[syslog-ng] syslog-ng 2.0.4 hang

[Balazs Scheidler]

On Tue, 2007-07-17 at 15:20 +0100, Geller, Sandor (IT) wrote:
> > Hi,
> > 
> > I've encountered a strange problem. I'm using syslog-ng 2.0.4 with
> > a fairly basic setup, and syslog-ng hangs when it is reading from
> > /proc/kmsg, but only right after boot and only on one of my machines,
> > which is a RHEL AS3 machine.
> > 
> > It is reproducible, the host hangs on every boot as every process
> > which tries to write to /dev/log gets blocked.
> > 
> > Has anyone seen such behaviour?
> 
> Replying to myself: adding log_fetch_limit(1) for the /proc/kmsg source
> solved the issue.

Hmm... this should not be happening, the file() source does not use
fetch_limit(), it basically forces the use of a single read system call.
(by using the LR_NOMREAD flag)

This was implemented before 1.9.11, so it's been a long time, since this
is integrated.

Are you sure this was the cause? Can you check if syslog-ng actually
issues multiple read() system calls without checking for readability?

-- 
Bazsi