[Users] Re: [Devel] "detached" timer

[Bogdan-Andrei Iancu]

Hi TR,

that explains it! if acc becomes blocking the transactions will be 
delayed for certain ops (as TM will block processing in the callbacks 
triggered by acc), so the probability for the race to show up was 
increased.

So the "detached timer" was not the source of the problem - as I told 
you, it can never lead to block or crash -, but it was a side effect 
because of the acc blocking.

regards,
bogdan

T.R. Missner wrote:
> FYI All
>
> This turned out to be a database write ( acc ) that was blocking due 
> to a raid card problem.
>
>
>
> T.R. Missner wrote:
>> Is it possible the locked state I am seeing with openser leads to the 
>> "detached" timer?
>> Since the "detached" timer is a race, it would make sense to see the 
>> race condition after openser locks up and messages buffer up in the 
>> stack.
>> When a bunch of messages are processed all at once by multiple 
>> threads the race condition would occur.
>> Does this make sense?
>>
>> Maybe I have been focusing on the wrong place.
>>
>> Ignoring the "detached" timer what could cause openser to hang for a 
>> couple seconds then clear every 5 - 10 minutes?
>>
>> Ideas?
>>
>> We are seeing this on 3 different productions servers.
>>
>> Thanks
>>
>> TR
>>
>> using openser1.1.1
>>
>>
>>
>> T.R. Missner wrote:
>>> Bogdan,
>>>
>>> I have been chasing this for days and done lots of debugging.
>>> using 1.1.1
>>> While looking at the network trace at the time of these messages ( I 
>>> usually see at least 5 in a row with differing hex values ) I see 
>>> many incoming packets coming into the box and no response from the 
>>> proxy for somewhere between 5 - 10 seconds, then a flood a responses 
>>> from the proxy.
>>> I can email you a sample pcap file if you like.
>>> As part of my debugging I forced a 100 reply at the very top of my 
>>> cfg file.
>>> The forced 100 was not sent during the locked up time leading me to 
>>> believe openser was not processing incoming packets.
>>> I have now seen this on multiple servers in different locations. 
>>> Likely a particular customer call flow is causing this but I have 
>>> not been able to pin it down to the exact customer. These proxies 
>>> run pretty fast during the day so finding a pattern leading up the 
>>> this issue is difficult. What could I add to the Log output to 
>>> identify the offending sip-callid? Is sip-callid or branch tag or 
>>> anything similar easily accessible in any of the data structs in 
>>> timer.c?
>>>
>>> TR
>>>
>>> Bogdan-Andrei Iancu wrote:
>>>> Hi TR,
>>>>
>>>> it is race between expire even (from timer) and inserting again on 
>>>> a timer list.
>>>>    1 is the final response timer list (fr_timer)
>>>>    3 id the wait timer list (wt_timer)
>>>>
>>>> I would say there is no way this could leas to a any kind of lock.
>>>>
>>>> what version are you using? what makes you say it locks?
>>>>
>>>> regards,
>>>> bogdan
>>>>
>>>> T.R. Missner wrote:
>>>>> Does anyone know what causes this?
>>>>>
>>>>> */set_timer for 1 list called on a "detached" timer -- ignoring /*
>>>>>
>>>>> I also see
>>>>>
>>>>> */set_timer for 3 list called on a "detached" timer -- ignoring /*
>>>>>
>>>>>
>>>>>
>>>>> When this happens Openser seems to lock up for 10 seconds or so.
>>>>>
>>>>> >From searching it appears this is caused by a race but I am not 
>>>>> sure what the race is or why this results in an unresponsive 
>>>>> openser instance for multiple seconds.
>>>>>
>>>>> Transaction expiration racing reply?
>>>>>
>>>>>
>>>>> Desperately need to understand how this could be triggered so I 
>>>>> can get customer to adjust system.
>>>>>
>>>>> Any way to adjust?
>>>>>
>>>>> tried tweaking fr_inv_timer but no joy.
>>>>>
>>>>>
>>>>>
>>>>> TR