Allow slowlog collection to fail (#20261)

* Allow slowlog collection to fail

* Add changelog

* Add test

* Run formatter

* Fix test and add second one

* Remove unnecessary aggregator param

Author: dkirov-dd

redisdb/changelog.d/20261.fixed

@@ -0,0 +1 @@
+Allow slowlog collection to fail without error to support some managed Redis that do not allow SLOWLOG GET.

redisdb/datadog_checks/redisdb/redisdb.py

@@ -516,7 +516,11 @@ def upstream_parse_slowlog_get(response, **options):
             max_slow_entries = int(self.instance.get(MAX_SLOW_ENTRIES_KEY))
 
         # Get all slowlog entries
-        slowlogs = conn.slowlog_get(max_slow_entries)
+        try:
+            slowlogs = conn.slowlog_get(max_slow_entries)
+        except redis.ResponseError:
+            self.log.debug("Unable to collect slow log: SLOWLOG GET disabled in some managed Redis.")
+            return
 
         # Find slowlog entries between last timestamp and now using start_time
         slowlogs = [s for s in slowlogs if s['start_time'] > self.last_timestamp_seen]

redisdb/tests/test_unit.py

@@ -3,6 +3,7 @@
 # Licensed under a 3-clause BSD style license (see LICENSE)
 import mock
 import pytest
+from redis.exceptions import ResponseError
 
 from datadog_checks.dev.utils import get_metadata_metrics
 
@@ -102,3 +103,36 @@ def test__check_total_commands_processed_present(check, aggregator, redis_instan
 
     # Assert that the `redis.net.commands` metric was sent
     aggregator.assert_metric('redis.net.commands', value=1000, tags=['test_total_commands_processed'])
+
+
+def test_slowlog_quiet_failure(check, aggregator, redis_instance):
+    """
+    The check should not fail if the slowlog command fails with redis.ResponseError
+    """
+    redis_check = check(redis_instance)
+
+    # Mock the connection object returned by _get_conn
+    mock_conn = mock.MagicMock()
+    mock_conn.slowlog_get.side_effect = ResponseError('ERR unknown command `SLOWLOG`')
+    mock_conn.config_get.return_value = {'slowlog-max-len': '128'}
+
+    with mock.patch.object(redis_check, '_get_conn', return_value=mock_conn):
+        redis_check._check_slowlog()
+        # Assert that no metrics were sent
+        aggregator.assert_metric('redis.slowlog.micros', count=0)
+
+
+def test_slowlog_loud_failure(check, redis_instance):
+    """
+    The check should fail if the slowlog command fails for any other reason
+    """
+    redis_check = check(redis_instance)
+
+    # Mock the connection object returned by _get_conn
+    mock_conn = mock.MagicMock()
+    mock_conn.slowlog_get.side_effect = RuntimeError('Some other error')
+    mock_conn.config_get.return_value = {'slowlog-max-len': '128'}
+
+    with mock.patch.object(redis_check, '_get_conn', return_value=mock_conn):
+        with pytest.raises(RuntimeError, match='Some other error'):
+            redis_check._check_slowlog()