lkml.org 
[lkml]   [2000]   [Oct]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: syslog() blocks on glibc 2.1.3 with kernel 2.2.x
From
Date
Ricky Beam <jfbeam@bluetopia.net> writes:

> Personally, I'd look closely at your setup to determine exactly why
> this has become a problem. named is being blocked on writing to
> /dev/log. This should only happen if there is sufficient _local_
> syslog traffic to fill the buffer or syslogd has too much remote
> traffic to ever read from /dev/log.

There is a lot of local traffic as well, yes.

Lots of local traffic means named eventually finds itself waiting in
line to log. Lots of remote traffic means syslogd is trying to talk
to named a lot (to do reverse lookups). named waiting in line +
syslogd trying to talk to named == deadlock; this is not too hard to
see.

Once the name resolution times out, you might expect things to become
unstuck. But they don't.

Perhaps syslogd is not giving higher priority to local messages; if it
did, maybe it could recover from the deadlock. But this would not be
a reliable solution; the only reliable solution is for syslogd to be
independent of any processes which need to talk to it.

> Per chance are you running the name service caching daemon (nscd)?

No.

> I'd also guess you aren't disabling fsync() for your sysylog files
> (it's part of the syslog.conf format) -- this is a conciderable
> drain on syslogd.

I see no documentation for such an option in the syslog.conf man page.
This is with the current Red Hat 6.2 syslogd (package
sysklogd-1.3.31-17).

- Pat
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 12:41    [W:0.073 / U:12.840 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site