[asterisk-bugs] [Asterisk 0012127]: Using state_interface and Local channels allows several simultenous calls to be sent to agent

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A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=12127 
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Reported By:                atis
Assigned To:                putnopvut
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Project:                    Asterisk
Issue ID:                   12127
Category:                   Applications/app_queue
Reproducibility:            sometimes
Severity:                   minor
Priority:                   normal
Status:                     assigned
Asterisk Version:           SVN 
SVN Branch (only for SVN checkouts, not tarball releases):  trunk 
SVN Revision (number only!): 103809 
Disclaimer on File?:        N/A 
Request Review:              
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Date Submitted:             03-03-2008 12:26 CST
Last Modified:              03-13-2008 17:43 CDT
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Summary:                    Using state_interface and Local channels allows
several simultenous calls to be sent to agent
Description: 
I've seen this situation on 8-CPU 3GHz Xeon, that agent gets 4 queue calls
simultaneously. 

For now i've been able to avoid this by checking/setting group at
beginning of Local channel, setting call-limit=1 for SIP peers (only for
those who shouldn't receive more than 1 call simultaneously) and checking
group upon unsuccessful Dial from Local channel. Those 3 fixes together are
giving some good results for one most-problematic queue, however that's not
a permanent and stable solution. If queue is creating several channels at
the same time, on slower but multi-cored systems this could lead to race
condition between GROUP_COUNT and Set(GROUP()) in two parallel channels,
and call-limit=1 also can't always be set.

I'm not sure if this can be implemented in good way, but I think the most
appropriate solution for this would be that Queue is setting device state
of Local channel, and other queue(s) (if member is in multiple queues)
receives event from first queue's devicestate change.

My system is Asterisk 1.4.14 with backported state_interface from r103809
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---------------------------------------------------------------------- 
 putnopvut - 03-13-08 17:43  
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I talked with atis on IRC some, and he alerted me that while the latest
patch was working, it was not exactly complete and he suggested a new
method for updating the status of members. 12127v3.patch has the following
differences from v2.

1. On failure to request a channel, instead of updating the member's
status, make sure to update the status of that member in all queues to
which that member belongs.

2. Call a single common function for whenever member status changes. This
unifies   some repeated code and will hopefully reduce errors that may
occur in the future due to code changes.

If you could please test to make sure there aren't any errors in the
latest patch, that would be great. Thanks! 

Issue History 
Date Modified   Username       Field                    Change               
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03-13-08 17:43  putnopvut      Note Added: 0083931                          
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