[Kamailio-Users] tcp_blocking_connect related errors and Kamailio using 100% CPU

[Iñaki Baz Castillo]

2009/5/27 Pascal Maugeri <pascal.maugeri at gmail.com>:
> Hi
>
> Using Kamailio 1.5 we periodically get the following errors:
>
> Jul  1 09:54:41 localhost /usr/local/sbin/openser[3836]:
> ERROR:core:tcp_blocking_connect: poll error: flags 18
> Jul  1 09:54:41 localhost /usr/local/sbin/openser[3836]:
> ERROR:core:tcp_blocking_connect: failed to retrieve SO_ERROR (110)
> Connection timed out
> Jul  1 09:54:41 localhost /usr/local/sbin/openser[3836]:
> ERROR:core:tcpconn_connect: tcp_blocking_connect failed
> Jul  1 09:54:41 localhost /usr/local/sbin/openser[3836]:
> ERROR:core:tcp_send: connect failed
> Jul  1 09:54:41 localhost /usr/local/sbin/openser[3836]: ERROR:tm:msg_send:
> tcp_send failed
>
> They are several emails in this mailing list explaining we should play with
> tcp parameters. I will try to change my configuration and see if we can
> solve this issue.
>
> But when this kind of error happen we observe that the kamailio processes
> are using 100% of CPU (top).
>
> Our client is using SIP over TCP only (no UDP).
>
> Do you have any hint on how to configure Kamailio to improve TCP support ?
> Is it normal to kamailio processes to overload CPU ?

Unfortunatelly a kamailio TCP listeners blocks when initiates a
outgoing TCP connection. If it fails, you get a kamailio process
"stopped" waiting for that connection to end. If you have 8 kamailio
TCP listeners and have this issue in all of them, Kamailio cannot
handle TCP connection for a while.

This is of course something that should change radically (there have
been already threads about this issue). However I've ever seen CPU at
100% due to this issues. How many concurrent TCP connection does your
kamailio handle when it occurs?

-- 
Iñaki Baz Castillo
<ibc at aliax.net>