A good multithreaded python webserver?

Question

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?

Answer 1

You could instead use a distributed cache that is accessible from each process, memcached being the example that springs to mind.

Answer 2

CherryPy. Features, as listed from the website:

• A fast, HTTP/1.1-compliant, WSGI thread-pooled webserver. Typically, CherryPy itself takes only 1-2ms per page!
• Support for any other WSGI-enabled webserver or adapter, including Apache, IIS, lighttpd, mod_python, FastCGI, SCGI, and mod_wsgi
• Easy to run multiple HTTP servers (e.g. on multiple ports) at once
• A powerful configuration system for developers and deployers alike
• A flexible plugin system
• Built-in tools for caching, encoding, sessions, authorization, static content, and many more
• A native mod_python adapter
• A complete test suite
• Swappable and customizable...everything.
• Built-in profiling, coverage, and testing support.

Answer 3

Twisted can serve as such a web server. While not multithreaded itself, there is a (not yet released) multithreaded WSGI container present in the current trunk. You can check out the SVN repository and then run:

twistd web --wsgi=your.wsgi.application

Answer 4

Not multithreaded, but twisted might serve your needs.

Answer 5

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.