Thread: Re: Documentation update of wal_retrieve_retry_interval to mention table sync worker
Re: Documentation update of wal_retrieve_retry_interval to mention table sync worker
From
Peter Smith
Date:
On Thu, Dec 26, 2024 at 1:37 AM vignesh C <vignesh21@gmail.com> wrote: > > Hi, > > Currently, we restart the table synchronization worker after the > duration specified by wal_retrieve_retry_interval following the last > failure. While this behavior is documented for apply workers, it is > not mentioned for table synchronization workers. I believe this detail > should be included in the documentation for table synchronization > workers as well. Attached is a patch to address this omission. > > Regards, > Vignesh Hi Vignesh, Here are some review comments for your v1 patch. +1 to enhance the documentation. ====== 1. <para> In logical replication, this parameter also limits how often a failing - replication apply worker will be respawned. + replication apply worker, and table synchronization worker will be + respawned. </para> /, and/or/ SUGGESTION In logical replication, this parameter also limits how often a failing replication apply worker or table synchronization worker will be respawned. ====== 2. I think the reader might never be aware of any of this (throttled relaunch) behaviour unless they accidentally stumble across the docs for this GUC, so IMO this information should be mentioned elsewhere -- wherever the tablesync worker errors are documented. But, TBH, I can't find anywhere in the PostgreSQL docs where it even mentions re-launching failed tablesync workers! Anyway, I think it might be good to include such information in some suitable place (maybe in the CREATE SUBSCRIPTION notes? or maybe in Chapter 29?) to say something like... SUGGESTION: In practice, if a table synchronization worker fails during logical replication, the apply worker detects the failure and attempts to respawn the table synchronization worker to continue the synchronization process. This behaviour ensures that transient errors do not permanently disrupt the replication setup. See also wal_retrieve_retry_interval. ====== Kind Regards, Peter Smith. Fujitsu Australia