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<b>From</b>: "Paul Belanger" <pabelanger@digium.com><br />
<b>Sent</b>: Wednesday, August 17, 2011 10:22 AM<br />
<b>To</b>: asterisk-dev@lists.digium.com<br />
<b>Subject</b>: Re: [asterisk-dev] Suspected deadlocks in Asterisk 1.8 under heavy load</span><br />
<br />
On 11-08-16 10:32 PM, Kevin P. Fleming wrote:<br />
> On 08/16/2011 09:27 PM, Alistair Cunningham wrote:<br />
>> On 17/08/11 12:23, Kevin P. Fleming wrote:<br />
>>> Matt Nicholson committed a change to the 1.8, 10 and trunk branches<br />
>>> today to solve a significant performance issue caused by the change to<br />
>>> chan_sip to return the SIP hangup cause to the 'master' channel. His<br />
>>> change made that behavior optional, even though it was already released<br />
>>> in 1.8, because of the performance impact it has. We had another<br />
>>> customer report a similar set of symptoms.<br />
>>><br />
>>> If possible, it would be most helpful if you could try that patch on one<br />
>>> of your affected systems before you downgrade it. I can understand if<br />
>>> your customer is not willing to let you try that, though :-)<br />
>><br />
>> Kevin,<br />
>><br />
>> Thank you for this. When you say "optional", are any configuration<br />
>> settings needed to disable it?<br />
><br />
> Yes, in Asterisk 1.8 you'll need to set 'storesipcause' to 'off', since<br />
> the default is 'on' to preserve the existing behavior. In Asterisk 10<br />
> and later, the default will be 'off'.<br />
><br />
> If we have real-world testing that shows that changing the default to<br />
> 'off' will resolve issues such as yours, we'll consider even changing<br />
> the default to 'off' for the Asterisk 1.8.6 release. It'd be an unusual<br />
> step to take, but unless there is sufficient community demand for this<br />
> feature to be enabled by default, the performance problems it causes are<br />
> not acceptable for users who don't care about the feature.<br />
><br />
I believe this is something we should look at doing, even thought it <br />
might be against policy. But like you said, this requires people to <br />
test 1.8.6.0-rc2 (assuming we merge the patch into it). Another option <br />
we discussed on #asterisk-dev is to override the settings in the samples <br />
configs, so new installations benefit from the performance change.<br />
<br />
Ideally, sites still using 1.4/1.6.* with large volumes of calls would <br />
be the best testers to confirm the performance impact of enabling and <br />
disabling 'storesipcause' setting.<br />
_________________<br />
<br />
What is really lost by setting 'storesipcause' to off? As I understand it it does not effect global variables? What was the usage case for the feature in 1.8? How would this effect things long term?<br />
<br />
Thanks<br />
Bryant<br /></span>