[SR-Users] kamailio does not responde if an rtpengine is unreachable

[Daniel-Constantin Mierla]

I was able to figure out what could be the cause with:

modparam("rtpengine", "rtpengine_sock", "udp:127.0.0.1:2223
udp:192.168.64.4:2224")

Host 192.168.64.4 is not running (not existing in my case, just made up
that ip to be on the same network with the kamailio running on
192.168.64.2).

It was starting a slower, iterating over each child, but then all ok,
requests were handled very fast.

When I ran with:

modparam("rtpengine", "rtpengine_sock", "udp:127.0.0.1:2223
udp:127.0.0.1:2224")

with no rtpengine on port 2224, start was very fast, expecting to be due
to detecting very quickly that port was not open.

The cause for slower start was the code for ability to reload from
database. There are some locks that are enabled while initializing
rtpengine sockets, so each child had to wait for the one that acquired
the lock.

I pushed a quick fix for the case when db support is not enabled,
because these locks are useless in that case, so all children will do
the rtpengine init at the same time, without waiting for the others:

  *
https://github.com/kamailio/kamailio/commit/99250f758e6deb90a5852599f831a53ab394b751

Maybe you would also want to tune the timeout with the modparam:

modparam("rtpengine", "rtpengine_disable_tout", 5)

So detection of unavailable rtpproxy is fast, otherwise it is 60 sec by
default, so you may still experience some slow start per child process.

Once I get more time, I will optimize the reload from db as well, so the
build of rtpengine sockets is going to be done in parallel, by copying
first inside locking the addresses from shared memory to private (should
be fast) and then do the connect test  (which can be slower) outside of
locking.

I may also discovered an issue with reload from db, not sure if works
right now if there is the same number of rtpengine instances at reload.
But I need to verify if I understood the mechanism so far, not being the
one that coded db support and reload.

Cheers,
Daniel

On 26.12.18 10:59, Juha Heinanen wrote:
> Daniel-Constantin Mierla writes:
>
>> I tried quickly with a rtpengine that was not running, and kamailio
>> started fine and then was responding fast for sip requests.
>>
>> To clarify: you actually have more rtpengine configured (at least two)
>> in a set and one is not available, right?
> Yes, I have two in one set:
>
> udp:127.0.0.1:6050  (running)
> udp:192.26.134.10:6050 (host 192.26.134.10 is down)
>
>> Is the CPU usage very high? Because it is strange that is responding,
>> but with long delay ...
> top does not show any kamailio processes in the top.
>
> In addition to not responding to sip requests, kamailio does not respond
> to kamcmd command either.
>
> It stars to respond when rtpengine module gives up on trying and
> declares udp:192.26.134.10:6050 disabled.
>
> -- Juha

-- 
Daniel-Constantin Mierla -- www.asipto.com
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