[Zope] Re: CST 0.9 Problems under load?

Tim Hicks tim@sitefusion.co.uk
Mon, 18 Feb 2002 14:43:32 -0000


> > I did a quick search on the nip list archive, but couldn't find Terry
> Kerr's
> > patch.  Where can I find it?  I'd like to give the patches a try.  The
> only
> > problem is, the server probably won't see the same kind of load until
this
> > time next year.  Do you have any good ways of programmatically loading
the
> > server and invoking the session machinery?  Is this where 'ab' comes in?
>
> Terry's message to me on the subject is attached.  It doesn't sound like
the
> same problem, though. :-(

Agreed.

> There is a module named "Sessions.stresstests.stresstestMultiThread.py" in
> the Zope 2.5 sessioning stuff that tries to put the sessioning machinery
> under load.  It might be adapted for CST.
>
> If you could create the same problem with "ab", that would be just as
valid
> a test.  Anything to recreate the error condition(s).
>
> > > I'm afraid for now that I'm going to have to suggest that you either
> wait
> > > for CST 1.0 (which has not ETA as of now) or try the Zope 2.5
Sessioning
> > > machinery.

Have decided to switch to 2.5.x and see what happens.  Will also put some
time into trying to reliably reproduce the errors with ab and/or
stresstestMultiThread.py.  Will post again if anything interestings turns
up.  FWIW, I'm not sure any more that it is a load issue... I just received
more keyerror reports at a time when the server is highly unlikely to be
under strain.

> > OK, fair enough.  I realise that CST has turned into a bit of a
> side-project
> > for you now.  If I manage to reproduce the same sort of results using
the
> > 2.5.0 session machinery, will I stand a better chance of seeing a fix?
> I'd
> > love to be able to help, but I'm well over my head at the moment.
>
> If there was a replicable test case that reproduced a specific failure for
> CST 0.9, I'd almost certainly be able to fix it in a reasonable amount of
> time.  But I'm unable to take action on "it does X under nonspecific
> conditions" types of bugreports because I can't even begin to estimate how
> long it would take to guess the conditions under which the error is
raised.

Understood.  Now I've got my homework, I'll make a stab :-)

> There's an equal chance of seeing a fix for either CST or Zope 2.5 out of
me
> the moment, which is just about zero for at least the next two weeks.
> :-(  That said, I believe the sessioning stuff in Zope 2.5 is very stable.
> I want to write a compatibility layer between its API and the CST API and
> release *that* as "CST 1.0 " (for use in Zope older than 2.5) as soon as I
> can (if that's even possible).  I've realized that I cannot support both
in
> good faith and I need to find a way to merge the two codebases somehow.

That sounds interesting.

> If I find anything out, I'll send mail to the list.
>
> Sorry again!

Thanks for your time,

tim