> Date: Fri, 12 Aug 2005 16:11:11 -0400
> From: Sven Willenberger <sven at dmv.com>
> Subject: [Slony1-general] Slony appears to restart every 11 minutes
> 	and log	rotation
> To: slony1-general at gborg.postgresql.org
Message-ID: <1123877471.5149.35.camel at lanshark.dmv.com>
> 
> I have been banging my head over slony log rotation for quite some
> time now and I am at a loss. Here is the situation:
> 
> I have 2 ways I can start slony:
> 1) su slony -c "/usr/local/bin/slon -p /var/run/slon/slon.pid -d 2
> T1 dbname=thedb > /usr/local/etc/slony/slony.out 2>&1 &"
> 2) su slony -c "/usr/local/bin/slon -f /usr/local/etc/slon.conf
> > /dev/null 2>&1 &"
> 
> Both of these methods will start up slon, background it so as not to
> spew messages to console and get tied to tty, and log it (either to
> the slony.out file in case #1, or /var/log/slony.log via syslog in > >
> case #2).
> 
> With method 1, if I use newsyslog to rotate slony.out (or manually
> rotate it), issuing a kill -HUP to to /var/run/slon/slon.pid
> restarts the process but it will not log to the new file, it actually
logs to slony.out.0 -- i.e. it appears to latch onto the inode number of
the logfile and will not renew it during a sighup. 

This is true: if you redirect output, the SHELL opens your .out file,
once, and slon doesn't even know the name of that file. 
 
> With method 2, I seem to have a case whereby slon is not aware of
> its listeners or something similar and keeps "restarting":
> Aug 12 11:52:09 server slon[89926]: [29-16] CONFIG main: slon
> version
> 1.1.0 starting up
> Aug 12 11:52:09 server slon[89926]: [30-16] CONFIG main: slon
...
> Also, with method 2, at each restart interval the number of entries
> of
> "cleanupThread" increases by one; i.e. after the first restart, 2
> cleanupThread entries, the next restart had 4, the next had 6, the
> next
> restart had 8 and so on. 
Now that looks like a real bug.

> Either way, at the moment I have no automagic way of
> rotating
> logfiles that does not end up in some anomalies. Any ideas here?

Since you're happy with logging by redirecting output to a file, I'll
assume the following is acceptable ...

If you want, you can implement log rotation with a one-line shell
script. Something like this (I have no Unix box at the moment to test
this first, so bear with me on typos):

$ (slon ... | while read; do echo $REPLY >mylog.$(date +%W); done) &

(If I recall correctly, "date +%W" returns the day-of-the-week. Choose
your granularity and cycle as you will; a new log every hour, for the
last 30 days.
slon doesn't log so much stuff (at -d0) that opening a file per line is
a real kill. If you feel that's a concern, post again, and I'll post a
small "C" program that does the rotation.