[asterisk-bugs] [Asterisk 0013220]: [patch] Calls in high-weighted queue block low-weighted

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=13220 
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Reported By:                garychen
Assigned To:                mmichelson
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Project:                    Asterisk
Issue ID:                   13220
Category:                   Applications/app_queue
Reproducibility:            always
Severity:                   major
Priority:                   normal
Status:                     closed
Asterisk Version:           1.4.19 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
Resolution:                 fixed
Fixed in Version:           
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Date Submitted:             2008-08-01 08:28 CDT
Last Modified:              2009-03-30 11:26 CDT
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Summary:                    [patch] Calls in high-weighted queue block
low-weighted
Description: 
I have two queues, weighted 4 and 5. High priority calls are placed in
Q6002, while low priority ones in Q6001.

All agents are member of both queues.

The problem is whenever there's a high priority call ringing on an agent
(the agent not answer the call), low priority calls not routed to any idle
agents. They are blocked.
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---------------------------------------------------------------------- 
 (0102399) svnbot (reporter) - 2009-03-30 11:26
 http://bugs.digium.com/view.php?id=13220#c102399 
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Repository: asterisk
Revision: 185072

_U  trunk/
U   trunk/apps/app_queue.c

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r185072 | mmichelson | 2009-03-30 11:26:48 -0500 (Mon, 30 Mar 2009) | 45
lines

Merged revisions 185031 via svnmerge from 
https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r185031 | mmichelson | 2009-03-30 11:17:35 -0500 (Mon, 30 Mar 2009) | 39
lines
  
  Fix queue weight behavior so that calls in low-weight queues are not
inappropriately blocked.
  
  (This is copied and pasted from the review request I made for this
patch)
  
  Asterisk has some odd behavior when queue weights are used. The current
logic used when
  potentially calling a queue member is:
  
  If the member we are going to call is part of another queue and _that
other queue has any 
  callers in it_ and has a higher weight than the queue we are calling
from, then don't try 
  to contact that member. The issue here is what I have marked with
underscores. If the 
  higher-weighted queue has any callers in it at all, then the queue
member will be unreachable 
  from the lower-weighted queue. This has the potential to be really
really bad if using a 
  queue strategy, such as leastrecent or fewestcalls, with the potential
to call the same 
  member repeatedly.
  
  The fix proposed by garychen on issue 13220 is very simple and, as far
as I can see, works 
  well for this situation. With this set of changes, the logic used
becomes:
  
  If the member we are going to call is part of another queue, the other
queue has a higher 
  weight than the queue we are calling from, and the higher weight queue
has at least as many 
  callers as available members, then do not try to contact the queue
member. If the higher 
  weighted queue has fewer callers than available members, then there is
no reason to deny 
  the call to this member since the other queue can afford to spare a
member.
  
  Since the fix involved writing a generic function for determining the
number of available 
  members in the queue, I also modified the is_our_turn function to make
use of the new 
  num_available_members function to determine if it is our turn to try
calling a member. There 
  is one small behavior change. Before writing this patch, if you had
autofill disabled, then 
  if you were the head caller in a queue, you would automatically be told
that it was your 
  turn to try calling a member. This did not take into account whether
there were actually any 
  queue members available to take the call. Now we actually make sure
there is at least one 
  member available to take the call if autofill is disabled.
  
  (closes issue http://bugs.digium.com/view.php?id=13220)
  Reported by: garychen
  
  Review: http://reviewboard.digium.com/r/202/
........

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http://svn.digium.com/view/asterisk?view=rev&revision=185072 

Issue History 
Date Modified    Username       Field                    Change               
====================================================================== 
2009-03-30 11:26 svnbot         Checkin                                      
2009-03-30 11:26 svnbot         Note Added: 0102399                          
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