postgres data-observability - default startup lookback to 300s, trim description

Bumps cron startup recovery window from 60s to 5 minutes (300s) so longer
scheduler gaps don't drop fires, and removes the implementation-specific
note about the Cluster Agent rebalancing pods from the user-facing config
description.

Signed-off-by: mobuchowski <maciej.obuchowski@datadoghq.com>

Author: mobuchowski

postgres/assets/configuration/spec.yaml

@@ -602,14 +602,12 @@ files:
             Lookback window for cron-scheduled queries on check startup. If the
             most recent scheduled tick was within this many seconds before the
             check started, the query fires immediately on startup to recover
-            fires that may have been lost across a check restart (for example,
-            when the Cluster Agent rebalances checks across pods). Larger
-            values trade higher duplicate-fire rate for fewer missed fires.
+            fires that may have been lost across a check restart.
             Set to 0 to disable startup recovery.
           value:
             type: integer
-            example: 60
-            display_default: 60
+            example: 300
+            display_default: 300
         - name: run_sync
           hidden: true
           description: Run the job synchronously (for testing).

postgres/datadog_checks/postgres/data/conf.yaml.example

@@ -465,16 +465,14 @@ instances:
         #
         # collection_interval: 10
 
-        ## @param cron_startup_lookback_seconds - integer - optional - default: 60
+        ## @param cron_startup_lookback_seconds - integer - optional - default: 300
         ## Lookback window for cron-scheduled queries on check startup. If the
         ## most recent scheduled tick was within this many seconds before the
         ## check started, the query fires immediately on startup to recover
-        ## fires that may have been lost across a check restart (for example,
-        ## when the Cluster Agent rebalances checks across pods). Larger
-        ## values trade higher duplicate-fire rate for fewer missed fires.
+        ## fires that may have been lost across a check restart.
         ## Set to 0 to disable startup recovery.
         #
-        # cron_startup_lookback_seconds: 60
+        # cron_startup_lookback_seconds: 300
 
     ## @param pg_stat_statements_view - string - optional - default: pg_stat_statements
     ## Set this value if you want to define a custom view or function to allow the datadog user to query the

postgres/datadog_checks/postgres/data_observability.py

@@ -21,7 +21,7 @@
 # Cap the number of rows fetched per query to prevent unbounded memory usage.
 MAX_RESULT_ROWS = 10_000
 
-DEFAULT_CRON_STARTUP_LOOKBACK_SECONDS = 60
+DEFAULT_CRON_STARTUP_LOOKBACK_SECONDS = 300
 
 
 class PostgresDataObservability(DBMAsyncJob):

postgres/tests/test_data_observability.py

@@ -880,7 +880,7 @@ def _make_cron_lookback_check(pg_instance, lookback_seconds, queries=None):
 
 def test_cron_startup_lookback_recovers_missed_fire(pg_instance, aggregator, monkeypatch):
     """A first-sight cron query whose previous tick falls within the lookback window fires immediately."""
-    # 00:50:10 — 10s after the 00:50 tick, well inside the default 60s lookback window.
+    # 00:50:10 — 10s after the 00:50 tick, well inside the default 300s lookback window.
     current_time = [float(_BASE_EPOCH + 70)]
     monkeypatch.setattr('datadog_checks.postgres.data_observability.time.time', lambda: current_time[0])
 
@@ -909,8 +909,8 @@ def test_cron_startup_lookback_disabled_skips_recovery(pg_instance, aggregator,
 
 def test_cron_startup_lookback_outside_window_skips(pg_instance, aggregator, monkeypatch):
     """A pod starting well past the lookback window does not over-fire."""
-    # 00:51:30 — 90s after the 00:50 tick, beyond the default 60s lookback.
-    current_time = [float(_BASE_EPOCH + 150)]
+    # 00:55:40 — 340s after the 00:50 tick, beyond the default 300s lookback.
+    current_time = [float(_BASE_EPOCH + 400)]
     monkeypatch.setattr('datadog_checks.postgres.data_observability.time.time', lambda: current_time[0])
 
     mock_conn, _ = _make_mock_conn()