Hi,
PostgreSQL version - 11.7
We are using wal-g for backup/restore. We had a duration of high WAL generation due to application usage due to which archive backup was delayed.
Backup was started through cron schedule and it didn't complete because it waits for the last WAL to be archived. Now, I know that long running transactions will prevent vacuuming of dead tuples but in this case we were able to run manual vacuums successfully but auto-vacuum never starts.
As soon as we terminated the long running backup session, the auto-vacuum started kicking in.
Wanted to understand why a backup operation is blocking the auto-vacuum?
Wal-g uses non-exclusive backups and waits for the last wal to be archived.
Thanks,
Nikhil