[Zope-dev] session concurrency

[Santi Camps]

> It is unlikely that the the low conflict connection causes your
> problem. "Low conflict" affects the following situation:
> 
>    You try to load an object (because it is not in your ZODB cache)
>    and get informed that is has been modified (by another commited
>    transaction) since your transaction started.
> 
>    With a normal ZODB connection, you will get a "ReadConflictError"
>    as adding the object to your ZODB cache would make it inconsistent:
>    some objects would have the state from your transactions start
>    and others from a later date.
>    With a low conflict connection, the inconsistency is accepted
>    and no "ReadConflictError" is raised.
> 
> As you described, you loose the session object.
> This is not easily understood as the effect of a cache inconsistency.
> 

Sure.  Disabling Low conflict hasn't solved anything. 

I'm not able to find where is the problem.  I have not enought knowledge
of Zope internals.  I will try to store my data in persisten subobjects,
as you said.

One thing is true:  Changing session object simultaniously in various
frames doesn't work fine.  Sometimes session data is not the espected
becouse another frame has erased your changes in the session object.  

I think this is a serious inconvenient in front of other platforms. 
>From my point of view, it would be better to have SESSION out of the
transaction but with changes stored inmediatly.  You don't?

Perhaps some day I will be able to implement this for myself.  Until
that, do you think I should enter a bug, or this cann't be considered as
a bug?

Thanks for your help

Santi Camps