[asterisk-users] Re: unable to get channel lock BAD BAD BAD

[BJ Weschke]

 On 11/16/06, Tim Uckun <timuckun at gmail.com> wrote:
> > 98% of the people here don't use Trixbox.
>
>
> I don't think this is something with trixbox. I asked the person
> having the same problem as me if he was using trixbox to see if that
> would narrow down the realm of the problem.
>
> Anyway the error message is in the asterisk log.   Googling around I
> see that other people have posted the problem and nobody has gotten an
> answer.

 Steve provided an answer on this guys earlier in the thread.
Basically what's happening is that Asterisk is getting a SIP message
to do something with a call whose channel lock is still being held by
something else within Asterisk. It could be a bad application, it
could be any number of other things. The only reason you're seeing
such an error now is because before chan_sip would go into race
state/infinite loop trying to acquire a lock that possibly could never
be acquired (because we don't know who has the lock and for what
reason).
 Our (my) thought in adding it earlier this summer was that in the
case where a SIP channel was in bad shape and locks were being held,
it was probably better for us to act like we never received the SIP
message to the client, log the issue, and hopefully by the time the
sender of the message went for a retransmit (since SIP msgs in * only
come in via UDP and when we don't respond, one must retransmit
assuming the original msg never got there), the lock condition would
clear itself and things could process as normal.

 It's funny this thread came up today though as I have a client who's
actually never seen this msg before on any of their production systems
and all of a sudden it came up this evening on one of them and
actually brought chan_sip to a halt. Is there something environmental
that's come to light of late that might be causing this? It certainly
begs further investigation in my mind.

 For those that are getting this msg, a first step at troubleshooting
would be to try to figure out what application the given channel whose
lock cannot be acquired is in by way of looking at the logs or (if
you're lucky enough for it to function with the system in this state)
a "show channels".

 BJ

-- 
Bird's The Word Technologies, Inc.
http://www.btwtech.com/