[OpenSIPS-Users] MediaProxy loading issues - I think I need some tuning here

[Saúl Ibarra Corretgé]

Hi,

On Apr 5, 2012, at 10:51 PM, Jock McKechnie wrote:

> Thank you for your suggestions;
> 
> I have noticed a very strange symptom but I've yet to determine if it
> actually affects call handling or not. When the -relay is heavily
> loaded it'll have the load spread out across the cores and then,
> suddenly, the CPU usage appears to drift over to a single core and max
> it out for a bit, with the other cores doing nothing.... and then it
> all spreads out again. The heavier loaded it is, the more time it
> spends on one core. Very strange. I installed irqbalance but it
> appears not to make a difference.
> 

If you are bombarding the server with calls continuously, you could see a CPU spike, since the call setup is done in a single thread, but after the conntrack rule has been created the kernel takes care and load is shared across all cores. Though I have never experienced this.

> I'm hoping the worst this may cause is a slight delay in a call
> starting up with an allocated pair of media ports in iptables
> forwarding, rather than call audio distortion. Have you ever seen
> anything like this?
> 

Since MediaProxy doesn't 'touch' the actual media I don't think it can cause distortion. Now, if the system is so overloaded that packets can't leave the server 'on time', you may have jitter issues. This is just a hypothesis, because it would mean that your server is so overloaded that even sending some UDP data is a problem...


Regards,

--
Saúl Ibarra Corretgé
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