Re: [PORTS] Logging (was Re: PostgreSQL 7.0-2 RPMset released.)

Tom Lane wrote:
>
> Lamar Owen <lamar(dot)owen(at)wgcr(dot)org> writes:
> > The real problem with redirecting the postmaster output is the issue
> > of log rolling, which is impossible to do in the 'classic'
> > stderr/stdout redirect UNLESS you throw down postmaster when rolling
> > the log (unless you know a trick I don't).

I think I do ;-) read on...

> Yes. I think ultimately we will have to do some logging support code of
> our own to make this work the way we want. My thought at the moment is
> there's nothing wrong with logging to stderr, as long as there's some
> code somewhere that periodically closes stderr and reopens it to a new
> log file. There needn't be a lot of code involved, we just need a
> well-thought-out spec for how it should work. Comments anyone?
>
> regards, tom lane

I really enjoy using apache's rotatelogs program. stderr is
redirected through a pipe to a very small and robust C program,
rotatelogs, that takes as arguments number of seconds between
log rotates and the log filename. Logs are rotated every
argv[2] seconds. The rotatelogs program takes care of closing
and reopening, and nothing has to done from the application,
just start postmaster with '2>&1 | rotatelogs ...' at the end,
and log to stderr.

Also, BSD license! :)

For reference, I enclose the program as an attachment; it's
less than 100 lines. Also, here's the man page:

Name
rotatelogs - rotate Apache logs without having to kill
the
server

Synopsis
rotatelogs logfile rotationtime

Description
rotatelogs is a simple program for use in conjunction
with
Apache's piped logfile feature which can be used
like
this:

TransferLog "|rotatelogs
/path/to/logs/access_log
86400"

This creates the files /path/to/logs/access_log.nnnn
where
nnnn is the system time at which the log nominally
starts
(this time will always be a multiple of the rotation
time,
so you can synchronize cron scripts with it). At the
end
of each rotation time (here after 24 hours) a new log
is
started.

Options
logfile
The path plus basename of the logfile. The
suffix
.nnnn is automatically added.

rotationtime
The rotation time in seconds.

See Also
httpd(8)