[Zope-dev] ZopePublication Competing writes/reads

[Carsten Senger]

Hermann Himmelbauer schrieb:
> Yes, I can reproduce this any time. But I looked into it further, and it's 
> quite weird:
> 
> - If I access the site without having logged in (= a new cookie/session is 
> created), it does not happen.
> - If I login, pressing F5 rapidly triggers these warnings.
> - BUT: If I logout and press F5, the warnings are still there.
> - If I close the browser/reopen it (-> New session), the warning is gone.
> 
> So it seems, once the session stores/has stored login information, this object 
> leads to a conflict. Interesting - but I still don't know what this object 
> is.

You should inspect what happens in zope.session to find out what happens 
there. From your description and the purpose of sessions probably this 
happens:

Everytime you access you site the session is checked for authentication 
informations. Sessions have a set timeout. zope.session has to write a 
new timestamp into the session so it can drop the session after the 
timeout. This can cause conflicts.
When you log out the authentication informations are removed from the 
session, but the cookie an the server side session are still there. The 
timestamp is updated with every request.
If you close your browser the cookie is removed by the browser. Until 
you authenticate zope does not create a new session/set a new cookie.

I'm quite sure that you can't get conflicts with zope.session if you use 
two different sessions at the same time and conflicts with one session 
are rare enough and with zope's conflict resolution no problem (unless 
you press F5 really fast)

..Carsten