Filter duplicate logs out of some logger's logs that might otherwise endlessly log

CHANGELOG.md

@@ -10,6 +10,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Overwrite logging.config.fileConfig and logging.config.dictConfig to ensure
 the OTLP `LogHandler` remains attached to the root logger. Fix a bug that
 can cause a deadlock to occur over `logging._lock` in some cases ([#4636](https://github.com/open-telemetry/opentelemetry-python/pull/4636)).
+- Filter duplicate logs emitted from the OTLP exporters to avoid endlessly logging when the OTLP logger itself
+is failing to export logs.
 
 ## Version 1.35.0/0.56b0 (2025-07-11)
 

exporter/opentelemetry-exporter-otlp-proto-common/src/opentelemetry/exporter/otlp/proto/common/_internal/__init__.py

@@ -16,6 +16,7 @@
 from __future__ import annotations
 
 import logging
+import time
 from collections.abc import Sequence
 from typing import (
     Any,
@@ -51,6 +52,21 @@
 _ResourceDataT = TypeVar("_ResourceDataT")
 
 
+class DuplicateFilter(logging.Filter):
+    def filter(self, record):
+        current_log = (
+            record.module,
+            record.levelno,
+            record.msg,
+            time.time() // 60,
+        )
+        if current_log != getattr(self, "last_log", None):
+            self.last_log = current_log
+            return True
+        # False means python's `logging` module will no longer process this log.
+        return False
+
+
 def _encode_instrumentation_scope(
     instrumentation_scope: InstrumentationScope,
 ) -> PB2InstrumentationScope:

exporter/opentelemetry-exporter-otlp-proto-common/tests/test_common.py

@@ -0,0 +1,16 @@
+import logging
+import unittest
+
+from opentelemetry.exporter.otlp.proto.common._internal import (
+    DuplicateFilter,
+)
+
+
+class TestCommonFuncs(unittest.TestCase):
+    def test_duplicate_logs_filter_works(self):
+        test_logger = logging.getLogger("testLogger")
+        test_logger.addFilter(DuplicateFilter())
+        with self.assertLogs("testLogger") as cm:
+            test_logger.info("message")
+            test_logger.info("message")
+        self.assertEqual(len(cm.output), 1)

exporter/opentelemetry-exporter-otlp-proto-grpc/src/opentelemetry/exporter/otlp/proto/grpc/exporter.py

@@ -48,6 +48,7 @@
     ssl_channel_credentials,
 )
 from opentelemetry.exporter.otlp.proto.common._internal import (
+    DuplicateFilter,
     _get_resource_data,
 )
 from opentelemetry.exporter.otlp.proto.grpc import (
@@ -87,6 +88,8 @@
 )
 _MAX_RETRYS = 6
 logger = getLogger(__name__)
+# This prevents logs generated when a log fails to be written to generate another log which fails to be written etc. etc.
+logger.addFilter(DuplicateFilter())
 SDKDataT = TypeVar("SDKDataT")
 ResourceDataT = TypeVar("ResourceDataT")
 TypingResourceT = TypeVar("TypingResourceT")

exporter/opentelemetry-exporter-otlp-proto-http/src/opentelemetry/exporter/otlp/proto/http/_log_exporter/__init__.py

@@ -24,6 +24,9 @@
 import requests
 from requests.exceptions import ConnectionError
 
+from opentelemetry.exporter.otlp.proto.common._internal import (
+    DuplicateFilter,
+)
 from opentelemetry.exporter.otlp.proto.common._log_encoder import encode_logs
 from opentelemetry.exporter.otlp.proto.http import (
     _OTLP_HTTP_HEADERS,
@@ -56,6 +59,8 @@
 from opentelemetry.util.re import parse_env_headers
 
 _logger = logging.getLogger(__name__)
+# This prevents logs generated when a log fails to be written to generate another log which fails to be written etc. etc.
+_logger.addFilter(DuplicateFilter())
 
 
 DEFAULT_COMPRESSION = Compression.NoCompression