[Zope] externalmount & zeo voodoo

Bak @ kedai kedai@kedai.com.my
Sun, 11 Mar 2001 00:20:11 +0800


>
>It sounds like you have two issues:
>
> 1.  you need better write performance.  this can be done by minimizing
>conflicterrors.
>
> 2.  your zope is apparently unstable (which may have nothing to do with
the
>number of conflict errors you're getting)
>
>Issue #1 is addressable by new application level conflict resolution code
>added to ZODB which should be out in 2.3.1b2 (the release of which is
>currently pending on new catalog code to pass all of its unit and
>performance tests).  You can read about it at
>http://www.zope.org/Members/jim/ZODB/ApplicationLevelConflictResolution.
>Other complementary ways to deal with this are intelligent coding (don't do
>writes when you don't have to, don't modify objects that you don't need
to),
>appropriate data structuring (use lots of subfolders in objectmanagers, use
>other partitioned data structures like BTrees when possible), and

can you elaborate more on using lots of subfolders and BTrees

knowing
>when to punt and use a relational database that uses locking instead of
>optimistic concurrency like the ZODB.  There's no cookie-cutter solution...
>hopefully when folks get used to the new app-level conflict resolution,
>they'll make use of it in their products to increase write performance and
>minimize conflicts.  I'm going to try this for the next sessioning release.
>The current generation of Zope products know nothing about conflict
>resolution, so it'll probably take a while for it to become mainstream.
>
>Issue #2 is separate... you should turn on request logging (see the -M

i see this happening when i enabled poll.  when there's a lot of users
clicking, zope restarts.  the restarts stop when i took out poll.

otherwise, zope has been solid like a rock

>switch in z2.py) and use the script at
>http://www.zope.org/Members/mcdonc/HowTos/DEBUG-LOG (ignore the bit at the
>top about inserting stuff into z2.py, it's been superseded by the -M
switch)
>to figure out what requests aren't returning from a method call.  With that
>info, you should hopefully be able to establish a pattern and isolate the
>problem.
i'll try and enable poll and start zope with -M

thanks
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