Re:Postgres, Kafka, and a mysterious 100 GB
by mattashii on Tuesday December 07, 2021 @08:01PM
(#29480188)
Yes, but this system seems to have generated WAL at a very high rate for something that is a test system with no load.
It went from effectively 0 to 97 GB in less than 6 days; which is 673 MB/hr; 11MB /min, or 58 MB /checkpoint timer.
If we consider that most, if not all, of this traffic would be based on checkpoint-related full-page writes, that's still some 7000 distinct pages being modified every 5 minutes. Even when I consider pg_stat_statements recording and writing out all activities, modifying ~7000 blocks is a lot for what I can expect to be repeating and templated maintenance tasks.
It went from effectively 0 to 97 GB in less than 6 days; which is 673 MB/hr; 11MB /min, or 58 MB /checkpoint timer.
If we consider that most, if not all, of this traffic would be based on checkpoint-related full-page writes, that's still some 7000 distinct pages being modified every 5 minutes. Even when I consider pg_stat_statements recording and writing out all activities, modifying ~7000 blocks is a lot for what I can expect to be repeating and templated maintenance tasks.