On Fri, 2023-01-20 at 08:56 +0000, Abhishek Prakash wrote:
> We are facing below issue with read replica we did work arounds by setting
> hot_standby_feedback, max_standby_streaming_delay and max_standby_archive_delay,
> which indeed caused adverse effects on primary DB and storage. As our DB is
> nearly 6 TB which runs as AWS Postgres RDS.
>
> Even the below error occurs on tables where vacuum is disabled and no DML
> operations are permitted. Will there be any chances to see row versions
> being changed even if vacuum is disabled.
> Please advise.
>
> 2023-01-13 07:20:12 UTC:10.64.103.75(61096):ubpreplica@ubprdb01:[17707]:ERROR: canceling statement due to conflict
withrecovery
> 2023-01-13 07:20:12 UTC:10.64.103.75(61096):ubpreplica@ubprdb01:[17707]:DETAIL: User query might have needed to see
rowversions that must be removed.
It could be HOT chain pruning or an anti-wraparound autovacuum (which runs
even if autovacuum is disabled).
Disabling autovacuum is not a smart idea to begin with.
Your best bet is to set "max_standby_streaming_delay = -1".
More reading:
https://www.cybertec-postgresql.com/en/streaming-replication-conflicts-in-postgresql/
Yours,
Laurenz Albe