Re: error context for vacuum to include block number

On Sat, Mar 28, 2020 at 6:46 AM Justin Pryzby <pryzby@telsasoft.com> wrote:
>
> On Sat, Mar 28, 2020 at 06:28:38AM +0530, Amit Kapila wrote:
> > > Hm, but I caused a crash *without* adding CHECK_FOR_INTERRUPTS, just
> > > kill+sleep.  The kill() could come from running pg_cancel_backend().  And the
> > > sleep() just encourages a context switch, which can happen at any time.
> >
> > pg_sleep internally uses CHECK_FOR_INTERRUPTS() due to which it would
> > have accepted the signal sent via pg_cancel_backend().  Can you try
> > your scenario by temporarily removing CHECK_FOR_INTERRUPTS from
> > pg_sleep() or maybe better by using OS Sleep call?
>
> Ah, that explains it.  Right, I'm not able to induce a crash with usleep().
>
> Do you want me to resend a patch without that change ?  I feel like continuing
> to trade patches is more likely to introduce new errors or lose someone else's
> changes than to make much progress.  The patch has been through enough
> iterations and it's very easy to miss an issue if I try to eyeball it.
>

I can do it but we have to agree on the other two points (a) I still
feel that switching to the truncate phase should be done at the place
from where we are calling lazy_truncate_heap and (b)
lazy_cleanup_index should switch back the error phase after calling
index_vacuum_cleanup.  I have explained my reasoning for these points
a few emails back.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com