Re: Use standard SIGHUP and SIGTERM handlers in autoprewarm module

Kyotaro Horiguchi <horikyota.ntt@gmail.com>

From: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
To: bharath.rupireddyforpostgres@gmail.com
Cc: masao.fujii@oss.nttdata.com, pgsql-hackers@postgresql.org
Date: 2020-11-05T03:12:06Z
Lists: pgsql-hackers
At Wed, 4 Nov 2020 21:16:29 +0530, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> wrote in 
> On Wed, Nov 4, 2020 at 2:36 PM Fujii Masao <masao.fujii@oss.nttdata.com> wrote:
> >
> > Regarding other two patches, I think that it's better to use MyLatch
> > rather than MyProc->procLatch or walrcv->latch in WaitLatch() and
> > ResetLatch(), like other code does. Attached are the updated versions
> > of the patches. Thought?
> >
> 
> +1 for replacing MyProc->procLatch with MyLatch in the autoprewarm
> module, and the patch looks good to me.

Looks good to me, too.

> I'm not quite sure to replace all the places in the walreceiver
> process, for instance in WalRcvForceReply() we are using spinlock to
> acquire the latch pointer and . Others may have better thoughts on
> this.

The SIGTERM part looks good. The only difference between
WalRcvSigHupHandler and SignalHandlerForConfigReload is whether latch
is set or not.  I don't think it's a problem that config-reload causes
an extra wakeup.  Couldn't we do the same thing for SIGHUP?

We might even be able to reload config file in
ProcessWalRcvInterrupts().

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center



Commits

  1. Revert "Get rid of the dedicated latch for signaling the startup process".

  2. Improve log message about termination of background workers.

  3. Use standard SIGTERM signal handler die() in test_shm_mq worker.

  4. Use standard SIGHUP and SIGTERM signal handlers in worker_spi.

  5. Use standard SIGHUP and SIGTERM handlers in walreceiver.

  6. pg_prewarm: make autoprewarm leader use standard SIGHUP and SIGTERM handlers.

  7. Get rid of the dedicated latch for signaling the startup process.

  8. Use standard SIGHUP handler in syslogger.

  9. Use PostgresSigHupHandler in more places.

  10. Fix race condition with unprotected use of a latch pointer variable.

  11. Remove remnants of ImmediateInterruptOK handling.

  12. Introduce Streaming Replication.