Re: logs of postgresql and pid-stamping. possible

On Thu, 2002-08-15 at 13:13, Tom Lane wrote:
> Andrew Sullivan <andrew@libertyrms.info> writes:
> > Yes, but all that stuff with the ! at the beginning is associated
> > with the LOG: QUERY STATISTICS ahead of it, no?  Isn't that enough of
> > a separator to make it clear?  Or am I missing something (likely)?
>
> He's concerned about query stats printed by concurrent backends becoming
> interleaved in the log file.  A fair concern, but I don't think it's
> real, at least not since 7.2.
>
> As of 7.2, the whole multiline stats message will be written in a
> single write() call, so I'd be pretty surprised if it got interleaved
> with other processes' messages.  At least on HPUX, this is guaranteed
> not to happen when stderr is a pipe, so if you're piping the postmaster
> log to some kind of log rotation script then it ought to be quite safe.
> Possibly if the log is a plain disk file there might be trouble on some
> kernels.
>
> If you're logging via syslog() then it's a different story: each line is
> sent to syslog individually, I believe.  But syslog already marks each
> line with PID.
and with multi-line messages, it gives a message number-line number tag
as well.  (I remember putting in the smarter breakup code in 7.1
(IIRC)).

LER


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Larry Rosenman                     http://www.lerctr.org/~ler
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