Since I am using pg_wal_replay_pause before my pg_dump, it doesn't throw any error. Instead, it waits for the resource to release the lock so that it can proceed with taking the dump. the hot_standby_feedback is set to on
I am facing some problems while taking logical backup of my database using pg_dump. We have set up our infrastructure such that the logical backups are taken on our DR. Our intention here is to avoid substantial load on our primary server. We also pause and play wal files using pg_wal_replay_pause and pg_wal_replay_resume before and after pg_dump. However, at the time of pausing the wal replay, if there is a table under ACCESS SHARE MODE, the pg_dump cannot complete the backup.
Can anyone suggest any better solution to take a logical backup using pg_dump where the table lock doesn't result in failure of the logical backup?
Hi Viral, what's the error pg_dump is throwing at you ? what's the current setting of standby_feedback in your replica?
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El genio es 1% inspiración y 99% transpiración. Thomas Alva Edison
Nothing off the top of my head that could explain this behavior, if possible, try disabling hot_standby_feedback on the replica (in the master it has no effect) for a bit and see if that helps. Access share mode kind of locks shouldn't interfere with pg_dump, are both master and slave the exact same versions including the minor releases? it might be a bug, try upgrading to the latests minor releases in both ends. Since when did you start seeing this behavior, how long have you been on PG10 and creating backups this way? any recent modification in configurations?
Since you're using PG10, you could try logical replication, it's more reliable for this sort of thing, since the activity on the master doesn't affect the slave lock-wise whatsoever.
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El genio es 1% inspiración y 99% transpiración. Thomas Alva Edison
Also, check for the occurrence of long running transactions on the master. Does the replica serve as a data source for analytic applications (reports) ?
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El genio es 1% inspiración y 99% transpiración. Thomas Alva Edison