[Zope] Session manager without pickle?

[Chris McDonough]

> Unfortunately the session manager tries to pickle the connection object,
> which of course doesn't work here.
> Is it possible to avoid this?

It'll probably be a requirement in this case to either:

- create a "transient object container" that doesn't use the ZODB (which 
is ultimately doing the pickling that is causing you problems) to store 
data.

.. or ..

- to "hack around" the problem by registering a connection with a global 
connection registry for each session and storing a (string) reference to 
it in the session (instead of storing the connection object itself).

> Anyway, as session data should be stored in RAM, I don't see the point of
> pickling...

That would make life simple, but it's not always true.  People want 
persistent sessions as well as the ability to share session data across 
ZEO clients, and the current transient data container implementation 
lets that happen by using the ZODB to store session data.  The fact that 
the OOTB sessioning implementation in Zope uses ZODB to store session 
data is what is causing you problems here.

> If it's possible to do what I want, is it also possible/necessary to avoid
> multiple concurrent accesses from the same user/session?

Not really.  Frames are a problem. Spidering tools or benchmarking tools 
like "ab" might cause simultaneous writes to the same session. Even 
clicking really really fast might cause simultaneous writes to the same 
session object.  I'd give it a roll, though.  I think that the worst 
that can happen to you is that you open and close your database 
connections more often than you'd really like to.

BTW, are you aware that the relational database support in Zope does its 
own "connection pooling" and that schemes like this that are commonly 
used in Java for this kind of thing aren't really necessary?

- C


-- 
Chris McDonough                    Zope Corporation
http://www.zope.org             http://www.zope.com
"Killing hundreds of birds with thousands of stones"