[Zope] Zope Scaling (and Groups of Users)

[Eric Seidel]

To all-

Two questions:

1.  Zope/ZEO Scaling.  I spent several hours over the past 3 days 
reading about Zope scalability with ZEO.  I am now looking for numbers.  
Two questions (nearly one and the same) which I did not find answered:

a.  How well does ZEO scale in DATA SIZE (not availability).  i.e. How 
many items can I have in a folder?  How many users/objects can it handle?
b.  Numbers.  There were no specific configuration numbers which I 
found.  How many objects?  How many users?  How much data?

I'm looking to be able to handle at least 40,000 user objects and a 
similar number of other larger data objects of various sizes (2k - 
20k+).  Users could be pushed off to an ldap server or some other 
environment via the LoginManager Mod etc, however I would still have 
40,000 user folders in a single folder.  Much of my application is of 
course generate once, serve a million times, but almost all objects can 
expect regular changes.  Currently I have implemented the bulk of my 
objects in an SQL database which I am serving through a Zope front 
end.   A pure Zope object setup however offers some conveniences over my 
setup in terms of possibly simpler access controls and, if ZEO lives up 
to it's claim, simpler scalability.  I would be interested in hearing 
users comments towards ZEOs ability to scale Zope and any specific 
numbers from various Zope/ZEO setups.  Numbers from single Zope Installs 
are also very welcome.

2.  Groups.  I have also written my own Authentication system built off 
of an SQL database to accommodate for groups, and group based access 
controls.  I have read the documentation on Zope3's plan for Groups of 
principles, however seeing as Zope3 has not even released a build yet I 
believe I will need to roll my own in this area.  I have done some 
google searching but not found any other Zope modules to handle group 
based authentication.  If anyone knows of such a module I would be very 
interested in knowing more.

Thank you all for your time.

Sincerely,
Eric Seidel