[asterisk-dev] Suspected deadlocks in Asterisk 1.8 under heavy load

[Paul Belanger]

On 11-08-16 10:32 PM, Kevin P. Fleming wrote:
> On 08/16/2011 09:27 PM, Alistair Cunningham wrote:
>> On 17/08/11 12:23, Kevin P. Fleming wrote:
>>> Matt Nicholson committed a change to the 1.8, 10 and trunk branches
>>> today to solve a significant performance issue caused by the change to
>>> chan_sip to return the SIP hangup cause to the 'master' channel. His
>>> change made that behavior optional, even though it was already released
>>> in 1.8, because of the performance impact it has. We had another
>>> customer report a similar set of symptoms.
>>>
>>> If possible, it would be most helpful if you could try that patch on one
>>> of your affected systems before you downgrade it. I can understand if
>>> your customer is not willing to let you try that, though :-)
>>
>> Kevin,
>>
>> Thank you for this. When you say "optional", are any configuration
>> settings needed to disable it?
>
> Yes, in Asterisk 1.8 you'll need to set 'storesipcause' to 'off', since
> the default is 'on' to preserve the existing behavior. In Asterisk 10
> and later, the default will be 'off'.
>
> If we have real-world testing that shows that changing the default to
> 'off' will resolve issues such as yours, we'll consider even changing
> the default to 'off' for the Asterisk 1.8.6 release. It'd be an unusual
> step to take, but unless there is sufficient community demand for this
> feature to be enabled by default, the performance problems it causes are
> not acceptable for users who don't care about the feature.
>
I believe this is something we should look at doing, even thought it 
might be against policy.  But like you said, this requires people to 
test 1.8.6.0-rc2 (assuming we merge the patch into it). Another option 
we discussed on #asterisk-dev is to override the settings in the samples 
configs, so new installations benefit from the performance change.

Ideally, sites still using 1.4/1.6.* with large volumes of calls would 
be the best testers to confirm the performance impact of enabling and 
disabling 'storesipcause' setting.

-- 
Paul Belanger
Digium, Inc. | Software Developer
twitter: pabelanger | IRC: pabelanger (Freenode)
Check us out at: http://digium.com & http://asterisk.org