[Zope-dev] Cache growing during single REQUEST

Dieter Maurer dieter at handshake.de
Sun Sep 14 17:33:14 EDT 2003


Tim Peters wrote at 2003-9-14 16:40 -0400:
 > ...
 > [Dieter Maurer]
 > > Whoever wants to use it right now: the "no more ReadConflictErrors"
 > > patch on
 > >
 > >   <http://www.dieter.handshake.de/pyprojects/zope>
 > >
 > > does precisely this (for storages that support history information).
 > 
 > How has that been working out for people (not limited to Dieter)? 

It works fine for us.

We are working on a content management system with tens of thousands of
large SGML/XML documents. My colleague likes to make parallel
imports. Before the patch, cataloguing (using an improved
version of Shane's "QueueCatalog") did almost not proceed
due to an incredible amount of "ReadConflictError"s.
After the patch, there are occasional "WriteConflictError"s
(caused by the catalog BTrees performing conflict resolution only
at the leaf level), but in general the system is stable.

We now use it also in production systems without problems.

 > That's
 > indeed what we're after, although Jeremy has in mind deeper/broader changes
 > aimed at being more efficient than digging thru history.

The history is consulted only rarely (only when the current state
is too young). However, in this case, the pickled data is read
twice. Of course, I do not mind when it gets more efficient...


Dieter



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