[svlug] Re: syslog() gets blocked?

[Ira Abramov]

Quoting J C Lawrence, from the post of Mon, 06 Jan:
> > while trying to boot two machines at the same time I noticed one boots
> > and one doesn't. further investigation showed that after issuing one
> > of the an IP address, the DHCP server tries to record that fact in
> > syslog and gets blocked for about 35 seconds before it is freed to
> > serve the next machine.
> 
> I've seen this, not at the syslogd level but at the syslog(3) level (ie
> the syslog server is still responsive, its the client entry point which
> is not.  I've yet to conclusively debug this, but it has had all the
> flavours of a gethostbyname() (or similar) timeout to me.

unbelievably, that was the problem. a fix to resolv.conf did the trick.
what I can't understand is:

1. why would syslog try to do reverse resolving on a unix socket (not
TCP or UDP)
2. why it ignored /etc/hosts with the localhost entry.
3. why should the CLIENT block on this? the log line should be thrown in
the pipe and the syslog would read it once it got back from
gethostbyname()...

> ObNote: Check which version of syslogd you're using.  syslog-ng is strongly
> recommended, especially for log-hosts.

yeah, yeah, I told the system team that since I started studying the
system at this new job... it will take a while to change their design :)

-- 
Lord of the dance
Ira Abramov

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