[SR-Users] crash at 480 reply to INVITE

Daniel-Constantin Mierla miconda at gmail.com
Tue Feb 5 22:33:58 CET 2019


It is rather strange that it got like "frozen" for 15 minutes. Was there
a high CPU during that interval?

Typically, if there is a deadlock that block processing, then it does
not recover until restart. But in this case is no restart, because that
destroys active trasactions and no CANCEL would have been issued.

Is the system a virtual machine, container or bare metal?

I encountered in the past that some VMs got fronzen due to VM manager
doing some backup or similar activities ...

Cheers,
Daniel

On 05.02.19 21:33, Juha Heinanen wrote:
> Daniel-Constantin Mierla writes:
>
>> I'll look into it. Was there a possibility that some operation could
>> have taken very long, for example writing accounting database record?
> Thanks.  I don't think that this is db related issue.  Here is a
> summary:
>
> - K receives INVITE at 17:43:28 and forwards it over udp to uas
> - uas immediately responds with 183 followed by 180, which k forwards to UAC
> - at 17:44:29 uas responds again with 180 and K forwards it to UAC
> - at 17:44:44 K's invite timeout timer fires and it sends "408 request
>   timeout" to uac, which responds with ack
> - at that point K should also have send CANCEL to uas, but it didn't
> - after that k goes to deep sleep, i.e., it does not react to any
>   new incoming requests from anybody nor to several "480 request
>   terminated" replies from the uas
> - about 15 minutes later at 18:00:23, K wakes up and sends two cancel
>   requests to uas
> - uas replies to cancels with "481 transaction does not exist"
> - then K sends several ACKs to the uas and crashes
>
> So it seems that crash is side effect of K not sending cancel to the uas
> immediate.  Instead it goes to sleep and doesn't feel well after waking
> up 15 minutes later.
>
> The real questions are why didn't K send the CANCEL immediately and went
> to sleep instead.  How to find out why it happened?
>
> -- Juha

-- 
Daniel-Constantin Mierla -- www.asipto.com
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