Re: Race condition in FetchTableStates() breaks synchronization of subscription tables

vignesh C <vignesh21@gmail.com>

From: vignesh C <vignesh21@gmail.com>
To: Alexander Lakhin <exclusion@gmail.com>
Cc: "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2024-02-09T06:49:28Z
Lists: pgsql-hackers
On Thu, 8 Feb 2024 at 23:30, Alexander Lakhin <exclusion@gmail.com> wrote:
>
> 08.02.2024 12:25, vignesh C wrote:
> > Yes, the wakeup call sent by the "CREATE SUBSCRIPTION" command was
> > getting missed in this case. The wakeup call can be sent during
> > subscription creation/modification and when the apply worker exits.
> > WaitForReplicationWorkerAttach should not reset the latch here as it
> > will end up delaying the apply worker to get started after 180 seconds
> > timeout(DEFAULT_NAPTIME_PER_CYCLE). The attached patch does not reset
> > the latch and lets ApplyLauncherMain to reset the latch and checks if
> > any new worker or missing worker needs to be started.
>
> Thank you for the updated patch!
> I ran all the subscription tests in a loop (with the sleeps added as
> before) and observed no failures and 180+ seconds duration.

Thanks, I have created the following Commitfest entry for this:
https://commitfest.postgresql.org/47/4816/

Regards,
Vignesh



Commits

  1. Fix the missing table sync due to improper invalidation handling.