[SR-Users] Kamailio propagates 180 and 200 OK OUT OF ORDER

[Alex Balashov]

On Wed, Apr 08, 2020 at 04:54:48PM +0100, David Villasmil wrote:

> I have a question on this, since 180 arrived before the 200, shouldn’t it
> go out before? I.e.: FIFO? Or is this not happening because there are
> multiple processes and one may take the 180 and the other the 200 and they
> are processes independently?
> 
> I guess setting the childs to only 1 should prove this theory.

In theory, it should all be FIFO, of course. In practice, there are
stochastic aspects to OS process scheduling and I/O scheduling which
make the ingress and egress of messages arriving at Kamailio
simultaneously or substantially simultaneously somewhat indeterminate.

And, of course, it depends on how complicated the processing of the
messages respectively is, either in computational terms, or external I/O
wait, or both. 

To Steve Davies' point, that's just the nature of the multiprocess
architecture, together with the lack of a distributor thread.

-- Alex

-- 
Alex Balashov | Principal | Evariste Systems LLC

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