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

[Victor Pascual Ávila]

On Wed, May 27, 2009 at 10:57 AM, Pascal Maugeri
<pascal.maugeri at gmail.com> wrote:
> 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 ?


To my best knowledge, TCP support in Kamailio is blocking. This has
been addressed for sip-router (tcp_async=yes). Anyway, there are still
some issues for tls.

How many simultaneous TCP connections are you handling? You could try
to limit the max number of connections and check the impact on the CPU
consumption.

Cheers,
-- 
Victor Pascual Ávila