Add sender queue that expires oldest first

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## Unreleased
+
+* [Changed] DogStatsD background sender queue now evicts the oldest queued payloads when full, and drops payloads without an explicit timestamp after they have been queued for more than 10 seconds. See [#986](https://github.com/DataDog/datadogpy/pull/986).
+
 ## v0.53.0 / 2026-07-24
 
 * [Fixed] Add DD_DOGSTATSD_URL support for Unix and UDP URLs. See [#968](https://github.com/DataDog/datadogpy/pull/968).

datadog/dogstatsd/context.py

@@ -6,14 +6,9 @@
 import sys
 
 
-try:
-    from time import monotonic  # type: ignore[attr-defined]
-except ImportError:
-    from time import time as monotonic
-
 # datadog
 from datadog.dogstatsd.context_async import _get_wrapped_co
-from datadog.util.compat import iscoroutinefunction
+from datadog.util.compat import iscoroutinefunction, monotonic
 
 
 if sys.version_info[:2] >= (3, 5):

datadog/dogstatsd/context_async.py

@@ -23,10 +23,8 @@
 # https://github.com/python/mypy/issues/6897
 ASYNC_SOURCE = r'''
 from functools import wraps
-try:
-    from time import monotonic
-except ImportError:
-    from time import time as monotonic
+
+from datadog.util.compat import monotonic
 
 
 def _get_wrapped_co(self, func):

datadog/threadstats/base.py

@@ -16,17 +16,13 @@
 from functools import wraps
 from time import time
 
-try:
-    from time import monotonic  # type: ignore[attr-defined]
-except ImportError:
-    from time import time as monotonic
-
 # datadog
 from datadog.api.exceptions import ApiNotInitialized
 from datadog.threadstats.constants import MetricType
 from datadog.threadstats.events import EventsAggregator
 from datadog.threadstats.metrics import MetricsAggregator, Counter, Gauge, Histogram, Timing, Distribution, Set
 from datadog.threadstats.reporters import HttpReporter
+from datadog.util.compat import monotonic
 
 # Loggers
 log = logging.getLogger("datadog.threadstats")

datadog/util/compat.py

@@ -109,6 +109,16 @@ def emit(self, record):
             pass
 
 
+# Python >= 3.3
+if sys.version_info >= (3, 3):
+    from time import monotonic
+# Python 2.x: there is no monotonic clock, so fall back to the wall clock.
+# Callers that compare two readings (elapsed time, queue entry age) are
+# therefore sensitive to the clock being stepped backwards on Python 2.
+else:
+    from time import time as monotonic
+
+
 def _is_py_version_higher_than(major, minor=0):
     # type: (int, int) -> bool
     """

tests/integration/dogstatsd/test_statsd_sender.py

@@ -103,7 +103,8 @@ def test_fork_hooks(disable_background_sender, disable_buffering):
     assert statsd._flush_thread is None
     assert statsd._sender_thread is None
     assert statsd._queue is None or statsd._queue.empty()
-    assert len(statsd._buffer) == 0
+    # Buffered lines are split by expiry policy, so check every batch.
+    assert not statsd._buffer and not statsd._buffer_rs
 
     statsd.post_fork_parent()