[storm] Performance Problems using List and Pickle properties

[Jamu Kakar]

Hi Jürgen,

On Fri, Oct 2, 2009 at 11:56 AM, Jürgen Kartnaller
<kartnaller at lovelysystems.com> wrote:
> After a long time having problems with performance going down in our
> Zope/Storm applications I could now figure out where it is coming from. In
> my latest app using tornado and Storm I have the same problem.
>
> When using List or Pickle properties (both are derived from
> MutableValueVariable) I found that any time a property is read a flush event
> hook is added but never removed. The longer the app runs the more hooks are
> registered which result in low perfomance in store.flush.
> The flush event hook is unhooked on the 'stop-tracking-changes' event which
> is only emited if an object is removed from the database.

Are you using the latest version of Storm?  I remember a problem
like this being fixed some time ago.  I think this is the fix for
the problem I'm thinking of:

revno: 275 [merge]
committer: Thomas Hervé <thomas at canonical.com>
branch nick: trunk
timestamp: Mon 2008-11-03 20:38:06 +0100
message:
  Merge variable-referenceset-leak [r=niemeyer,jkakar]

  Change the way MutableValueVariable hooks up to the store event system, by
  overriding get and set. This works around a leak discovered when using
  PickleVariable in a ReferenceSet.

Thanks,
J.