Re: Race condition in recovery?

On Thu, May 20, 2021 at 10:21 PM Kyotaro Horiguchi
<horikyota(dot)ntt(at)gmail(dot)com> wrote:
> > > Conclusion:
> > > - I think now we agree on the point that initializing expectedTLEs
> > > with the recovery target timeline is the right fix.
> > > - We still have some differences of opinion about what was the
> > > original problem in the base code which was fixed by the commit
> > > (ee994272ca50f70b53074f0febaec97e28f83c4e).
> >
> > I am also still concerned about whether we understand in exactly what
> > cases the current logic doesn't work. We seem to more or less agree on
> > the fix, but I don't think we really understand precisely what case we
> > are fixing.
>
> Does the discussion above make sense?

I had trouble following it completely, but I didn't really spot
anything that seemed definitely wrong. However, I don't understand
what it has to do with where we are now. What I want to understand is:
under exactly what circumstances does it matter that
WaitForWALToBecomeAvailable(), when currentSource == XLOG_FROM_STREAM,
will stream from receiveTLI rather than recoveryTargetTLI?

--
Robert Haas
EDB: http://www.enterprisedb.com