I am looking for a python webserver which is multithreaded instead of being multi-process (as in case of mod_python for apache). I want it to be multithreaded because I want to have an in memory object cache that will be used by various http threads. My webserver does a lot of expensive stuff and computes some large arrays which needs to be cached in memory for future use to avoid recomputing. This is not possible in a multi-process web server environment. Storing this information in memcache is also not a good idea as the arrays are large and storing them in memcache would lead to deserialization of data coming from memcache apart from the additional overhead of IPC.
I implemented a simple webserver using BaseHttpServer, it gives good performance but it gets stuck after a few hours time. I need some more matured webserver. Is it possible to configure apache to use mod_python under a thread model so that I can do some object caching?
Consider reconsidering your design. Maintaining that much state in your webserver is probably a bad idea. Multi-process is a much better way to go for stability. 
Is there another way to share state between separate processes? What about a service? Database? Index? 
It seems unlikely that maintaining a huge array of data in memory and relying on a single multi-threaded process to serve all your requests is the best design or architecture for your app.
A good multithreaded python webserver?