[SR-Users] Seeing Large Waits

[Daniel-Constantin Mierla]

Hello,

do not forget about the core parameters related to latency, they can be
useful to detect slow actions or db queries:

  - https://www.kamailio.org/wiki/cookbooks/devel/core#latency_cfg_log

Cheers,
Daniel


On 03.05.18 06:49, Alex Balashov wrote:
> Hi Mack,
>
> Happy to help!
>
> There must be a hidden source of I/O wait somewhere. It may not be
> database calls, but there's something. This shouldn't be happening in a
> mostly static config. 
>
> Can you share the numbers from your load testing? At what point did you
> start seeing retransmissions, if any? What kind of delays are you
> seeing?
>
> -- Alex
>
> On Thu, May 03, 2018 at 12:48:38AM -0400, Mack Hendricks wrote:
>
>> Hey Alex,
>>
>> Thanks for the insight. I remember reading your article before and it was super helpful. I think we disabled all of the heavy database operations, but I will double check.
>>
>> We are building the RURI using the cfg_rpc module, so we aren’t hitting a database.   We have a failure route that causes another RURI to be created, which sends the call to a Freeswitch server to play a message.
>>
>> Let me know if you see any issue with this, I will double check the database calls to be safe.
>>
>> Sent from my iPhone
>>
>>> On May 2, 2018, at 11:36 PM, Alex Balashov <abalashov at evaristesys.com> wrote:
>>>
>>> Hi Mack,
>>>
>>> What sort of end-to-end delays are you seeing, from receipt of request
>>> until immediately before t_relay()?
>>>
>>> You can profile this with the benchmark module:
>>>
>>>   https://kamailio.org/docs/modules/5.1.x/modules/benchmark.html
>>>
>>> Or my preferred method, the hard way:
>>>
>>>        # At the practical start of request processing.
>>>
>>>        $avp(proc_start) = $TV(Sn);
>>>
>>>        # At the end, right before calling t_relay() or forward().
>>>
>>>        $var(cur_time) = $TV(Sn);
>>>
>>>        $var(proc_diff) = (
>>>                (((
>>>                  $(var(cur_time){s.select,0,.}{s.int}) -
>>>                  $(avp(proc_start){s.select,0,.}{s.int})
>>>                ) * 1000000)
>>>                +
>>>                (
>>>                 $(var(cur_time){s.select,1,.}{s.int}) -
>>>                 $(avp(proc_start){s.select,1,.}{s.int})
>>>                ) / 1000) mod 1000
>>>        );
>>>
>>>        xlog("L_INFO", "[R-MAIN:$ci] -> Request processing delay: $var(proc_diff) ms\n"););
>>>
>>> Also, for general background on this topic, you might consider my
>>> article on the subject of Kamailio performance characteristics:
>>>
>>>   http://blog.csrpswitch.com/tuning-kamailio-for-high-throughput-and-performance/
>>>
>>> If I had to guess, shooting from the hip, you've got some really slow
>>> database queries somewhere.
>>>
>>> -- Alex
>>>
>>>> On Wed, May 02, 2018 at 06:19:00PM -0400, Mack Hendricks wrote:
>>>>
>>>> Hey All,
>>>>
>>>> We are load testing Kamailio 4.2.3 and we are seeing the waiting within the transaction manager increasing.   I’ve increased the children from 8 to 16 to 24, but we are still seeing a large amount of waiting.  I don’t see an errors in the logs.   Can anyone give me a clue on where to look. 
>>>>
>>>> 05-02-18_03:07:38 PM
>>>> tm.stats
>>>> {
>>>>        current: 390
>>>>        waiting: 226
>>>>        total: 2361
>>>>        total_local: 0
>>>>        replied_locally: 1406
>>>>        6xx: 0
>>>>        5xx: 0
>>>>        4xx: 88
>>>>        3xx: 0
>>>>        2xx: 3180
>>>>        created: 2361
>>>>        freed: 1971
>>>>        delayed_free: 0
>>>> }
>>>>
>>>> Mack Hendricks / Head of Support / dOpenSource
>>>> web: http://dopensource.com <http://dopensource.com/>
>>>> support: +888-907-2085
>>>> dSIPRouter <http://dsiprouter.org/> - GUI focused on implementing Kamailio to provide SIP Trunking and PBX Hosting Services
>>>>
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>>>> Kamailio (SER) - Users Mailing List
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>>>
>>> -- 
>>> Alex Balashov | Principal | Evariste Systems LLC
>>>
>>> Tel: +1-706-510-6800 / +1-800-250-5920 (toll-free) 
>>> Web: http://www.evaristesys.com/, http://www.csrpswitch.com/

-- 
Daniel-Constantin Mierla
www.twitter.com/miconda -- www.linkedin.com/in/miconda
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