[Tickets #13231] Re: Hashtable session handler doesn't unlock on session close

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Ticket URL: http://bugs.horde.org/ticket/13231
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  Ticket             | 13231
  Updated By         | arjen+horde at de-korte.org
  Summary            | Hashtable session handler doesn't unlock on session
                     | close
  Queue              | Horde Framework Packages
  Version            | Git master
  Type               | Bug
  State              | Feedback
  Priority           | 1. Low
  Milestone          |
  Patch              |
  Owners             |
+New Attachment     | Horde_Memcache.patch
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arjen+horde at de-korte.org (2014-05-29 10:01) wrote:

> Lowering the poll delay is not a viable option.  At 10 polls/second  
> (per request), that is already quite a bit of network/protocol  
> overhead.
>
> Maybe it would be better to implement a logarithmically increasing  
> delay mechanism.  Or for true performance, a hybrid flock/memcache  
> system.

After session_start(), it seems to take a few milliseconds before the  
lock on the session data is released. I noticed that frequently it  
takes a while before the first six listEvents that are started manage  
to start a session. This is due to the fact that the poll delay for  
all of them is identical, so if they are started at the same time, the  
subsequent polls to retry to get a lock on the session data will also  
coincide. In that case, it may take up to six times 100 ms before all  
processes get going. Adding some randomness in the polling would help  
to minimize that, by retrying at different intervals (see attached  
patch).



arjen+horde at de-korte.org (2014-05-29 10:01) uploaded: Horde_Memcache.patch

http://bugs.horde.org/h/services/download/?app=whups&actionID=download_file&file=Horde_Memcache.patch&ticket=13231&fn=%2FHorde_Memcache.patch