[ZODB-Dev] Timeout in UndoSearch

[Dieter Maurer]

Toby Dickenson wrote at 2004-1-15 16:57 +0000:
>> >> I propose this is added to the standard zope distribution, the timeout
>> >> should probably be set in an environment variable or something, it would
>> >> also be nice if as you click "earlier transactions" the timeout would
>> >> increase, but that may be more work than it's worth.
>
>>> Someone else suggested to limit the search by transaction
>>> commit time (rather than searching runtime).
>>> E.g. give me all "Undo" possibility within the last day/week/month.
>
>I think these are two distinct requirements. The first is a safety limit that 
>stops your storage spinning for longer than is healthy, and is set by the 
>storage admin. The second is a different type of filter, set by the 
>application developer.

I hate functionality without clear semantics:

  The proposed patch simply returns n undo records

    *  without indication that it has hit the timeout

    *  without a way to adjust the timeout (without restarting
       and reconfiguring Zope)

   Reading the undoLog does not need a lock (although it must prevent
   packing to finish). Thus, other operations can (in principle -- not
   sure whether ZEO can handle this) be interlaced with the operation.

   Currently, I do not see the need for a realtime based
   semantically unclear timeout.
   If the above problems are addressed, I might be happier...
   

-- 
Dieter