[Spce-user] kamailio-proxy.log error - mysql lost connection

Andreas Granig agranig at sipwise.com
Tue May 28 10:07:36 EDT 2013


Hi,

On 05/28/2013 03:42 PM, Matthew Ogden wrote:
> I realise with high IO load, things will timeout, but I would assume
> that the components of SPCE have a method for dealing with this:
>
> 1)Stop new registrations (without banning unless the frequency is too
> high -  a legitimate ban that may have been the cause of highio)
>
> 2)Honour existing registrations
>
> 3)Prioritise call tear downs
>
> 4)Because the thread happens synchronously for call tearups, and these
> will be timing out, reply with a 503 or similar code before the final
> timeout if unable to log data fast enough. Then log the timeout in
> waitable / (and discardable if necessary) thread?
>
> “Crashing” is not really an option for a SIP server, current calls
> should be more important than new calls etc. Current registrations and
> re-registrations more important than new ones and so forth.

None of the above options are really viable. A SIP message has to be 
received and parsed, and you'd want kamailio to somehow queue and 
re-order them based on the type. This is not something kamailio can do, 
and I'm not aware of any plans for them implementing such a thing.

On the other hand, there is nothing which makes a SIP server more 
special than a web server, the technical concept is really the same. If 
you have critical web sites (like, let's say, online banking), you need 
to scale your infrastructure accordingly to handle the load you're 
expecting. You can't just say that wiring new payments must have higher 
priority than say checking your account balance.

If you run a critical network infrastructure, it's your responsibility 
to estimate the expected traffic/load (e.g. via benchmarks and erlang 
calculations) and check whether the server you've put there can handle 
this. If not, you need to either put a stronger server there, or scale 
the load over more servers.

Andreas




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