Horton

Re: [BUGS] Bug in Physical Replication Slots (at least 9.5)?

Michael Paquier <michael.paquier@gmail.com>

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From: Michael Paquier <michael.paquier@gmail.com>
To: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Cc: nag1010@gmail.com, jdnelson@dyn.com, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2017-08-28T11:14:54Z
Lists: pgsql-bugs, pgsql-hackers 
On Mon, Aug 28, 2017 at 8:02 PM, Kyotaro HORIGUCHI
<horiguchi.kyotaro@lab.ntt.co.jp> wrote:
> The first patch (0001-) fixes this problem, preventing the
> problematic state of WAL segments by retarding restart LSN of a
> physical replication slot in a certain condition.

FWIW, I have this patch marked on my list of things to look at, so you
can count me as a reviewer. There are also some approaches that I
would like to test because I rely on replication slots for some
infrastructure. Still...

+            if (oldFlushPtr != InvalidXLogRecPtr &&
+                (restartLSN == InvalidXLogRecPtr ?
+                 oldFlushPtr / XLOG_SEG_SIZE != flushPtr / XLOG_SEG_SIZE :
+                 restartLSN / XLOG_BLCKSZ != flushPtr / XLOG_BLCKSZ))
I find such code patterns not readable.
-- 
Michael

Commits

  1. Fix scenario where streaming standby gets stuck at a continuation record.