There is a bug in the RAM-based session data container implementation
that causes this under load. I've fixed it in a sandbox here (more or
less), but I've not had time to package it up nicely... I am so far
overdue in doing this that I'm not even going to say it'll be RSN.
In the meantime, please use an external data container.
Many apologies,
- C
Ron Bickers wrote:
> I'm running into what appears to be the same problem brought up by others
> several months ago regarding "random" disappearing of session variables
> under CoreSessionTracking. After combing through the archives, there didn't
> appear to be any definitive answer for the problems.
>
> I *think* my setup is fairly basic, but I can't figure out how to
> consistently reproduce the problem. In fact, *I* haven't been able to make
> it happen at all, but every 1-2 out of 10 orders ends up with an empty cart,
> and the customer clearly remembers their cart was not empty.
>
> I'm not using ZEO or anything fancy, just the RAM-based storage and cookies.
> I have the following setup for adding, updating, and viewing the cart:
>
> Python Script 'add':
>
> 'item' is a dictionary that is populated with simple numbers and strings.
> 'cart' is an array of 'items' and is stored like this:
>
> session = context.SDM.getSessionData()
> cart = session.get('cart', [])
> cart.append(item)
> session.set('cart', cart)
>
> Python Script 'update':
>
> A form passes in 'remove' as the cart index of the item to be removed:
>
> session = context.SDM.getSessionData()
> cart = session.get('cart', [])
> remove = REQUEST.form.get('remove', None)
> if remove is not None:
> del cart[remove]
> session.set('cart', cart)
>
> To place the items in a mail message for sending the order, I use the
> following simple Python Script and loop over it with dtml-in:
>
> session = context.SDM.getSessionData()
> return session.get('cart', [])
>
> This seems so simple, but seemingly randomly the above script returns []
> instead of what is in the cart. There is another session variable (a
> dictionary 'custinfo') that is populated towards the end of the user's
> ordering process that has so far not been empty on any orders.
>
> I wish I could provide more, but I don't know what else to try. Maybe
> someone can see a flaw in the way I'm storing the cart that might cause CST
> to freak...like some persistence triggering problem or something like that.
>
> _______________________
>
> Ron Bickers
> Logic Etc, Inc.
>
>
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--
Chris McDonough Zope Corporation
http://www.zope.org http://www.zope.com
"Killing hundreds of birds with thousands of stones"