[SR-Users] ingress timer

[Alex Balashov]

On 01/02/2014 01:39 AM, Kelvin Chua wrote:

> those timers are for INVITES sent by kamailio right? starting from
> t_relay() of the INVITE
> what i am looking for is, when i receive an INVITE, i start counting.

TM's timers - and anything else TM does - are reliant on a transaction 
existing.  A transaction is not created until t_relay() is called.

> the reason behind is, with all the functions involving several
> sql_xquery() involved to find out where to send the t_relay(),
> there will be unforeseen delays which might cause a very high PDD for my
> callers, i don't want them to wait.

Even if you had such a timer fire, your database query would still block 
the SIP worker thread that's handling the request route.

If you have database calls that could get hung for several hundred 
milliseconds, or even worse, several seconds, the solution to this 
problem is to fix your architecture and your database calls. Bluntly 
speaking, you're doing it wrong. No database calls or other external 
calls upon which Kamailio relies for call processing should be taking 
long enough to execute that PDD concerns are warranted, or that you 
should need timers to deal with them.

-- Alex

-- 
Alex Balashov - Principal
Evariste Systems LLC
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