[Zope-dev] Sessions and long requests = conflicts? Mcdutils?

[Dieter Maurer]

Maciej Wisniowski wrote at 2007-4-11 20:28 +0200:
>Currently I have some problems with our application (Zope2.8.4)
>and with Conflict Errors in sessions.
>In general if we have few concurrent requests that are running
>sometimes for 3-4 minutes (and they're touching session inside)
>I get a lot of conflict errors with Inceraser, OOBTree, Length2 etc.

Session conflict errors are very common -- for the following reason:

  While individual sessions are usually used only by a single
  request at a time, they share common administrative data
  structures (e.g. the OOBTree that holds the session objects).

  The administrative data structures usually have conflict
  resolution *BUT* conflict resolution requires sufficient
  history -- and the temporary storage usually holding the sessions
  only has minimal history. Therefore, conflict resolution is
  usually ineffective (impossible) and you get lots of conflicts.



-- 
Dieter