Logging autovacuum and vacuum activities (original) (raw)

Information about autovacuum activities is sent to the postgresql.log based on the level specified in the rds.force_autovacuum_logging_level parameter. Following are the values allowed for this parameter and the PostgreSQL versions for which that value is the default setting:

• disabled (PostgreSQL 10, PostgreSQL 9.6)
• debug5, debug4, debug3, debug2,debug1
• info (PostgreSQL 12, PostgreSQL 11)
• notice
• warning (PostgreSQL 13 and above)
• error, log, fatal, panic

The rds.force_autovacuum_logging_level works with thelog_autovacuum_min_duration parameter. Thelog_autovacuum_min_duration parameter's value is the threshold (in milliseconds) above which autovacuum actions get logged. A setting of -1 logs nothing, while a setting of 0 logs all actions. As withrds.force_autovacuum_logging_level, default values forlog_autovacuum_min_duration are version dependent, as follows:

• 10000 ms – PostgreSQL 14, PostgreSQL 13, PostgreSQL 12, and PostgreSQL 11
• (empty) – No default value for PostgreSQL 10 and PostgreSQL 9.6

We recommend that you set rds.force_autovacuum_logging_level toWARNING. We also recommend that you setlog_autovacuum_min_duration to a value from 1000 to 5000. A setting of 5000 logs activity that takes longer than 5,000 milliseconds. Any setting other than -1 also logs messages if the autovacuum action is skipped because of a conflicting lock or concurrently dropped relations. For more information, see Automatic Vacuuming in the PostgreSQL documentation.

To troubleshoot issues, you can change the rds.force_autovacuum_logging_level parameter to one of the debug levels, from debug1 up to debug5 for the most verbose information. We recommend that you use debug settings for short periods of time and for troubleshooting purposes only. To learn more, see When to log in the PostgreSQL documentation.

Note

PostgreSQL allows the rds_superuser account to view autovacuum sessions inpg_stat_activity. For example, you can identify and end an autovacuum session that is blocking a command from running, or running slower than a manually issued vacuum command.