Problem : Instance Variable or Application Constant Expiring

[CJ]

Problem : Instance Variable or Application Constant Expiring

I am parsing an XML, and getting a response object which is quite
large ,hence I cant store that in Session or cookie.
I can not regenerate this response as its from a 3rd party Web
service . Regeneration would spoil the flow of the application.

I have used 3 approaches .
@instance_variable
@@class_variable
$CONSTANT

Limitations:
Application doesn't have a
- Database
- Filestore system

Can someone please let me know a solution by which I can persist a
large string around 10000 to 25000 characters throughout the
application, also which is user specific and not same for all users.

To repeat: I need a way by which I can store a large data(10k -25K
characters) throughout the application.

Approach I followed:
Like mentioned above I have used a $CONSTANT or @@class_variable ,
this approach works fine with mongrel/webrick both locally or on
server(linux). however the same piece of code fails on passenger .

RAILS version (3.0.3 and 3.1.0)
Ruby (1.9.2)