[ZODB-Dev] RE: [Zope] Analyzing ZODB objects

[Gfeller Martin]

I have similar needs as Bjorn, and would love to have *some* way to 
ask Python about the "biggest" in-memory objects it knows about and
about the size of any object.

I just happens that some of these objects might be objects in 
ZODB's caches, but this is intrinsically a Python issue, 
not a ZODB issue.

I agree with Dieter that memory is cheap, but there is a 32bit 
address limit with this Python running on the OS I use. 
Moreover, CPUs are fast, and nevertheless, profilers are useful.

Best regards,
Martin






Date: Mon, 27 Oct 2003 16:46:50 +0800
From: "Bjorn Stabell" <bjorn at exoweb.net>
Subject: RE: [ZODB-Dev] RE: [Zope] Analyzing ZODB objects


Toby:
> > Well, we still run out of memory, and then it's useful to 
> know why. :) 
> > Caring about memory usage is caring about (one kind of) scalability.
> 
> How would you debug this problem in an application that didnt 
> use ZODB?
> 
> Why does ZODB make a difference?

It's just all things considered, it's very complicated;

- It is, by nature, not easy to debug memory usage of Python
applications
- It is even harder to debug systems with persistent objects and classes
that evolve
- It is much harder still to debug big (and complex) systems that are
not very well documented

It would be good to have better tools (e.g., DB admin tool) and more
docs (which I guess the archived version of this thread is helping
with), especially since Zope+ZODB is a platform, not a one-off
application.

I'm aware Zope is open source and I should contribute code, not
complaints.  Apologies :)  I've used Zope/Python for a while, and I'm
not about to switch.

Bye,
-- 
Bjorn