[tpop3d-discuss] How do i change the syslog facility?
Paul Makepeace
Paul.Makepeace at realprogrammers.com
Wed, 7 Nov 2001 15:52:58 -0800
On Wed, Nov 07, 2001 at 11:42:42PM +0000, Chris Elsworth wrote:
> A busy mail server might spend almost as much time (remember ISPs turn
> logging up to aid in troubleshooting, coping for customer complaints, etc)
> logging as it does sending mail when going via syslogd.
>
> A real life example. Demon use thttpd (a very lightweight httpd server)
> for Homepages. Output from top with irrelevant processes snipped:
>
> PID USERNAME THR PRI NICE SIZE RES STATE TIME CPU COMMAND
> 24110 nobody 1 49 0 51M 18M run 549.2H 12.94% thttpd
> 15207 root 18 58 0 4608K 1824K sleep 82.8H 1.57% syslogd
I'm curious -- is the machine that is logging the syslog messages also
the same machine that is writing data to a file somewhere? Typically a
busy system will have a dedicated syslogging facility that has its own
optimi[sz]ed resources (disk, cpu, etc). That is typically one of
the major plus points of syslog after all is its ability to
centrali[sz]e logging.
> Notice the runtime on each process. syslogd takes up a substantial amount
> of CPU time - for this reason we're looking at moving to direct file
> logging. One line (about 100 bytes) is logged per hit.
Have you looked at disk contention, profiled/straced syslogd and checked
for filesystem fragmentation?
I'm not saying syslog is the panacea but I've often seen it blamed where
it wasn't really the main culprit, more of a pest that spits while
others are throwing rocks.
Paul