_test.exs b/test/logflare/single_tenant_test.exs
index 2735cb3da7..f256e2db17 100644
--- a/test/logflare/single_tenant_test.exs
+++ b/test/logflare/single_tenant_test.exs
@@ -354,7 +354,6 @@ defmodule Logflare.SingleTenantTest do
                token: nil,
                user_id: user_id,
                type: :clickhouse,
-               single_tenant_default?: true,
                config: %{
                  url: "http://localhost:8123",
                  database: "logflare_test",
@@ -362,6 +361,9 @@ defmodule Logflare.SingleTenantTest do
                }
              } = backend = Backends.get_default_backend(user)
 
+      assert SingleTenant.default_clickhouse_backend?(backend)
+      refute SingleTenant.default_clickhouse_backend?(%{backend | id: 1})
+      refute SingleTenant.default_clickhouse_backend?(%{backend | type: :postgres})
       assert user.id == user_id
       assert SingleTenant.get_default_backend() == backend
       assert Backends.get_backend(0) == backend

From f404490c5fdd6127e74977e4319de80259a2df64 Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Fri, 18 Sep 2026 04:38:28 +0000
Subject: [PATCH 13/17] refactor: startup hooks into SystemBackend behaviour

---
 lib/logflare/application.ex                   | 15 ++----
 .../backends/adaptor/bigquery_adaptor.ex      | 46 +++++++++++++++++++
 lib/logflare/backends/system_backend.ex       | 45 ++++++++++++++++++
 lib/logflare/sources/source/supervisor.ex     | 32 +------------
 .../backends/bigquery_adaptor_test.exs        | 39 ++++++++++++++++
 .../logflare/backends/system_backend_test.exs | 44 ++++++++++++++++++
 test/logflare/single_tenant_test.exs          | 34 +++++++++++---
 7 files changed, 207 insertions(+), 48 deletions(-)
 create mode 100644 lib/logflare/backends/system_backend.ex
 create mode 100644 test/logflare/backends/system_backend_test.exs

diff --git a/lib/logflare/application.ex b/lib/logflare/application.ex
index a08ee5acf2..7ee7c8fa83 100644
--- a/lib/logflare/application.ex
+++ b/lib/logflare/application.ex
@@ -5,11 +5,11 @@ defmodule Logflare.Application do
   require Logger
 
   alias Logflare.Alerting.AlertSchedulerWorker
-  alias Logflare.Backends
   alias Logflare.Networking
   alias Logflare.Backends.Adaptor.BigQueryAdaptor
   alias Logflare.Backends.Spool.Health, as: SpoolHealth
   alias Logflare.Backends.Spool.SpoolAck
+  alias Logflare.Backends.SystemBackend
   alias Logflare.Backends.UserMonitoring
   alias Logflare.ContextCache
   alias Logflare.Logs
@@ -235,10 +235,7 @@ defmodule Logflare.Application do
   def startup_tasks do
     Logger.info("Executing startup tasks")
 
-    if Backends.bigquery_default_backend?() do
-      BigQueryAdaptor.create_managed_service_accounts()
-      BigQueryAdaptor.update_iam_policy()
-    end
+    SystemBackend.on_system_start()
 
     if SingleTenant.single_tenant?() do
       Logger.info("Ensuring single tenant user is seeded...")
@@ -253,13 +250,7 @@ defmodule Logflare.Application do
       SingleTenant.create_supabase_endpoints()
       SingleTenant.ensure_supabase_sources_started()
 
-      if Backends.bigquery_default_backend?() do
-        # buffer time for all sources to init and create tables
-        # in case of latency.
-        :timer.sleep(3_000)
-
-        SingleTenant.update_supabase_source_schemas()
-      end
+      SystemBackend.on_supabase_start()
     end
 
     # Schedule all alerts immediately on startup
diff --git a/lib/logflare/backends/adaptor/bigquery_adaptor.ex b/lib/logflare/backends/adaptor/bigquery_adaptor.ex
index 929effdd83..9d9bf26f0a 100644
--- a/lib/logflare/backends/adaptor/bigquery_adaptor.ex
+++ b/lib/logflare/backends/adaptor/bigquery_adaptor.ex
@@ -2,6 +2,7 @@ defmodule Logflare.Backends.Adaptor.BigQueryAdaptor do
   @moduledoc false
 
   @behaviour Logflare.Backends.Adaptor
+  @behaviour Logflare.Backends.SystemBackend
 
   use Supervisor
 
@@ -28,15 +29,19 @@ defmodule Logflare.Backends.Adaptor.BigQueryAdaptor do
   alias Logflare.BqRepo
   alias Logflare.Endpoints.EndpointQuery
   alias Logflare.Google
+  alias Logflare.Google.BigQuery
   alias Logflare.Google.BigQuery.EventUtils
   alias Logflare.Google.BigQuery.GCPConfig
   alias Logflare.Google.BigQuery.GenUtils
   alias Logflare.Google.CloudResourceManager
+  alias Logflare.SingleTenant
   alias Logflare.Sources
+  alias Logflare.Sources.Source
   alias Logflare.Sources.Source.BigQuery.Pipeline
   alias Logflare.Sources.Source.BigQuery.Schema
   alias Logflare.User
   alias Logflare.Users
+  alias Logflare.Utils.Tasks
   alias Model.QueryParameter, as: Param
   alias Model.QueryParameterType, as: Type
   alias Model.QueryParameterValue, as: Value
@@ -47,6 +52,47 @@ defmodule Logflare.Backends.Adaptor.BigQueryAdaptor do
   @search_query_timeout_ms 60_000
   @endpoint_query_timeout_ms 60_000
 
+  @impl Logflare.Backends.SystemBackend
+  @spec on_system_start() :: :ok
+  def on_system_start do
+    create_managed_service_accounts()
+    update_iam_policy()
+    :ok
+  end
+
+  @impl Logflare.Backends.SystemBackend
+  @spec on_source_start(Source.t()) :: :ok
+  def on_source_start(%Source{token: source_token}) do
+    %{
+      user_id: user_id,
+      bigquery_table_ttl: bigquery_table_ttl,
+      bigquery_project_id: bigquery_project_id,
+      bigquery_dataset_location: bigquery_dataset_location,
+      bigquery_dataset_id: bigquery_dataset_id
+    } = GenUtils.get_bq_user_info(source_token)
+
+    Tasks.start_child(fn ->
+      BigQuery.init_table!(
+        user_id,
+        source_token,
+        bigquery_project_id,
+        bigquery_table_ttl,
+        bigquery_dataset_location,
+        bigquery_dataset_id
+      )
+    end)
+
+    :ok
+  end
+
+  @impl Logflare.Backends.SystemBackend
+  @spec on_supabase_start() :: :ok
+  def on_supabase_start do
+    :timer.sleep(3_000)
+    SingleTenant.update_supabase_source_schemas()
+    :ok
+  end
+
   @impl Logflare.Backends.Adaptor
   def start_link({source, backend} = source_backend) do
     Supervisor.start_link(__MODULE__, source_backend,
diff --git a/lib/logflare/backends/system_backend.ex b/lib/logflare/backends/system_backend.ex
new file mode 100644
index 0000000000..ad5807b2ce
--- /dev/null
+++ b/lib/logflare/backends/system_backend.ex
@@ -0,0 +1,45 @@
+defmodule Logflare.Backends.SystemBackend do
+  @moduledoc """
+  Lifecycle hooks for the system backend, distinct from user-configured backends.
+
+  Hooks are optional; adaptors without a hook require no additional setup.
+  """
+
+  alias Logflare.Backends.Adaptor
+  alias Logflare.Backends.Backend
+  alias Logflare.SingleTenant
+  alias Logflare.Sources.Source
+
+  @doc "Runs before single-tenant users and sources are seeded."
+  @callback on_system_start() :: :ok
+
+  @doc "Runs after a source supervisor starts."
+  @callback on_source_start(Source.t()) :: :ok
+
+  @doc "Runs after Supabase sources and endpoints are seeded and source startup is requested."
+  @callback on_supabase_start() :: :ok
+
+  @optional_callbacks on_system_start: 0, on_source_start: 1, on_supabase_start: 0
+
+  @spec on_system_start() :: :ok
+  def on_system_start, do: invoke(:on_system_start, [])
+
+  @spec on_source_start(Source.t()) :: :ok
+  def on_source_start(%Source{} = source), do: invoke(:on_source_start, [source])
+
+  @spec on_supabase_start() :: :ok
+  def on_supabase_start, do: invoke(:on_supabase_start, [])
+
+  @spec invoke(atom(), list()) :: :ok
+  defp invoke(callback, args) do
+    type = if SingleTenant.single_tenant?(), do: SingleTenant.backend_type(), else: :bigquery
+    adaptor = Adaptor.get_adaptor(%Backend{type: type})
+    Code.ensure_loaded!(adaptor)
+
+    if function_exported?(adaptor, callback, length(args)) do
+      apply(adaptor, callback, args)
+    else
+      :ok
+    end
+  end
+end
diff --git a/lib/logflare/sources/source/supervisor.ex b/lib/logflare/sources/source/supervisor.ex
index 11a709a09e..b6b13f8087 100644
--- a/lib/logflare/sources/source/supervisor.ex
+++ b/lib/logflare/sources/source/supervisor.ex
@@ -5,6 +5,7 @@ defmodule Logflare.Sources.Source.Supervisor do
   use GenServer
 
   alias Logflare.Backends
+  alias Logflare.Backends.SystemBackend
   alias Logflare.ContextCache
   alias Logflare.Google.BigQuery
   alias Logflare.Repo
@@ -12,7 +13,6 @@ defmodule Logflare.Sources.Source.Supervisor do
   alias Logflare.Sources
   alias Logflare.Sources.Counters
   alias Logflare.Sources.Source
-  alias Logflare.Utils.Tasks
 
   require Logger
 
@@ -96,7 +96,6 @@ defmodule Logflare.Sources.Source.Supervisor do
   ## Public Functions
 
   def start_source(source_token) when is_atom(source_token) do
-    # Calling this server doing boot times out due to dealing with bigquery in init_table()
     GenServer.abcast(__MODULE__, {:create, source_token})
 
     {:ok, source_token}
@@ -139,7 +138,7 @@ defmodule Logflare.Sources.Source.Supervisor do
 
   defp create_source(%Source{} = source) do
     with {:ok, _pid} = res <- do_start_source_sup(source),
-         :ok <- maybe_init_table(source.token) do
+         :ok <- SystemBackend.on_source_start(source) do
       res
     else
       {:error, :already_started} = err ->
@@ -160,10 +159,6 @@ defmodule Logflare.Sources.Source.Supervisor do
     end
   end
 
-  defp maybe_init_table(source_token) do
-    if Backends.bigquery_default_backend?(), do: init_table(source_token), else: :ok
-  end
-
   @spec ensure_started(Source.t()) :: :ok
   def ensure_started(%Source{token: source_token} = source) do
     # Check if already running
@@ -179,29 +174,6 @@ defmodule Logflare.Sources.Source.Supervisor do
     :ok
   end
 
-  def init_table(source_token) do
-    %{
-      user_id: user_id,
-      bigquery_table_ttl: bigquery_table_ttl,
-      bigquery_project_id: bigquery_project_id,
-      bigquery_dataset_location: bigquery_dataset_location,
-      bigquery_dataset_id: bigquery_dataset_id
-    } = BigQuery.GenUtils.get_bq_user_info(source_token)
-
-    Tasks.start_child(fn ->
-      BigQuery.init_table!(
-        user_id,
-        source_token,
-        bigquery_project_id,
-        bigquery_table_ttl,
-        bigquery_dataset_location,
-        bigquery_dataset_id
-      )
-    end)
-
-    :ok
-  end
-
   defp do_start_source_sup(source) do
     with :ok <- Backends.start_source_sup(source) do
       do_lookup(source)
diff --git a/test/logflare/backends/bigquery_adaptor_test.exs b/test/logflare/backends/bigquery_adaptor_test.exs
index 802b7f84ee..a95c1812c5 100644
--- a/test/logflare/backends/bigquery_adaptor_test.exs
+++ b/test/logflare/backends/bigquery_adaptor_test.exs
@@ -10,6 +10,8 @@ defmodule Logflare.Backends.BigQueryAdaptorTest do
   alias Logflare.Backends.SourceSup
   alias Logflare.Backends.Adaptor.BigQueryAdaptor
   alias Logflare.Backends.Adaptor.QueryResult
+  alias Logflare.Google.CloudResourceManager
+  alias Logflare.SingleTenant
   alias Logflare.SystemMetrics.AllLogsLogged
   alias GoogleApi.CloudResourceManager.V1.Model
 
@@ -498,6 +500,37 @@ defmodule Logflare.Backends.BigQueryAdaptorTest do
       assert_receive {:created, "logflare-managed-1"}, 1000
     end
 
+    test "on_system_start/0 provisions missing accounts and updates IAM policy" do
+      expect(GoogleApi.IAM.V1.Api.Projects, :iam_projects_service_accounts_list, fn
+        _conn, "projects/" <> project_id, _opts ->
+          {:ok,
+           %{
+             accounts: [
+               %GoogleApi.IAM.V1.Model.ServiceAccount{
+                 email: "logflare-managed-0@#{project_id}.iam.gserviceaccount.com",
+                 name:
+                   "projects/#{project_id}/serviceAccounts/logflare-managed-0@#{project_id}.iam.gserviceaccount.com"
+               }
+             ],
+             nextPageToken: nil
+           }}
+      end)
+
+      expect(GoogleApi.IAM.V1.Api.Projects, :iam_projects_service_accounts_create, fn
+        _conn, "projects/" <> project_id, opts ->
+          assert %{accountId: "logflare-managed-1"} = opts[:body]
+
+          {:ok,
+           %GoogleApi.IAM.V1.Model.ServiceAccount{
+             email: "logflare-managed-1@#{project_id}.iam.gserviceaccount.com"
+           }}
+      end)
+
+      expect(CloudResourceManager, :set_iam_policy, fn [async: false] -> :ok end)
+
+      assert :ok = BigQueryAdaptor.on_system_start()
+    end
+
     test "update_iam_policy/0" do
       pid = self()
       # Mock IAM API calls for listing existing service accounts
@@ -537,6 +570,12 @@ defmodule Logflare.Backends.BigQueryAdaptorTest do
     end
   end
 
+  test "on_supabase_start/0 updates source schemas" do
+    expect(SingleTenant, :update_supabase_source_schemas, fn -> :ok end)
+
+    assert :ok = BigQueryAdaptor.on_supabase_start()
+  end
+
   describe "managed service accounts is disabled" do
     setup do
       original_pool_size =
diff --git a/test/logflare/backends/system_backend_test.exs b/test/logflare/backends/system_backend_test.exs
new file mode 100644
index 0000000000..90ce6a740b
--- /dev/null
+++ b/test/logflare/backends/system_backend_test.exs
@@ -0,0 +1,44 @@
+defmodule Logflare.Backends.SystemBackendTest do
+  use Logflare.DataCase, async: false
+
+  alias Logflare.Backends.Adaptor.BigQueryAdaptor
+  alias Logflare.Backends.SystemBackend
+  alias Logflare.Sources.Source
+
+  TestUtils.setup_single_tenant(backend_type: :bigquery)
+
+  test "dispatches lifecycle hooks to the single-tenant BigQuery adaptor" do
+    assert_bigquery_hooks_dispatched(build(:source))
+  end
+
+  test "multi-tenant deployments use BigQuery regardless of the single-tenant selection" do
+    Application.put_env(:logflare, :single_tenant, false)
+    Application.put_env(:logflare, :single_tenant_backend, :clickhouse)
+    assert_bigquery_hooks_dispatched(build(:source))
+  end
+
+  test "PostgreSQL and ClickHouse do not run BigQuery setup" do
+    reject(BigQueryAdaptor, :on_system_start, 0)
+    reject(BigQueryAdaptor, :on_source_start, 1)
+    reject(BigQueryAdaptor, :on_supabase_start, 0)
+
+    for type <- [:postgres, :clickhouse] do
+      Application.put_env(:logflare, :single_tenant_backend, type)
+
+      assert :ok = SystemBackend.on_system_start()
+      assert :ok = SystemBackend.on_source_start(build(:source))
+      assert :ok = SystemBackend.on_supabase_start()
+    end
+  end
+
+  @spec assert_bigquery_hooks_dispatched(Source.t()) :: :ok
+  defp assert_bigquery_hooks_dispatched(source) do
+    expect(BigQueryAdaptor, :on_system_start, fn -> :ok end)
+    expect(BigQueryAdaptor, :on_source_start, fn ^source -> :ok end)
+    expect(BigQueryAdaptor, :on_supabase_start, fn -> :ok end)
+
+    assert :ok = SystemBackend.on_system_start()
+    assert :ok = SystemBackend.on_source_start(source)
+    assert :ok = SystemBackend.on_supabase_start()
+  end
+end
diff --git a/test/logflare/single_tenant_test.exs b/test/logflare/single_tenant_test.exs
index f256e2db17..4c511503e0 100644
--- a/test/logflare/single_tenant_test.exs
+++ b/test/logflare/single_tenant_test.exs
@@ -122,13 +122,39 @@ defmodule Logflare.SingleTenantTest do
     end
 
     test "Logflare.Application.startup_tasks/0 should insert plan and user" do
-      expect(BigQueryAdaptor, :update_iam_policy, fn -> :ok end)
+      expect(BigQueryAdaptor, :on_system_start, fn ->
+        assert SingleTenant.get_default_user() == nil
+        :ok
+      end)
 
       Logflare.Application.startup_tasks()
 
       assert [_] = Billing.list_plans()
       assert 1 = Users.count_users()
     end
+
+    test "startup invokes Supabase setup after sources and endpoints are seeded" do
+      previous_supabase_mode = Application.get_env(:logflare, :supabase_mode)
+      Application.put_env(:logflare, :supabase_mode, true)
+      on_exit(fn -> Application.put_env(:logflare, :supabase_mode, previous_supabase_mode) end)
+
+      expect(BigQueryAdaptor, :on_system_start, fn -> :ok end)
+      expect(SingleTenant, :create_supabase_sources, fn -> send(self(), :sources_seeded) end)
+      expect(SingleTenant, :create_supabase_endpoints, fn -> send(self(), :endpoints_seeded) end)
+
+      expect(SingleTenant, :ensure_supabase_sources_started, fn ->
+        send(self(), :sources_started)
+      end)
+
+      expect(BigQueryAdaptor, :on_supabase_start, fn ->
+        assert_received :sources_seeded
+        assert_received :endpoints_seeded
+        assert_received :sources_started
+        :ok
+      end)
+
+      Logflare.Application.startup_tasks()
+    end
   end
 
   describe ":postgres_backend_url" do
@@ -331,11 +357,7 @@ defmodule Logflare.SingleTenantTest do
       assert SingleTenant.get_default_clickhouse_backend().user_id == default_user.id
     end
 
-    test "startup uses a synthetic backend and skips BigQuery side effects" do
-      reject(BigQueryAdaptor, :create_managed_service_accounts, 0)
-      reject(BigQueryAdaptor, :update_iam_policy, 0)
-      reject(Schema, :update, 3)
-
+    test "startup uses a synthetic ClickHouse backend" do
       expect(SingleTenant, :create_supabase_sources, fn -> {:ok, []} end)
       expect(SingleTenant, :create_supabase_endpoints, fn -> {:ok, []} end)
       expect(SingleTenant, :ensure_supabase_sources_started, fn -> :ok end)

From 54a37a8ba633835e20eccbbf27416af36786841a Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Mon, 28 Sep 2026 04:27:36 +0000
Subject: [PATCH 14/17] fix: avoid duplicate FinchDefaultHttp1 pool

---
 lib/logflare/networking.ex        |  2 --
 test/logflare/networking_test.exs | 15 ++++++---------
 2 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/lib/logflare/networking.ex b/lib/logflare/networking.ex
index 23a4bdf48a..9c8fab3f60 100644
--- a/lib/logflare/networking.ex
+++ b/lib/logflare/networking.ex
@@ -29,8 +29,6 @@ defmodule Logflare.Networking do
 
   defp base_finch_pools_with_default do
     [
-      {Finch,
-       name: Logflare.FinchDefaultHttp1, pools: %{default: [protocols: [:http1], size: 50]}},
       {Finch,
        name: Logflare.FinchDefault,
        pools:
diff --git a/test/logflare/networking_test.exs b/test/logflare/networking_test.exs
index 0e0bf44968..86d025c0e1 100644
--- a/test/logflare/networking_test.exs
+++ b/test/logflare/networking_test.exs
@@ -35,9 +35,9 @@ defmodule Logflare.NetworkingTest do
                Logflare.FinchIngest,
                Logflare.FinchQuery,
                Logflare.FinchDefault,
-               Logflare.FinchDefaultHttp1,
                Logflare.FinchSpoolS3,
                Logflare.FinchSpoolSQS,
+               Logflare.FinchDefaultHttp1,
                Logflare.FinchClickHouseIngest,
                Logflare.FinchClickHouseAsyncIngest,
                Logflare.FinchS3
@@ -65,14 +65,6 @@ defmodule Logflare.NetworkingTest do
 
       assert [
                {Finch, [name: Logflare.FinchDefault, pools: datadog_pools]},
-               {Finch,
-                name: Logflare.FinchDefaultHttp1,
-                pools: %{default: [protocols: [:http1], size: 50]}},
-               {Finch,
-                [
-                  name: Logflare.FinchDefaultHttp1,
-                  pools: %{default: [protocols: [:http1], size: 50]}
-                ]},
                {Finch,
                 name: Logflare.FinchSpoolS3,
                 pools: %{
@@ -83,6 +75,11 @@ defmodule Logflare.NetworkingTest do
                 pools: %{
                   default: _spool_sqs_config
                 }},
+               {Finch,
+                [
+                  name: Logflare.FinchDefaultHttp1,
+                  pools: %{default: [protocols: [:http1], size: 50]}
+                ]},
                {Finch,
                 name: Logflare.FinchClickHouseIngest,
                 pools: %{

From 2af55c9525021aae07604c06b895d64375a633fa Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Mon, 5 Oct 2026 06:59:52 +0000
Subject: [PATCH 15/17] fix(text): clear stale mappings

---
 test/support/data_case.ex | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/test/support/data_case.ex b/test/support/data_case.ex
index 4d86aa2e84..88b1a87e64 100644
--- a/test/support/data_case.ex
+++ b/test/support/data_case.ex
@@ -62,6 +62,8 @@ defmodule Logflare.DataCase do
           # judged against genuinely-still-live state — including other concurrently
           # running tests' own queues_keys — not a mapper this same callback is about
           # to clear out from under them.
+          IngestEventQueue.delete_stale_mappings()
+
           for queues_key <- IngestEventQueue.list_generation_queues_keys(),
               IngestEventQueue.list_queues(queues_key) == [] do
             IngestEventQueue.prune_generations(queues_key)

From e5a64cf7305290958a7be9668c28cf1b88dfa1e4 Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Tue, 6 Oct 2026 10:58:12 +1000
Subject: [PATCH 16/17] test: share ClickHouse test setup and cleanup

---
 .../connection_manager_test.exs               |   7 +-
 .../clickhouse_adaptor/ingester_test.exs      |   4 -
 .../clickhouse_adaptor/pipeline_test.exs      |  13 +-
 .../clickhouse_adaptor/provisioner_test.exs   |  17 +-
 .../single_tenant_ingestion_test.exs          |  47 +--
 .../adaptor/clickhouse_adaptor_test.exs       | 292 ++++++------------
 .../backends/consolidated_sup_test.exs        |  11 +-
 test/logflare/endpoints_test.exs              |   3 +-
 test/logflare/single_tenant_test.exs          |  12 +-
 test/logflare/sql_test.exs                    |   3 +-
 .../controllers/api/query_controller_test.exs |   8 +-
 .../live_views/endpoints_live_test.exs        |   5 +-
 .../live_views/query_live_test.exs            |   2 -
 test/support/data_case.ex                     | 134 ++++----
 test/support/test_utils.ex                    |  31 +-
 15 files changed, 186 insertions(+), 403 deletions(-)

diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor/connection_manager_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor/connection_manager_test.exs
index 16e92e13bf..c5752084f7 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor/connection_manager_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor/connection_manager_test.exs
@@ -285,10 +285,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.ConnectionManagerTest do
   describe "query pool credentials" do
     test "the pool authenticates with the dedicated query user when configured" do
       {_source, backend} =
-        setup_clickhouse_test(
-          config: %{query_user: "ch_reader", query_password: "reader_pa55"},
-          cleanup?: false
-        )
+        setup_clickhouse_test(config: %{query_user: "ch_reader", query_password: "reader_pa55"})
 
       assert {"ch_reader", "reader_pa55"} = start_pool_credentials(backend)
     end
@@ -301,7 +298,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.ConnectionManagerTest do
 
     test "the pool falls back to the default credentials when only query_user is configured" do
       {_source, backend} =
-        setup_clickhouse_test(config: %{query_user: "ch_reader"}, cleanup?: false)
+        setup_clickhouse_test(config: %{query_user: "ch_reader"})
 
       assert {"logflare", "logflare"} = start_pool_credentials(backend)
     end
diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor/ingester_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor/ingester_test.exs
index da1ff2fff4..f76869e05a 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor/ingester_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor/ingester_test.exs
@@ -389,12 +389,8 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.IngesterTest do
       insert(:plan, name: "Free")
       {source, backend} = setup_clickhouse_test()
 
-      {:ok, _supervisor_pid} = ClickHouseAdaptor.start_link(backend)
-
       table_name = ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :log)
 
-      Process.sleep(200)
-
       [source: source, backend: backend, table_name: table_name]
     end
 
diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor/pipeline_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor/pipeline_test.exs
index 3546c42ee6..75fc104fe3 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor/pipeline_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor/pipeline_test.exs
@@ -27,18 +27,11 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.PipelineTest do
     insert(:plan, name: "Free")
 
     {source, backend} = setup_clickhouse_test()
+    drop_clickhouse_tables_on_exit(backend)
 
-    {:ok, supervisor_pid} = ClickHouseAdaptor.start_link(backend)
+    start_supervised!({ClickHouseAdaptor, backend})
 
-    on_exit(fn ->
-      if Process.alive?(supervisor_pid) do
-        Process.exit(supervisor_pid, :shutdown)
-      end
-    end)
-
-    TestUtils.retry_assert(fn ->
-      assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
-    end)
+    assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
 
     context = Pipeline.build_processor_context(backend.id)
 
diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor/provisioner_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor/provisioner_test.exs
index 6fcc3bfcba..fccb2bcc0c 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor/provisioner_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor/provisioner_test.exs
@@ -11,14 +11,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.ProvisionerTest do
     insert(:plan, name: "Free")
 
     {source, backend} = setup_clickhouse_test()
-
-    {:ok, supervisor_pid} = ClickHouseAdaptor.start_link(backend)
-
-    on_exit(fn ->
-      if Process.alive?(supervisor_pid) do
-        Process.exit(supervisor_pid, :shutdown)
-      end
-    end)
+    drop_clickhouse_tables_on_exit(backend)
 
     [source: source, backend: backend]
   end
@@ -94,13 +87,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.ProvisionerTest do
       {_source, read_backend} =
         setup_clickhouse_test(config: %{query_user: "ch_reader", query_password: "reader_pa55"})
 
-      {:ok, adaptor_pid} = ClickHouseAdaptor.start_link(read_backend)
-
-      on_exit(fn ->
-        if Process.alive?(adaptor_pid) do
-          Process.exit(adaptor_pid, :shutdown)
-        end
-      end)
+      drop_clickhouse_tables_on_exit(read_backend)
 
       {:ok, pid} = Provisioner.start_link(read_backend)
       ref = Process.monitor(pid)
diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs
index 33f9fd76ef..f6828c9fae 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor/single_tenant_ingestion_test.exs
@@ -2,24 +2,11 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.SingleTenantIngestionTest
   use Logflare.DataCase, async: false
 
   alias Logflare.Backends.Adaptor.ClickHouseAdaptor
-  alias Logflare.Backends.Adaptor.ClickHouseAdaptor.ConnectionManager
   alias Logflare.Backends.Adaptor.ClickHouseAdaptor.Provisioner
   alias Logflare.SingleTenant
   alias Logflare.SystemMetrics.AllLogsLogged
 
-  TestUtils.setup_single_tenant(
-    backend_type: :clickhouse,
-    seed_user: true,
-    clickhouse_backend_adapter_opts: [
-      url: "http://localhost:8123",
-      database: "logflare_test",
-      username: "logflare",
-      password: "logflare",
-      port: 8123,
-      ingest_pool_size: 5,
-      query_pool_size: 3
-    ]
-  )
+  TestUtils.setup_single_tenant(backend_type: :clickhouse, seed_user: true)
 
   setup do
     insert(:plan, name: "Free")
@@ -28,14 +15,10 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.SingleTenantIngestionTest
     source = insert(:source, user: user)
     backend = Logflare.Backends.get_default_backend(user)
 
+    drop_clickhouse_tables_on_exit(backend)
     start_supervised!(AllLogsLogged)
-    start_supervised!({ConnectionManager, backend})
     start_supervised!({ClickHouseAdaptor, backend})
 
-    cleanup_single_tenant_tables(backend)
-
-    on_exit(fn -> cleanup_single_tenant_tables(backend) end)
-
     [source: source, backend: backend]
   end
 
@@ -61,30 +44,4 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptor.SingleTenantIngestionTest
                )
     end)
   end
-
-  defp cleanup_single_tenant_tables(backend) do
-    {manager_pid, stop_manager?} =
-      case ConnectionManager.start_link(backend) do
-        {:ok, pid} ->
-          Process.unlink(pid)
-          {pid, true}
-
-        {:error, {:already_started, pid}} ->
-          {pid, false}
-      end
-
-    try do
-      for event_type <- [:log, :metric, :trace] do
-        table_name = ClickHouseAdaptor.clickhouse_ingest_table_name(backend, event_type)
-        ClickHouseAdaptor.execute_ch_query(backend, "DROP TABLE IF EXISTS #{table_name}")
-      end
-    after
-      if stop_manager? and Process.alive?(manager_pid) do
-        ConnectionManager.refresh_pool(backend)
-        GenServer.stop(manager_pid)
-      end
-    end
-
-    :ok
-  end
 end
diff --git a/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs b/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
index 3e18c19527..7421ca3adc 100644
--- a/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
+++ b/test/logflare/backends/adaptor/clickhouse_adaptor_test.exs
@@ -27,8 +27,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     TestUtils.setup_single_tenant(backend_type: :clickhouse)
 
     setup do
-      insert(:plan, name: "Free")
-
       previous_table_suffix = Application.fetch_env(:logflare, :clickhouse_table_suffix)
       Application.put_env(:logflare, :clickhouse_table_suffix, "default")
 
@@ -39,13 +37,13 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
         end
       end)
 
-      {source, backend} = setup_clickhouse_test()
+      backend = %Backend{type: :clickhouse, token: Ecto.UUID.generate()}
 
       stringified_backend_token =
         backend.token
         |> String.replace("-", "_")
 
-      [source: source, backend: backend, stringified_backend_token: stringified_backend_token]
+      [backend: backend, stringified_backend_token: stringified_backend_token]
     end
 
     test "raises when table name is equal to or exceeds 200 chars",
@@ -126,8 +124,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
 
       {source, backend} = setup_clickhouse_test()
 
-      start_supervised!({ClickHouseAdaptor, backend})
-
       [source: source, backend: backend]
     end
 
@@ -211,7 +207,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     test "describes a real ClickHouse NOT_AN_AGGREGATE error without the physical table", %{
       backend: backend
     } do
-      assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
+      provision_clickhouse_tables!(backend)
       table_name = ClickHouseAdaptor.clickhouse_ingest_table_name(backend, :log)
 
       assert {:error,
@@ -1227,20 +1223,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     setup do
       insert(:plan, name: "Free")
 
-      {source, backend} =
-        setup_clickhouse_test(
-          config: %{
-            read_only_urls: %{
-              "api" => "http://localhost:8123",
-              "dashboard_logs" => "http://localhost:8123"
-            },
-            default_read_cluster: "dashboard_logs"
-          }
-        )
-
-      start_supervised!({ClickHouseAdaptor, backend})
-
-      [source: source, backend: backend]
+      [backend: setup_read_cluster_backend()]
     end
 
     test "routes to the labeled pool for a configured read cluster", %{backend: backend} do
@@ -1286,8 +1269,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
 
       {source, backend} = setup_clickhouse_test()
 
-      start_supervised!({ClickHouseAdaptor, backend})
-
       [source: source, backend: backend]
     end
 
@@ -1313,18 +1294,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     end
 
     test "falls back to the default cluster when the requested cluster is unhealthy" do
-      {_source, backend} =
-        setup_clickhouse_test(
-          config: %{
-            read_only_urls: %{
-              "api" => "http://localhost:8123",
-              "dashboard_logs" => "http://localhost:8123"
-            },
-            default_read_cluster: "dashboard_logs"
-          }
-        )
-
-      start_supervised!({ClickHouseAdaptor, backend})
+      backend = setup_read_cluster_backend()
       stub_read_cluster_connection_error(backend, "api")
 
       log =
@@ -1344,18 +1314,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     end
 
     test "does not emit query error telemetry when the failover retry succeeds" do
-      {_source, backend} =
-        setup_clickhouse_test(
-          config: %{
-            read_only_urls: %{
-              "api" => "http://localhost:8123",
-              "dashboard_logs" => "http://localhost:8123"
-            },
-            default_read_cluster: "dashboard_logs"
-          }
-        )
-
-      start_supervised!({ClickHouseAdaptor, backend})
+      backend = setup_read_cluster_backend()
       stub_read_cluster_connection_error(backend, "api")
       TestUtils.attach_forwarder([:logflare, :clickhouse, :read_pool, :query_error])
       TestUtils.attach_forwarder([:logflare, :clickhouse, :read_pool, :failover])
@@ -1377,18 +1336,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     end
 
     test "emits a single query error when the failover retry also fails" do
-      {_source, backend} =
-        setup_clickhouse_test(
-          config: %{
-            read_only_urls: %{
-              "api" => "http://localhost:8123",
-              "dashboard_logs" => "http://localhost:8123"
-            },
-            default_read_cluster: "dashboard_logs"
-          }
-        )
-
-      start_supervised!({ClickHouseAdaptor, backend})
+      backend = setup_read_cluster_backend()
       stub_read_cluster_connection_error(backend, ["api", "dashboard_logs"])
       TestUtils.attach_forwarder([:logflare, :clickhouse, :read_pool, :query_error])
 
@@ -1410,18 +1358,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     end
 
     test "preserves the endpoint limit when falling back to the default cluster" do
-      {_source, backend} =
-        setup_clickhouse_test(
-          config: %{
-            read_only_urls: %{
-              "api" => "http://localhost:8123",
-              "dashboard_logs" => "http://localhost:8123"
-            },
-            default_read_cluster: "dashboard_logs"
-          }
-        )
-
-      start_supervised!({ClickHouseAdaptor, backend})
+      backend = setup_read_cluster_backend()
       stub_read_cluster_connection_error(backend, "api", self())
 
       assert {:ok, %QueryResult{rows: rows}} =
@@ -1454,7 +1391,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
           }
         )
 
-      start_supervised!({ClickHouseAdaptor, backend})
       stub_read_cluster_queue_timeout(backend, "api_free")
 
       assert {:error, %QueryError{kind: :pool_exhausted}} =
@@ -1474,7 +1410,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
           }
         )
 
-      start_supervised!({ClickHouseAdaptor, backend})
       stub_read_cluster_connection_error(backend, "dashboard_logs")
 
       assert {:error, %QueryError{}} =
@@ -1484,18 +1419,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     end
 
     test "falls back to the default cluster when the requested cluster pool cannot start" do
-      {_source, backend} =
-        setup_clickhouse_test(
-          config: %{
-            read_only_urls: %{
-              "api" => "http://localhost:8123",
-              "dashboard_logs" => "http://localhost:8123"
-            },
-            default_read_cluster: "dashboard_logs"
-          }
-        )
-
-      start_supervised!({ClickHouseAdaptor, backend})
+      backend = setup_read_cluster_backend()
       stub_read_cluster_pool_start_error(backend, "api")
       TestUtils.attach_forwarder([:logflare, :clickhouse, :read_pool, :query_error])
       TestUtils.attach_forwarder([:logflare, :clickhouse, :read_pool, :failover])
@@ -1526,7 +1450,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
           }
         )
 
-      start_supervised!({ClickHouseAdaptor, backend})
       stub_read_cluster_pool_start_error(backend, "dashboard_logs")
       TestUtils.attach_forwarder([:logflare, :clickhouse, :read_pool, :query_error])
 
@@ -1555,7 +1478,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
           }
         )
 
-      start_supervised!({ClickHouseAdaptor, backend})
       stub_read_cluster_connection_error(backend, "adhoc")
 
       log =
@@ -1582,7 +1504,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     end
 
     test "fails when the ingest cluster returns a connection error and logs the ingest URL" do
-      {_source, backend} = setup_clickhouse_test(cleanup?: false)
+      {_source, backend} = setup_clickhouse_test()
 
       stub(Ch, :query, fn _pool, _statement, _params, _opts ->
         {:error, %DBConnection.ConnectionError{message: "unreachable"}}
@@ -1601,8 +1523,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     test "fails when the read cluster returns a connection error" do
       {_source, backend} =
         setup_clickhouse_test(
-          config: %{read_only_urls: %{"reporting" => "http://localhost:8123"}},
-          cleanup?: false
+          config: %{read_only_urls: %{"reporting" => "http://localhost:8123"}}
         )
 
       read_grant_statement = QueryTemplates.read_grant_check_statement()
@@ -1630,7 +1551,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
           }
         )
 
-      start_supervised!({ClickHouseAdaptor, backend})
       assert :ok = ClickHouseAdaptor.test_connection(backend)
     end
 
@@ -1642,8 +1562,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
               "reporting" => "http://localhost:8123",
               "adhoc" => "http://localhost:8124"
             }
-          },
-          cleanup?: false
+          }
         )
 
       stub(Ch, :start_link, fn opts ->
@@ -1674,7 +1593,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
           }
         )
 
-      start_supervised!({ClickHouseAdaptor, backend})
       assert :ok = ClickHouseAdaptor.test_connection(backend)
     end
 
@@ -1687,7 +1605,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
           }
         )
 
-      start_supervised!({ClickHouseAdaptor, backend})
       assert {:error, _} = ClickHouseAdaptor.test_connection(backend)
     end
 
@@ -1700,7 +1617,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
           }
         )
 
-      start_supervised!({ClickHouseAdaptor, backend})
       assert :ok = ClickHouseAdaptor.test_connection(backend)
     end
   end
@@ -1743,8 +1659,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
             read_only_urls: %{"reporting" => "http://localhost:8123"},
             query_user: "ch_reader",
             query_password: "reader_pa55"
-          },
-          cleanup?: false
+          }
         )
 
       test_pid = self()
@@ -1762,10 +1677,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
 
     test "validates the query credentials against the primary url when no read cluster is set" do
       {_source, backend} =
-        setup_clickhouse_test(
-          config: %{query_user: "logflare", query_password: "logflare"},
-          cleanup?: false
-        )
+        setup_clickhouse_test(config: %{query_user: "logflare", query_password: "logflare"})
 
       read_grant_statement = QueryTemplates.read_grant_check_statement()
       test_pid = self()
@@ -1781,7 +1693,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     end
 
     test "skips the read grant check when neither a query user nor a read cluster is set" do
-      {_source, backend} = setup_clickhouse_test(cleanup?: false)
+      {_source, backend} = setup_clickhouse_test()
 
       read_grant_statement = QueryTemplates.read_grant_check_statement()
       test_pid = self()
@@ -1798,10 +1710,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
 
     test "fails when the dedicated query user cannot authenticate" do
       {_source, backend} =
-        setup_clickhouse_test(
-          config: %{query_user: "ch_reader", query_password: "reader_pa55"},
-          cleanup?: false
-        )
+        setup_clickhouse_test(config: %{query_user: "ch_reader", query_password: "reader_pa55"})
 
       log =
         ExUnit.CaptureLog.capture_log(fn ->
@@ -1819,8 +1728,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
           config: %{
             read_only_urls: %{"reporting" => "http://localhost:8123"},
             query_user: "ch_reader"
-          },
-          cleanup?: false
+          }
         )
 
       test_pid = self()
@@ -1844,10 +1752,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
 
     test "succeeds when only the read grant check fails" do
       {_source, backend} =
-        setup_clickhouse_test(
-          config: %{query_user: "ch_reader", query_password: "reader_pa55"},
-          cleanup?: false
-        )
+        setup_clickhouse_test(config: %{query_user: "ch_reader", query_password: "reader_pa55"})
 
       log =
         ExUnit.CaptureLog.capture_log(fn ->
@@ -1859,7 +1764,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     end
 
     test "fails when the ingest grant check fails" do
-      {_source, backend} = setup_clickhouse_test(cleanup?: false)
+      {_source, backend} = setup_clickhouse_test()
 
       grant_check_statement = QueryTemplates.grant_check_statement()
 
@@ -2078,8 +1983,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       {source, backend} =
         setup_clickhouse_test()
 
-      start_supervised!({ClickHouseAdaptor, backend})
-      assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
+      provision_clickhouse_tables!(backend)
 
       [source: source, backend: backend]
     end
@@ -2293,8 +2197,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
 
       {source, backend} = setup_clickhouse_test()
 
-      start_supervised!({ClickHouseAdaptor, backend})
-      assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
+      provision_clickhouse_tables!(backend)
 
       [source: source, backend: backend]
     end
@@ -2355,8 +2258,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       {source, backend} =
         setup_clickhouse_test()
 
-      start_supervised!({ClickHouseAdaptor, backend})
-      assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
+      provision_clickhouse_tables!(backend)
 
       [source: source, backend: backend]
     end
@@ -2405,36 +2307,16 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     end
   end
 
-  describe "execute_query/2" do
+  describe "execute_query/2 replica routing" do
     setup do
       insert(:plan, name: "Free")
 
-      {source, backend} = setup_clickhouse_test()
-
-      start_supervised!({ClickHouseAdaptor, backend})
-
-      [source: source, backend: backend]
-    end
-
-    test "executes simple queries using backend-only interface", %{backend: backend} do
-      result = ClickHouseAdaptor.execute_query(backend, "SELECT 1 as test_value", [])
-
-      assert {:ok, %QueryResult{rows: [%{"test_value" => 1}]}} = result
-    end
-
-    test "converts `@param` syntax to ClickHouse `{param:String}` format", %{backend: backend} do
-      result =
-        ClickHouseAdaptor.execute_query(
-          backend,
-          {"SELECT @test_value as param_result", ["test_value"], %{"test_value" => "hello"}},
-          []
-        )
+      {_source, backend} = setup_clickhouse_test(config: %{replica_routing_param: "project"})
 
-      assert {:ok, %QueryResult{rows: [%{"param_result" => "hello"}]}} = result
+      [backend: backend]
     end
 
-    test "sends the configured routing param as the replica tag header" do
-      backend = start_replica_routing_backend("project")
+    test "sends the configured routing param as the replica tag header", %{backend: backend} do
       parent = self()
 
       expect(Ch, :query, fn pool, statement, params, opts ->
@@ -2452,8 +2334,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       assert_received {:ch_headers, [{"x-clickhouse-replica-tag", "abcdefghij"}]}
     end
 
-    test "sends the replica tag header on the max_limit endpoint path" do
-      backend = start_replica_routing_backend("project")
+    test "sends the replica tag header on the max_limit endpoint path", %{backend: backend} do
       parent = self()
 
       expect(Ch, :query, fn pool, statement, params, opts ->
@@ -2471,8 +2352,8 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       assert_received {:ch_headers, [{"x-clickhouse-replica-tag", "abcdefghij"}]}
     end
 
-    test "does not send a replica tag header when the routing param is absent from the request" do
-      backend = start_replica_routing_backend("project")
+    test "does not send a replica tag header when the routing param is absent from the request",
+         %{backend: backend} do
       parent = self()
 
       expect(Ch, :query, fn pool, statement, params, opts ->
@@ -2490,7 +2371,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       assert_received {:ch_headers, []}
     end
 
-    test "does not send a replica tag header when the backend has no routing param configured",
+    test "does not send a replica tag header for raw string queries without request params",
          %{backend: backend} do
       parent = self()
 
@@ -2500,17 +2381,12 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       end)
 
       assert {:ok, %QueryResult{}} =
-               ClickHouseAdaptor.execute_query(
-                 backend,
-                 {"SELECT 1 as test", [], %{"project" => "abcdefghij"}},
-                 []
-               )
+               ClickHouseAdaptor.execute_query(backend, "SELECT 1 as test", [])
 
       assert_received {:ch_headers, []}
     end
 
-    test "does not send a replica tag header for raw string queries without request params" do
-      backend = start_replica_routing_backend("project")
+    test "ignores a routing param value that is not a printable token", %{backend: backend} do
       parent = self()
 
       expect(Ch, :query, fn pool, statement, params, opts ->
@@ -2519,13 +2395,16 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       end)
 
       assert {:ok, %QueryResult{}} =
-               ClickHouseAdaptor.execute_query(backend, "SELECT 1 as test", [])
+               ClickHouseAdaptor.execute_query(
+                 backend,
+                 {"SELECT 1 as test", [], %{"project" => "abc\r\nX-Injected: 1"}},
+                 []
+               )
 
       assert_received {:ch_headers, []}
     end
 
-    test "ignores a routing param value that is not a printable token" do
-      backend = start_replica_routing_backend("project")
+    test "ignores a routing param value that is not a string", %{backend: backend} do
       parent = self()
 
       expect(Ch, :query, fn pool, statement, params, opts ->
@@ -2536,15 +2415,14 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       assert {:ok, %QueryResult{}} =
                ClickHouseAdaptor.execute_query(
                  backend,
-                 {"SELECT 1 as test", [], %{"project" => "abc\r\nX-Injected: 1"}},
+                 {"SELECT 1 as test", [], %{"project" => ["a", "b"]}},
                  []
                )
 
       assert_received {:ch_headers, []}
     end
 
-    test "ignores a routing param value that is not a string" do
-      backend = start_replica_routing_backend("project")
+    test "ignores a routing param value containing non-ASCII characters", %{backend: backend} do
       parent = self()
 
       expect(Ch, :query, fn pool, statement, params, opts ->
@@ -2555,16 +2433,16 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       assert {:ok, %QueryResult{}} =
                ClickHouseAdaptor.execute_query(
                  backend,
-                 {"SELECT 1 as test", [], %{"project" => ["a", "b"]}},
+                 {"SELECT 1 as test", [], %{"project" => "café"}},
                  []
                )
 
       assert_received {:ch_headers, []}
     end
 
-    test "ignores a routing param value containing non-ASCII characters" do
-      backend = start_replica_routing_backend("project")
+    test "sends a routing param value of exactly 256 bytes", %{backend: backend} do
       parent = self()
+      value = String.duplicate("a", 256)
 
       expect(Ch, :query, fn pool, statement, params, opts ->
         send(parent, {:ch_headers, Keyword.get(opts, :headers, [])})
@@ -2574,17 +2452,15 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       assert {:ok, %QueryResult{}} =
                ClickHouseAdaptor.execute_query(
                  backend,
-                 {"SELECT 1 as test", [], %{"project" => "café"}},
+                 {"SELECT 1 as test", [], %{"project" => value}},
                  []
                )
 
-      assert_received {:ch_headers, []}
+      assert_received {:ch_headers, [{"x-clickhouse-replica-tag", ^value}]}
     end
 
-    test "sends a routing param value of exactly 256 bytes" do
-      backend = start_replica_routing_backend("project")
+    test "ignores a routing param value of 257 bytes", %{backend: backend} do
       parent = self()
-      value = String.duplicate("a", 256)
 
       expect(Ch, :query, fn pool, statement, params, opts ->
         send(parent, {:ch_headers, Keyword.get(opts, :headers, [])})
@@ -2594,15 +2470,42 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       assert {:ok, %QueryResult{}} =
                ClickHouseAdaptor.execute_query(
                  backend,
-                 {"SELECT 1 as test", [], %{"project" => value}},
+                 {"SELECT 1 as test", [], %{"project" => String.duplicate("a", 257)}},
                  []
                )
 
-      assert_received {:ch_headers, [{"x-clickhouse-replica-tag", ^value}]}
+      assert_received {:ch_headers, []}
+    end
+  end
+
+  describe "execute_query/2" do
+    setup do
+      insert(:plan, name: "Free")
+
+      {source, backend} = setup_clickhouse_test()
+
+      [source: source, backend: backend]
+    end
+
+    test "executes simple queries using backend-only interface", %{backend: backend} do
+      result = ClickHouseAdaptor.execute_query(backend, "SELECT 1 as test_value", [])
+
+      assert {:ok, %QueryResult{rows: [%{"test_value" => 1}]}} = result
     end
 
-    test "ignores a routing param value of 257 bytes" do
-      backend = start_replica_routing_backend("project")
+    test "converts `@param` syntax to ClickHouse `{param:String}` format", %{backend: backend} do
+      result =
+        ClickHouseAdaptor.execute_query(
+          backend,
+          {"SELECT @test_value as param_result", ["test_value"], %{"test_value" => "hello"}},
+          []
+        )
+
+      assert {:ok, %QueryResult{rows: [%{"param_result" => "hello"}]}} = result
+    end
+
+    test "does not send a replica tag header when the backend has no routing param configured",
+         %{backend: backend} do
       parent = self()
 
       expect(Ch, :query, fn pool, statement, params, opts ->
@@ -2613,7 +2516,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       assert {:ok, %QueryResult{}} =
                ClickHouseAdaptor.execute_query(
                  backend,
-                 {"SELECT 1 as test", [], %{"project" => String.duplicate("a", 257)}},
+                 {"SELECT 1 as test", [], %{"project" => "abcdefghij"}},
                  []
                )
 
@@ -2621,19 +2524,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     end
 
     test "keeps the replica tag header on the default cluster failover retry" do
-      {_source, backend} =
-        setup_clickhouse_test(
-          config: %{
-            replica_routing_param: "project",
-            read_only_urls: %{
-              "api" => "http://localhost:8123",
-              "dashboard_logs" => "http://localhost:8123"
-            },
-            default_read_cluster: "dashboard_logs"
-          }
-        )
-
-      start_supervised!({ClickHouseAdaptor, backend}, id: {:replica_routing, backend.id})
+      backend = setup_read_cluster_backend(%{replica_routing_param: "project"})
       parent = self()
       backend_id = backend.id
 
@@ -3101,7 +2992,7 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       source: source,
       backend: backend
     } do
-      assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
+      provision_clickhouse_tables!(backend)
 
       log_events =
         for i <- 1..5 do
@@ -3167,8 +3058,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
           default_ingest?: true
         )
 
-      start_supervised!({ClickHouseAdaptor, backend})
-
       [backend: backend, user: user, source1: source1_with_backend, source2: source2]
     end
 
@@ -3280,7 +3169,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       insert(:plan, name: "Free")
       {source, backend} = setup_clickhouse_test()
 
-      start_supervised!({ClickHouseAdaptor, backend})
       [source: source, backend: backend]
     end
 
@@ -3329,7 +3217,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       backend: backend1
     } do
       {_source2, backend2} = setup_clickhouse_test(source: source)
-      start_supervised!({ClickHouseAdaptor, backend2}, id: :adaptor2)
 
       {:ok, _} = ClickHouseAdaptor.execute_ch_query(backend2, "SELECT 1")
       assert ConnectionManager.pool_active?(backend2)
@@ -3347,7 +3234,6 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
       insert(:plan, name: "Free")
       {source, backend} = setup_clickhouse_test()
 
-      start_supervised!({ClickHouseAdaptor, backend})
       [source: source, backend: backend]
     end
 
@@ -3556,9 +3442,21 @@ defmodule Logflare.Backends.Adaptor.ClickHouseAdaptorTest do
     {query, declared_params, input_params, %EndpointQuery{max_limit: max_limit}}
   end
 
-  defp start_replica_routing_backend(param) do
-    {_source, backend} = setup_clickhouse_test(config: %{replica_routing_param: param})
-    start_supervised!({ClickHouseAdaptor, backend}, id: {:replica_routing, backend.id})
+  @spec setup_read_cluster_backend(map()) :: Backend.t()
+  defp setup_read_cluster_backend(config \\ %{}) do
+    config =
+      Map.merge(
+        %{
+          read_only_urls: %{
+            "api" => "http://localhost:8123",
+            "dashboard_logs" => "http://localhost:8123"
+          },
+          default_read_cluster: "dashboard_logs"
+        },
+        config
+      )
+
+    {_source, backend} = setup_clickhouse_test(config: config)
     backend
   end
 
diff --git a/test/logflare/backends/consolidated_sup_test.exs b/test/logflare/backends/consolidated_sup_test.exs
index ef011c1e6a..94fd056192 100644
--- a/test/logflare/backends/consolidated_sup_test.exs
+++ b/test/logflare/backends/consolidated_sup_test.exs
@@ -10,6 +10,7 @@ defmodule Logflare.Backends.ConsolidatedSupTest do
       insert(:plan, name: "Free")
 
       {_source, backend} = setup_clickhouse_test()
+      on_exit(fn -> ConsolidatedSup.stop_pipeline(backend.id) end)
 
       [backend: backend]
     end
@@ -82,14 +83,6 @@ defmodule Logflare.Backends.ConsolidatedSupTest do
 
       IngestEventQueue.upsert_tid({:consolidated, backend.id, nil})
 
-      on_exit(fn ->
-        try do
-          ConsolidatedSup.stop_pipeline(backend.id)
-        catch
-          _kind, _value -> :ok
-        end
-      end)
-
       [source: source, backend: backend]
     end
 
@@ -97,7 +90,7 @@ defmodule Logflare.Backends.ConsolidatedSupTest do
       source: source,
       backend: backend
     } do
-      assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
+      provision_clickhouse_tables!(backend)
       assert {:ok, _pid} = ConsolidatedSup.start_pipeline(backend)
 
       events = for _ <- 1..5, do: build(:log_event, source: source)
diff --git a/test/logflare/endpoints_test.exs b/test/logflare/endpoints_test.exs
index f223e7e84a..f14ad37449 100644
--- a/test/logflare/endpoints_test.exs
+++ b/test/logflare/endpoints_test.exs
@@ -832,8 +832,7 @@ defmodule Logflare.EndpointsTest do
       source = insert(:source, user: user, name: "c")
       {_source, backend} = setup_clickhouse_test(user: user, source: source)
 
-      start_supervised!({ClickHouseAdaptor, backend})
-      assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
+      provision_clickhouse_tables!(backend)
 
       log_events =
         for i <- 1..5 do
diff --git a/test/logflare/single_tenant_test.exs b/test/logflare/single_tenant_test.exs
index 4c511503e0..a8118f050b 100644
--- a/test/logflare/single_tenant_test.exs
+++ b/test/logflare/single_tenant_test.exs
@@ -324,14 +324,7 @@ defmodule Logflare.SingleTenantTest do
   end
 
   describe "single tenant mode using ClickHouse" do
-    TestUtils.setup_single_tenant(
-      backend_type: :clickhouse,
-      clickhouse_backend_adapter_opts: [
-        url: "http://localhost:8123",
-        database: "logflare_test",
-        port: 8123
-      ]
-    )
+    TestUtils.setup_single_tenant(backend_type: :clickhouse)
 
     test "returns nil before the default user exists" do
       assert SingleTenant.get_default_user() == nil
@@ -366,6 +359,7 @@ defmodule Logflare.SingleTenantTest do
       Application.put_env(:logflare, :supabase_mode, true)
 
       on_exit(fn -> Application.put_env(:logflare, :supabase_mode, previous_supabase_mode) end)
+      on_exit(fn -> ConsolidatedSup.stop_pipeline(0) end)
 
       Logflare.Application.startup_tasks()
 
@@ -390,8 +384,6 @@ defmodule Logflare.SingleTenantTest do
       assert SingleTenant.get_default_backend() == backend
       assert Backends.get_backend(0) == backend
       assert Backends.list_backends(user_id: user_id) == []
-
-      on_exit(fn -> ConsolidatedSup.stop_pipeline(backend.id) end)
     end
   end
 
diff --git a/test/logflare/sql_test.exs b/test/logflare/sql_test.exs
index 9733ddfc28..8fb0eca78b 100644
--- a/test/logflare/sql_test.exs
+++ b/test/logflare/sql_test.exs
@@ -662,8 +662,7 @@ defmodule Logflare.SqlTest do
       # setup local clickhouse for e2e test
       {source, backend} = setup_clickhouse_test(source: source, user: user)
 
-      {:ok, _pid} = ClickHouseAdaptor.start_link(backend)
-      assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
+      provision_clickhouse_tables!(backend)
 
       log_events = [
         build_mapped_log_event(
diff --git a/test/logflare_web/controllers/api/query_controller_test.exs b/test/logflare_web/controllers/api/query_controller_test.exs
index c3d8339e8a..a34bf795a9 100644
--- a/test/logflare_web/controllers/api/query_controller_test.exs
+++ b/test/logflare_web/controllers/api/query_controller_test.exs
@@ -1,7 +1,6 @@
 defmodule LogflareWeb.Api.QueryControllerTest do
   use LogflareWeb.ConnCase
 
-  alias Logflare.Backends.Adaptor.ClickHouseAdaptor
   alias Logflare.Backends.Adaptor.PostgresAdaptor
   alias Logflare.DataCase
 
@@ -215,7 +214,6 @@ defmodule LogflareWeb.Api.QueryControllerTest do
   describe "backend_id parameter" do
     test "?sql= with backend_id uses backend's language", %{conn: conn, user: user} do
       {_source, backend} = DataCase.setup_clickhouse_test(user: user)
-      start_supervised!({ClickHouseAdaptor, backend})
 
       query = "SELECT dummy AS my_time FROM system.one LIMIT 1 BY dummy"
 
@@ -236,7 +234,6 @@ defmodule LogflareWeb.Api.QueryControllerTest do
 
     test "?ch_sql= with backend_id", %{conn: conn, user: user} do
       {_source, backend} = DataCase.setup_clickhouse_test(user: user)
-      start_supervised!({ClickHouseAdaptor, backend})
 
       query = "SELECT dummy AS my_time FROM system.one LIMIT 1 BY dummy"
 
@@ -253,8 +250,7 @@ defmodule LogflareWeb.Api.QueryControllerTest do
       conn: conn,
       user: user
     } do
-      {_source, backend} = DataCase.setup_clickhouse_test(user: user)
-      start_supervised!({ClickHouseAdaptor, backend})
+      {_source, _backend} = DataCase.setup_clickhouse_test(user: user)
 
       query = "SELECT dummy AS my_time FROM system.one LIMIT 1 BY dummy"
 
@@ -269,7 +265,6 @@ defmodule LogflareWeb.Api.QueryControllerTest do
 
     test "bq_sql param with backend_id executes query", %{conn: conn, user: user} do
       {_source, clickhouse_backend} = DataCase.setup_clickhouse_test(user: user)
-      start_supervised!({ClickHouseAdaptor, clickhouse_backend})
 
       query = ~S|select 1 as my_time|
 
@@ -284,7 +279,6 @@ defmodule LogflareWeb.Api.QueryControllerTest do
 
     test "?sql= takes precedence over deprecated params", %{conn: conn, user: user} do
       {_source, backend} = DataCase.setup_clickhouse_test(user: user)
-      start_supervised!({ClickHouseAdaptor, backend})
 
       response =
         conn
diff --git a/test/logflare_web/live_views/endpoints_live_test.exs b/test/logflare_web/live_views/endpoints_live_test.exs
index 74d8ac9d92..963db84545 100644
--- a/test/logflare_web/live_views/endpoints_live_test.exs
+++ b/test/logflare_web/live_views/endpoints_live_test.exs
@@ -4,7 +4,7 @@ defmodule LogflareWeb.EndpointsLiveTest do
   use LogflareWeb.ConnCase
 
   import Logflare.ClickHouseMappedEvents, only: [build_mapped_log_event: 1]
-  import Logflare.DataCase, only: [setup_clickhouse_test: 1]
+  import Logflare.DataCase, only: [provision_clickhouse_tables!: 1, setup_clickhouse_test: 1]
 
   setup %{conn: conn} do
     insert(:plan)
@@ -1160,8 +1160,7 @@ defmodule LogflareWeb.EndpointsLiveTest do
 
       {edge_source, backend} = setup_clickhouse_test(source: edge_source, user: user)
 
-      start_supervised!({ClickHouseAdaptor, backend})
-      assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
+      provision_clickhouse_tables!(backend)
 
       log_events = [
         build_mapped_log_event(
diff --git a/test/logflare_web/live_views/query_live_test.exs b/test/logflare_web/live_views/query_live_test.exs
index 90826d89f6..8dbb9df72f 100644
--- a/test/logflare_web/live_views/query_live_test.exs
+++ b/test/logflare_web/live_views/query_live_test.exs
@@ -191,8 +191,6 @@ defmodule LogflareWeb.QueryLiveTest do
 
       {source, backend} = Logflare.DataCase.setup_clickhouse_test(user: user, source: source)
 
-      start_supervised!({ClickHouseAdaptor, backend})
-
       query = ~s(select non_existent from "#{source.name}")
 
       {:ok, view, _html} =
diff --git a/test/support/data_case.ex b/test/support/data_case.ex
index 88b1a87e64..19e8008a71 100644
--- a/test/support/data_case.ex
+++ b/test/support/data_case.ex
@@ -16,7 +16,10 @@ defmodule Logflare.DataCase do
 
   alias Ecto.Adapters.SQL
   alias Logflare.Backends.Adaptor.ClickHouseAdaptor
+  alias Logflare.Backends.Adaptor.ClickHouseAdaptor.EndpointUtils
+  alias Logflare.Backends.Backend
   alias Logflare.Backends.ConsolidatedSup
+  alias Logflare.TestUtils
 
   using do
     quote do
@@ -117,59 +120,38 @@ defmodule Logflare.DataCase do
   defdelegate errors_on(changeset), to: LogflareWeb.Utils, as: :changeset_errors
 
   @doc """
-  Sets up a ClickHouse test environment with automatic cleanup.
+  Creates ClickHouse source and backend fixtures.
 
-  Returns `{source, backend}` tuple. Registers cleanup via `on_exit/1`.
+  Use `provision_clickhouse_tables!/1` to create tables with automatic teardown,
+  or `drop_clickhouse_tables_on_exit/1` when testing provisioning or ingestion startup.
 
   ## Options
   - `:config` - Custom ClickHouse configuration (merged with defaults)
   - `:user` - Existing user to use (creates one if not provided)
   - `:source` - Existing source to use (creates one if not provided)
-  - `:default_ingest_backend?` - Whether to set the backend as the default ingest backend (requires a source to be provided with the default ingest backend option set to true)
-  - `:cleanup?` - Whether to drop the backend's ClickHouse tables on exit (defaults to true)
+  - `:default_ingest?` - Whether to set the backend as the default ingest backend
   """
+  @spec setup_clickhouse_test(keyword()) ::
+          {Logflare.Sources.Source.t(), Logflare.Backends.Backend.t()}
   def setup_clickhouse_test(opts \\ []) do
     config = Keyword.get(opts, :config, %{})
-    default_ingest_backend? = Keyword.get(opts, :default_ingest_backend?, false)
 
     if not (is_map_key(config, :url) or is_map_key(config, :port)) do
       ensure_clickhouse_reachable!()
     end
 
-    user =
-      case Keyword.get(opts, :user) do
-        nil ->
-          Logflare.Factory.insert(:user)
-
-        existing_user ->
-          existing_user
-      end
-
+    user = Keyword.get(opts, :user) || Logflare.Factory.insert(:user)
     source = Keyword.get(opts, :source) || Logflare.Factory.insert(:source, user: user)
 
-    default_config = %{
-      url: "http://localhost:8123",
-      database: "logflare_test",
-      username: "logflare",
-      password: "logflare",
-      port: 8123,
-      ingest_pool_size: 5,
-      query_pool_size: 3
-    }
-
     backend =
       Logflare.Factory.insert(:backend,
         type: :clickhouse,
-        config: Map.merge(default_config, config),
-        default_ingest?: default_ingest_backend?,
+        config: Map.merge(TestUtils.clickhouse_config(), config),
+        default_ingest?: Keyword.get(opts, :default_ingest?, false),
         user: user,
         sources: [source]
       )
 
-    if Keyword.get(opts, :cleanup?, true) do
-      on_exit(fn -> cleanup_clickhouse_tables(backend) end)
-    end
-
     {source, backend}
   end
 
@@ -185,64 +167,56 @@ defmodule Logflare.DataCase do
     end
   end
 
-  @doc """
-  Builds ClickHouse connection options for testing.
-  """
-  def build_clickhouse_connection_opts(source, backend, type) when type in [:ingest, :query] do
-    base_opts = [
-      scheme: "http",
-      hostname: "localhost",
-      port: 8123,
-      database: "logflare_test",
-      username: "logflare",
-      password: "logflare"
-    ]
-
-    type_specific_opts =
-      case type do
-        :ingest -> [pool_size: 5, timeout: 15_000]
-        :query -> [pool_size: 3, timeout: 60_000]
-      end
-
-    connection_name =
-      case type do
-        :ingest -> ClickHouseAdaptor.connection_pool_via({source, backend})
-        :query -> ClickHouseAdaptor.connection_pool_via(backend)
-      end
-
-    base_opts
-    |> Keyword.merge(type_specific_opts)
-    |> Keyword.put(:name, connection_name)
+  @spec provision_clickhouse_tables!(Backend.t()) :: :ok
+  def provision_clickhouse_tables!(backend) do
+    drop_clickhouse_tables_on_exit(backend)
+    assert :ok = ClickHouseAdaptor.provision_ingest_tables(backend)
   end
 
   @doc """
-  Cleanup ClickHouse tables for a given `Backend`.
-
-  Drops all type-specific tables (`_logs`, `_metrics`, `_traces`).
+  Registers teardown to synchronously drop a backend's typed tables after a test,
+  stopping its pipeline first. Uses the primary connection, not read routing.
   """
-  def cleanup_clickhouse_tables(backend) do
+  @spec drop_clickhouse_tables_on_exit(Backend.t()) :: :ok
+  def drop_clickhouse_tables_on_exit(%Backend{config: config} = backend) do
     tables =
-      Enum.map([:log, :metric, :trace], fn type ->
-        ClickHouseAdaptor.clickhouse_ingest_table_name(backend, type)
-      end)
-
-    drop_query =
-      tables
-      |> Enum.map_join("; ", fn table_name -> "DROP TABLE IF EXISTS #{table_name}" end)
-
-    try do
-      ClickHouseAdaptor.execute_ch_query(
-        backend,
-        drop_query,
-        [],
-        pool_timeout: 1_000
+      Enum.map(
+        [:log, :metric, :trace],
+        &ClickHouseAdaptor.clickhouse_ingest_table_name(backend, &1)
       )
 
+    {scheme, hostname, port} = EndpointUtils.origin(config.url, config[:port])
+
+    opts = [
+      scheme: scheme,
+      hostname: hostname,
+      port: port,
+      database: config.database,
+      username: config[:username],
+      password: config[:password],
+      pool_size: 1,
+      timeout: 60_000
+    ]
+
+    on_exit(fn ->
       ConsolidatedSup.stop_pipeline(backend.id)
-    rescue
-      _ -> :ok
-    catch
-      :exit, _ -> :ok
+      drop_clickhouse_tables(opts, tables)
+    end)
+  end
+
+  @spec drop_clickhouse_tables(keyword(), [String.t()]) :: :ok
+  defp drop_clickhouse_tables(opts, tables) do
+    {:ok, conn} = Ch.start_link(opts)
+
+    try do
+      Enum.each(tables, fn table ->
+        Ch.query!(conn, "DROP TABLE IF EXISTS #{table} SYNC", [],
+          timeout: 60_000,
+          pool_timeout: 60_000
+        )
+      end)
+    after
+      GenServer.stop(conn)
     end
   end
 
diff --git a/test/support/test_utils.ex b/test/support/test_utils.ex
index d6cb5a992b..0ccf899f3d 100644
--- a/test/support/test_utils.ex
+++ b/test/support/test_utils.ex
@@ -27,7 +27,6 @@ defmodule Logflare.TestUtils do
   - :seed_user - boolean - enable to seed default plan and user
   - :supabase_mode - enable to seed supabase data
   - :backend_type - the selected single-tenant backend
-  - :clickhouse_backend_adapter_opts - ClickHouse connection options
   """
   defmacro setup_single_tenant(opts \\ []) do
     opts =
@@ -36,12 +35,7 @@ defmodule Logflare.TestUtils do
         supabase_mode: false,
         bigquery_project_id: random_string(),
         backend_type: :bigquery,
-        pg_schema: nil,
-        clickhouse_backend_adapter_opts: [
-          url: "http://localhost:8123",
-          database: "logflare_test",
-          port: 8123
-        ]
+        pg_schema: nil
       })
 
     quote do
@@ -139,14 +133,16 @@ defmodule Logflare.TestUtils do
     end
   end
 
-  defp setup_single_tenant_backend(%{
-         backend_type: :clickhouse,
-         clickhouse_backend_adapter_opts: opts
-       }) do
+  defp setup_single_tenant_backend(%{backend_type: :clickhouse}) do
     quote do
       setup do
         previous = Application.get_env(:logflare, :clickhouse_backend_adapter)
-        Application.put_env(:logflare, :clickhouse_backend_adapter, unquote(opts))
+
+        Application.put_env(
+          :logflare,
+          :clickhouse_backend_adapter,
+          Map.to_list(Logflare.TestUtils.clickhouse_config())
+        )
 
         on_exit(fn -> Application.put_env(:logflare, :clickhouse_backend_adapter, previous) end)
         :ok
@@ -154,6 +150,17 @@ defmodule Logflare.TestUtils do
     end
   end
 
+  @spec clickhouse_config() :: map()
+  def clickhouse_config do
+    %{
+      url: "http://localhost:8123",
+      database: "logflare_test",
+      username: "logflare",
+      password: "logflare",
+      port: 8123
+    }
+  end
+
   def default_bq_schema, do: SchemaBuilder.initial_table_schema()
 
   def build_bq_schema(params) do

From e012582e968b79740f26695494f487a1e9420952 Mon Sep 17 00:00:00 2001
From: Matt Stubbs <matt@yellowrobot.com.au>
Date: Tue, 13 Oct 2026 10:56:16 +1000
Subject: [PATCH 17/17] fix: reconcile source startup lifecycle after rebase

---
 .reach.baseline.json                          |  6 ++---
 lib/logflare/sources/source/supervisor.ex     |  2 +-
 .../sources/source/supervisor_test.exs        | 22 +++++++++++++++++++
 3 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/.reach.baseline.json b/.reach.baseline.json
index f0fc868731..b2d31227b6 100644
--- a/.reach.baseline.json
+++ b/.reach.baseline.json
@@ -781,10 +781,10 @@
     {
       "source": "smells",
       "kind": "redundant_computation",
-      "fingerprint": "sha256:7f50270eeee917c359a84869adaf9f5e5a01a3e4e7853c4dd9111f8159773b82",
-      "message": "Logflare.Auth.list_valid_access_tokens called twice with same args (line 188 and 218)",
+      "fingerprint": "sha256:9a7130a7a6e263eec866c2d02c31a837cb2fc4f7ed89ceac5eda162e7d76570e",
+      "message": "Logflare.Auth.list_valid_access_tokens called twice with same args (line 187 and 217)",
       "file": "lib/logflare/single_tenant.ex",
-      "line": 218
+      "line": 217
     },
     {
       "source": "smells",
diff --git a/lib/logflare/sources/source/supervisor.ex b/lib/logflare/sources/source/supervisor.ex
index b6b13f8087..a6d17f4b7c 100644
--- a/lib/logflare/sources/source/supervisor.ex
+++ b/lib/logflare/sources/source/supervisor.ex
@@ -148,7 +148,7 @@ defmodule Logflare.Sources.Source.Supervisor do
         {:error, reason}
 
       {:error, :start_timeout} = err ->
-        init_table(source.token)
+        SystemBackend.on_source_start(source)
         err
 
       {:error, _reason} = err ->
diff --git a/test/logflare/sources/source/supervisor_test.exs b/test/logflare/sources/source/supervisor_test.exs
index 33669f8350..f7d99bf590 100644
--- a/test/logflare/sources/source/supervisor_test.exs
+++ b/test/logflare/sources/source/supervisor_test.exs
@@ -1,3 +1,25 @@
 defmodule Logflare.Sources.Source.SupervisorTest do
   use Logflare.DataCase
+
+  alias Logflare.Backends
+  alias Logflare.Backends.Adaptor.BigQueryAdaptor
+  alias Logflare.SingleTenant
+  alias Logflare.Sources.Cache
+  alias Logflare.Sources.Source.Supervisor
+
+  test "runs the system backend source hook when source startup times out" do
+    source = build(:source)
+
+    stub(SingleTenant, :single_tenant?, fn -> false end)
+
+    expect(Cache, :get_by, fn [token: token] ->
+      assert token == source.token
+      source
+    end)
+
+    expect(Backends, :start_source_sup, fn ^source -> {:error, :start_timeout} end)
+    expect(BigQueryAdaptor, :on_source_start, fn ^source -> :ok end)
+
+    assert {:noreply, nil} = Supervisor.handle_cast({:create, source.token}, nil)
+  end
 end