Re: Allow interrupts on waiting standby

From: Michael Paquier [mailto:michael(dot)paquier(at)gmail(dot)com]
> Oops, sorry for that, I quite mess up with this patch. The WaitLatch() call
> should still have WL_POSTMASTER_DEATH so as it can leave earlier, but yes
> I agree with your analysis that HandleStartupProcInterrupts() as this is
> part of the redo work.

Thank you, but did you remove WL_LATCH_SET from WaitLatch() intentionally? I understood you added it for startup process to respond quickly to events other than the postmaster death. Why don't we restore WL_LATCH_SET? I won't object to not adding the flag if there's a reason.

I'll mark this as ready for committer when I see WL_LATCH_SET added (optional) and you have reported that you did the following test cases:

* Startup process vanishes immediately after postmaster dies, while it is waiting for a recovery conflict to be resolved.

* Startup process vanishes immediately after "pg_ctl stop -m fast", while it is waiting for a recovery conflict to be resolved.

* Startup process resumes WAL application when max_standby_{archive | streaming}_delay is changed from the default -1 to a short period, e.g. 10s, and "pg_ctl reload" is performed, while it is waiting for a recovery conflict to be resolved.

> > Did Simon's committed patch solve the problem as expected?
>
> Does not seem so, I'll let Simon comment on this matter...

Agreed. I guess his patch for earlier releases should work if CHECK_FOR_INTERRUPTS() is replaced with HandleStartupProcInterrupts().

Regards
Takayuki Tsunakawa