Horton

Re: Use standard SIGHUP and SIGTERM handlers in autoprewarm module

Fujii Masao <masao.fujii@oss.nttdata.com>

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From: Fujii Masao <masao.fujii@oss.nttdata.com>
To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>, bharath.rupireddyforpostgres@gmail.com
Cc: pgsql-hackers@postgresql.org
Date: 2020-11-10T09:34:44Z
Lists: pgsql-hackers

Attachments


On 2020/11/10 16:17, Kyotaro Horiguchi wrote:
> At Sat, 7 Nov 2020 19:31:21 +0530, Bharath Rupireddy <bharath.rupireddyforpostgres@gmail.com> wrote in
>> The main reason for having SetLatch() in
>> SignalHandlerForConfigReload() is to wake up the calling process if
>> waiting in WaitLatchOrSocket() or WaitLatch() and reload the new
>> config file and use the reloaded config variables. Maybe we should
>> give a thought on the scenarios in which the walreceiver process
>> waits, and what happens in case the latch is set when SIGHUP is
>> received.
> 
> The difference is whether the config file is processed at the next
> wakeup (by force-reply-request or SIGTERM) of walreceiver or
> immediately. If server-reload happened frequently, say, several times
> per second(?), we should consider to reduce the useless reloading, but
> actually that's not the case.

So, attached is the patch that makes walreceiver use both standard
SIGTERM and SIGHUP handlers. Currently I've not found any actual
issues by making walreceiver use standard SIGHUP handler, yet.

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION

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.