(2009-10-17) Spawning

Spawn Ing is a fast, easy to use, and flexible HTTP server (Web Server) for hosting Python web applications which conform to the WSGI interface. Spawning uses eventlet to do non-blocking I/O for http requests and responses. This means the server will scale to a large number of idle keep-alive connections easily. Spawning can be configured to use multiple OS processes and either POSIX threads or eventlet's green threads, which are implemented using greenlet... If your wsgi applications store state in memory, Spawning can be configured to run only one Python process. In this configuration your application state will be available to all requests but your application will not be able to take full advantage of multiple processors. Using multiple processes will take advantage of all processors and thus should be used for applications which do not share state... If your wsgi applications perform a certain subset of blocking calls which have been monkeypatched by eventlet to cooperate instead (such as operations in the socket module), you can configure each process to run only a single main thread and cooperate using eventlet's green threads instead. This can be useful if your application needs to scale to a large number of simultaneous open connections, such as a Comet server or an application which uses AJAX polling. However, most existing wsgi applications will probably perform blocking operations (for example, calling database adapter libraries which perform blocking socket operations). Therefore, for most wsgi applications a combination of multiple processes and multiple threads will be ideal.