collect_buffercache_metrics crashes DB on PostgresSQL Aurora 17

[billoneil]

I don't believe this is an issue with DataDog's agent but it might be worth updating documentation / adding a note that this is a potential issue.

I have an open support ticket with AWS and will follow up if I get more details.

postgresql.log.2025-10-11-1300:2025-10-11 13:48:17 UTC::@:[596]:LOG:  server process (PID 1031) was terminated by signal 7: Bus error

More logs

postgresql.log.2025-10-11-1300:2025-10-11 13:48:17 UTC::@:[596]:LOG:  server process (PID 1031) was terminated by signal 7: Bus error
postgresql.log.2025-10-11-1300-2025-10-11 13:48:17 UTC::@:[596]:DETAIL:  Failed process was running: /* service='datadog-agent' */ WITH buffer_by_relfilenode AS (
postgresql.log.2025-10-11-1300-	    SELECT reldatabase, relfilenode,
postgresql.log.2025-10-11-1300-	        NULLIF(COUNT(CASE WHEN relfilenode IS NOT NULL THEN 1 END), 0) as used,
postgresql.log.2025-10-11-1300-	        COUNT(CASE WHEN relfilenode IS NULL THEN 1 END) as unused,
postgresql.log.2025-10-11-1300-	        SUM(usagecount) as sum_usagecount,
postgresql.log.2025-10-11-1300-	        NULLIF(SUM(isdirty::int), 0) as sum_dirty,
postgresql.log.2025-10-11-1300-	        NULLIF(SUM(pinning_backends), 0) as sum_pinning
postgresql.log.2025-10-11-1300-	    FROM pg_buffercache
postgresql.log.2025-10-11-1300-	    GROUP BY reldatabase, relfilenode
postgresql.log.2025-10-11-1300-	)

Full Query

WITH buffer_by_relfilenode AS (
	    SELECT reldatabase, relfilenode,
	        NULLIF(COUNT(CASE WHEN relfilenode IS NOT NULL THEN 1 END), 0) as used,
	        COUNT(CASE WHEN relfilenode IS NULL THEN 1 END) as unused,
	        SUM(usagecount) as sum_usagecount,
	        NULLIF(SUM(isdirty::int), 0) as sum_dirty,
	        NULLIF(SUM(pinning_backends), 0) as sum_pinning
	    FROM pg_buffercache
	    GROUP BY reldatabase, relfilenode
	)
	SELECT COALESCE(d.datname, 'shared'), n.nspname, c.relname,
	       used, unused, sum_usagecount, sum_dirty, sum_pinning
	  FROM buffer_by_relfilenode b
	  LEFT JOIN pg_database d ON b.reldatabase = d.oid
	  LEFT JOIN pg_class c ON b.relfilenode = pg_relation_filenode(c.oid)
	  LEFT JOIN pg_namespace n ON n.oid = c.relnamespace;