Horton

Re: Wait event that should be reported while waiting for WAL archiving to finish

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Fujii Masao <masao.fujii@oss.nttdata.com>
Cc: Robert Haas <robertmhaas@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2020-02-17T09:48:57Z
Lists: pgsql-hackers 
On Mon, Feb 17, 2020 at 04:30:00PM +0900, Fujii Masao wrote:
> On 2020/02/14 23:43, Robert Haas wrote:
>> On Thu, Feb 13, 2020 at 10:47 PM Fujii Masao
>> <masao.fujii@oss.nttdata.com> wrote:
>>> Fixed. Thanks for the review!
>> 
>> I think it would be safer to just report the wait event during
>> pg_usleep(1000000L) rather than putting those calls around the whole
>> loop. It does not seem impossible that ereport() or
>> CHECK_FOR_INTERRUPTS() could do something that reports a wait event
>> internally.

CHECK_FOR_INTERRUPTS() would reset the event wait state.  Hm..  You
may be right about the WARNING and it would be better to not rely on
that.  Do you remember the states which may be triggered?

> OK, so I attached the updated version of the patch.
> Thanks for the review!

Actually, I have some questions:
1) Should a new wait event be added in recoveryPausesHere()?  That
would be IMO useful.
2) Perhaps those two points should be replaced with WaitLatch(), where
we would use the new wait events introduced?
--
Michael

Commits

  1. Add wait events for WAL archive and recovery pause.

  2. Add description about GSSOpenServer wait event into document.

  3. Add description about LogicalRewriteTruncate wait event into document.

  4. GSSAPI encryption support

  5. Create and use wait events for read, write, and fsync operations.