Re: BUG #17103: WAL segments are not removed after exceeding max_slot_wal_keep_size

At Thu, 15 Jul 2021 14:22:35 +0900 (JST), Kyotaro Horiguchi <horikyota(dot)ntt(at)gmail(dot)com> wrote in
> At Wed, 14 Jul 2021 19:10:26 -0400, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote in
> > They should be, but they are not. That is the bug. They just hang
> > around, checkpoint after checkpoint. Some of them do get cleaned up, to
> > make up for new ones created during that cycle. It treats
> > max_slot_wal_keep the same way it treats wal_keep_size (but only if a
> > "lost" slot is hanging around). If you drop the lost slot, only then does
> > it remove all the accumulated WAL at the next checkpoint.
>
> Thanks! I saw the issue here. Some investigation showd me a doubious
> motion of XLogCtl->repliationSlotMinLSN. Slot invalidation is
> forgetting to recalculate it and that misbehavior retreats the segment
> horizon.
>
> So the attached worked for me. I'll repost the polished version
> including test.

This is it. It is for the master branch but also applicable to 14 as
is. Not needed for earlier version.
I believe the test works for Windows but haven't checked.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center