[asterisk-bugs] [Asterisk 0010248]: chan_iax2 VNAK storm seen

noreply at bugs.digium.com noreply at bugs.digium.com
Wed Aug 1 16:59:03 CDT 2007


The following issue has been ASSIGNED. 
====================================================================== 
http://bugs.digium.com/view.php?id=10248 
====================================================================== 
Reported By:                stevedavies
Assigned To:                russell
====================================================================== 
Project:                    Asterisk
Issue ID:                   10248
Category:                   Channels/chan_iax2
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     assigned
Asterisk Version:           1.4.5 
SVN Branch (only for SVN checkouts, not tarball releases): N/A  
SVN Revision (number only!):  
Disclaimer on File?:        N/A 
Request Review:              
====================================================================== 
Date Submitted:             07-20-2007 04:47 CDT
Last Modified:              08-01-2007 16:58 CDT
====================================================================== 
Summary:                    chan_iax2 VNAK storm seen
Description: 
Saw this happening on a customer between two boxes:

Tx-Frame Retry[-01] -- OSeqno: 064 ISeqno: 060 Type: IAX     Subclass:
LAGRP  
   Timestamp: 200069ms  SCall: 00061  DCall: 00059 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 011 ISeqno: 011 Type: IAX     Subclass:
VNAK   
   Timestamp: 29274ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
Tx-Frame Retry[-01] -- OSeqno: 064 ISeqno: 060 Type: IAX     Subclass:
LAGRP  
   Timestamp: 200069ms  SCall: 00061  DCall: 00059 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 011 ISeqno: 011 Type: IAX     Subclass:
VNAK   
   Timestamp: 29285ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
Tx-Frame Retry[-01] -- OSeqno: 064 ISeqno: 060 Type: IAX     Subclass:
LAGRP  
   Timestamp: 200069ms  SCall: 00061  DCall: 00059 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 011 ISeqno: 011 Type: IAX     Subclass:
VNAK   
   Timestamp: 29294ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
Tx-Frame Retry[-01] -- OSeqno: 064 ISeqno: 060 Type: IAX     Subclass:
LAGRP  
   Timestamp: 200069ms  SCall: 00061  DCall: 00059 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 011 ISeqno: 011 Type: IAX     Subclass:
VNAK   
   Timestamp: 29305ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
Tx-Frame Retry[-01] -- OSeqno: 064 ISeqno: 060 Type: IAX     Subclass:
LAGRP  
   Timestamp: 200069ms  SCall: 00061  DCall: 00059 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 011 ISeqno: 011 Type: IAX     Subclass:
VNAK   
   Timestamp: 29314ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
Tx-Frame Retry[-01] -- OSeqno: 064 ISeqno: 060 Type: IAX     Subclass:
LAGRP  
   Timestamp: 200069ms  SCall: 00061  DCall: 00059 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 011 ISeqno: 011 Type: IAX     Subclass:
VNAK   
   Timestamp: 29341ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
Tx-Frame Retry[-01] -- OSeqno: 064 ISeqno: 060 Type: IAX     Subclass:
LAGRP  
   Timestamp: 200069ms  SCall: 00061  DCall: 00059 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 011 ISeqno: 011 Type: IAX     Subclass:
VNAK   
   Timestamp: 29351ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
Tx-Frame Retry[-01] -- OSeqno: 064 ISeqno: 060 Type: IAX     Subclass:
LAGRP  
   Timestamp: 200069ms  SCall: 00061  DCall: 00059 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 011 ISeqno: 011 Type: IAX     Subclass:
VNAK   
   Timestamp: 29360ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
Tx-Frame Retry[-01] -- OSeqno: 064 ISeqno: 060 Type: IAX     Subclass:
LAGRP  
   Timestamp: 200069ms  SCall: 00061  DCall: 00059 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 011 ISeqno: 011 Type: IAX     Subclass:
VNAK   
   Timestamp: 29369ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
Tx-Frame Retry[-01] -- OSeqno: 064 ISeqno: 060 Type: IAX     Subclass:
LAGRP  
   Timestamp: 200069ms  SCall: 00061  DCall: 00059 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 011 ISeqno: 011 Type: IAX     Subclass:
VNAK   
   Timestamp: 29378ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
Tx-Frame Retry[-01] -- OSeqno: 064 ISeqno: 060 Type: IAX     Subclass:
LAGRP  
   Timestamp: 200069ms  SCall: 00061  DCall: 00059 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 011 ISeqno: 011 Type: IAX     Subclass:
VNAK   
   Timestamp: 29387ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
etc etc etc etc

It did stop eventually when:

Rx-Frame Retry[ No] -- OSeqno: 010 ISeqno: 014 Type: IAX     Subclass:
HANGUP 
   Timestamp: 30238ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
   CAUSE CODE      : 0

Tx-Frame Retry[-01] -- OSeqno: 014 ISeqno: 011 Type: IAX     Subclass: ACK
   
   Timestamp: 30238ms  SCall: 00061  DCall: 00047 [196.40.106.94:4569]
Rx-Frame Retry[ No] -- OSeqno: 014 ISeqno: 014 Type: IAX     Subclass:
VNAK   
   Timestamp: 30245ms  SCall: 00047  DCall: 00061 [196.40.106.94:4569]
Tx-Frame Retry[ No] -- OSeqno: 000 ISeqno: 000 Type: IAX     Subclass:
INVAL  
   Timestamp: 00000ms  SCall: 00061  DCall: 00047 [196.40.106.94:4569]
====================================================================== 

---------------------------------------------------------------------- 
 svnbot - 08-01-07 16:58  
---------------------------------------------------------------------- 
Repository: asterisk
Revision: 77887

------------------------------------------------------------------------
r77887 | russell | 2007-08-01 16:58:53 -0500 (Wed, 01 Aug 2007) | 23 lines

Fix some race conditions which have been causing weird problems in
chan_iax2.
The most notable problem is that people have been seeing storms of VNAK
frames
being sent due to really old frames mysteriously being in the
retransmission
queue and never getting removed.

It was possible that a dynamic thread got created, but did not acquire its
lock
before the thread that created it signals it to perform an action.  When
this
happens, the thread will sleep until it hits a timeout, and then get
destroyed.
So, the action never gets performed and in some cases, means a frame
doesn't
get transmitted and never gets freed since the scheduler never gets a
chance
to reschedule transmission.

Another less severe race condition is in the handling of a timeout for a
dynamic
thread.  It was possible for it to be acquired to perform at action at the
same
time that it hit a timeout.  When this occurs, whatever action it was
acquired
for would never get performed.

(patch contributed by Mihai and SteveK)
(closes issue http://bugs.digium.com/view.php?id=10289)
(closes issue http://bugs.digium.com/view.php?id=10248)
(closes issue http://bugs.digium.com/view.php?id=10232)
(possibly related to issue http://bugs.digium.com/view.php?id=10359)

------------------------------------------------------------------------ 

Issue History 
Date Modified   Username       Field                    Change               
====================================================================== 
08-01-07 16:58  svnbot         Checkin                                      
08-01-07 16:58  svnbot         Note Added: 0068255                          
08-01-07 16:58  svnbot         Status                   feedback => assigned
08-01-07 16:58  svnbot         Assigned To               => russell         
======================================================================




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