Re: Patch to implement pg_current_logfile() function

On Wed, Feb 15, 2017 at 4:03 PM, Alvaro Herrera
<alvherre(at)2ndquadrant(dot)com> wrote:
> So what is going on here is that SysLogger_Start() wants to unlink the
> current-logfile file if the collector is not enabled. This should
> probably be split out into a separate new function, for two reasons:
> first, it doesn't seem good idea to have SysLogger_Start do something
> other than start the logger; and second, so that we don't have a syscall
> on each ServerLoop iteration. That new function should be called from
> some other place -- perhaps reaper() and just before entering
> ServerLoop, so that the file is deleted if the syslogger goes away or is
> not started.

I think it's sufficient to just remove the file once on postmaster
startup before trying to launch the syslogger for the first time.
logging_collector is PGC_POSTMASTER, so if it's not turned on when the
cluster first starts, it can't be activated later. If it dies, that
doesn't seem like a reason to remove the file. We're going to restart
the syslogger, and when we do, it can update the file.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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