[Tickets #12930] AS: Endless loop with Samsung phone

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Ticket URL: http://bugs.horde.org/ticket/12930
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  Ticket             | 12930
  Created By         | Thomas Jarosch <thomas.jarosch at intra2net.com>
  Summary            | AS: Endless loop with Samsung phone
  Queue              | Synchronization
  Version            | Git master
  Type               | Bug
  State              | Unconfirmed
  Priority           | 1. Low
  Milestone          |
  Patch              |
  Owners             |
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Thomas Jarosch <thomas.jarosch at intra2net.com> (2014-01-21 14:13) wrote:

Hi,

I've one box that somehow triggers an endless loop via ActiveSync  
until the PHP timeout is reached.

The Samsung phone sends a request and the httpd process gets stuck in  
a loop, eating up 100% CPU time. I've tried to attach "strace" to it  
but it does not communicate anything with the linux kernel, so I guess  
it's stuck in a loop.

The last bits I see in the ActiveSync log look like this:

2014-01-21T11:59:45+01:00 ef6bd35e390f8ed625df47ceaee3ae1f DEBUG:  
[18254] I    <Folder>
2014-01-21T11:59:45+01:00 ef6bd35e390f8ed625df47ceaee3ae1f DEBUG:  
[18254] I     <SyncKey>
2014-01-21T11:59:45+01:00 ef6bd35e390f8ed625df47ceaee3ae1f DEBUG:  
[18254] I       {52cbc9bb-e888-4cd3-92ed-17f95c4fb70f}1
2014-01-21T11:59:45+01:00 ef6bd35e390f8ed625df47ceaee3ae1f DEBUG:  
[18254] I     </SyncKey>
2014-01-21T11:59:45+01:00 ef6bd35e390f8ed625df47ceaee3ae1f DEBUG:  
[18254] I     <FolderId>
2014-01-21T11:59:45+01:00 ef6bd35e390f8ed625df47ceaee3ae1f DEBUG:  
[18254] I       RI
2014-01-21T11:59:45+01:00 ef6bd35e390f8ed625df47ceaee3ae1f DEBUG:  
[18254] I     </FolderId>
2014-01-21T11:59:45+01:00 ef6bd35e390f8ed625df47ceaee3ae1f DEBUG:  
[18254] I     <Options>
2014-01-21T11:59:45+01:00 ef6bd35e390f8ed625df47ceaee3ae1f DEBUG:  
[18254] I      <MaxItems>

The full sync log of the device is attached to this report.

Horde_ActiveSync version is 2.8.5. Any known, related issue?

I'm currently thinking about ways to debug this since I don't have any  
hint what might be wrong.
My first uneducated guess is that something is wrong in the binary  
WBXML data and we run into an endless loop while decoding it. Just a  
*wild* theory though.

Installing xdebug will probably slow down the productive box to a crawl :(

May be "gdb" might do the trick to debug this:
http://derickrethans.nl/what-is-php-doing.html

Cheers,
Thomas




Thomas Jarosch <thomas.jarosch at intra2net.com> (2014-01-21 14:13)  
uploaded: endless_loop_log.txt

http://bugs.horde.org/h/services/download/?app=whups&actionID=download_file&file=endless_loop_log.txt&ticket=12930&fn=%2Fendless_loop_log.txt