Socket leak (Was: Re: What triggers "No Buffer Space) ?Available"?

[Marc G. Fournier]

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- --On Tuesday, May 08, 2007 15:14:29 +0200 Oliver Fromme 
<olli at lurza.secnetix.de> wrote:

> What kind of jails are those?  What applications are
> running inside them?  It's quite possible that the
> processes on one machine use 120 sockets per jail,
> while on a different machine they use only half that
> many per jail, on average.  Of course, I can't tell
> for sure without knowing what is running in those
> jails.

The all run pretty much the same thing, on all the machines ... by default, 
standard syslog, sshd, cron, cyrus imapd, postfix and apache ... some run 
aolserver over top of that, or jdk/tomcat, or zope ... but they aren't specific 
to the server itself, as they get moved around ...

>  > kern.ipc.numopensockets: 7400
>  > kern.ipc.maxsockets: 12328
>  >
>  > ps looks like:
>  >

<stuff deleted>

> 2368  p2  Is+  Sat01PM   0:00.03 /bin/tcsh  > root    2112  0.0  0.1  5220
> 2360  p3  Ss+  Sat01PM   0:00.04 /bin/tcsh  > root   91221  0.0  0.1  5140
> 2440  p4  Ss+  11:49PM   0:00.12 -tcsh (tcsh)
>
> I don't think those processes should consume 7400 sockets.
> Indeed, this really looks like a leak in the kernel.

Robert has sent me a suggestion to try that I'm in the process of putting 
together right now, involving backing out some work on uipc_usrreg.c ...


> Maybe "sockstat -u" and/or "fstat | grep -w local" (both
> of those commands should basically list the same kind of
> information).  My guess is that the output will be rather
> short, i.e. much shorter than 7355 lines.  If that's true,
> it is another indication that the problem is caused by
> a kernel leak.

at the time I rebooted, with no processes, but 7400 sockets:

> wc -l sockstat.out.txt
      12 sockstat.out.txt
> grep local fstat.out.txt | wc -l
       7

- ----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email . scrappy at hub.org                              MSN . scrappy at hub.org
Yahoo . yscrappy               Skype: hub.org        ICQ . 7615664
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