Re: A failure of standby to follow timeline switch

On Sat, Jan 9, 2021 at 5:08 AM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
>
> Masao-san: Are you intending to act as committer for these? Since the
> bug is mine I can look into it, but since you already did all the
> reviewing work, I'm good with you giving it the final push.

Thanks! I'm thinking to push the patch.

> 0001 looks good to me; let's get that one committed quickly so that we
> can focus on the interesting stuff. While the implementation of
> find_in_log is quite dumb (not this patch's fault), it seems sufficient
> to deal with small log files. We can improve the implementation later,
> if needed, but we have to get the API right on the first try.
>
> 0003: The fix looks good to me. I verified that the test fails without
> the fix, and it passes with the fix.

Yes.

> The test added in 0002 is a bit optimistic regarding timing, as well as
> potentially slow; it loops 1000 times and sleeps 100 milliseconds each
> time. In a very slow server (valgrind or clobber_cache animals) this
> could not be sufficient time, while on fast servers it may end up
> waiting longer than needed. Maybe we can do something like this:

On second thought, I think that the regression test should be in
004_timeline_switch.pl instead of 001_stream_rep.pl because it's
the test about timeline switch. Also I'm thinking that it's better to
test the timeline switch by checking whether some data is successfully
replicatead like the existing regression test for timeline switch in
004_timeline_switch.pl does, instead of finding the specific message
in the log file. I attached the POC patch. Thought?

Regards,

--
Fujii Masao