WSGIApplicationGroup

WSGIApplicationGroup is a directive used by mod_wsgi, the Apache module that serves Python WSGI applications. It controls which Python sub-interpreter will execute a given WSGI application within the server process. By assigning applications to specific interpreter groups, administrators can isolate code that relies on non-thread-safe extensions or altered global state while sharing a single process and worker pool.

WSGIApplicationGroup works alongside WSGIProcessGroup, which selects the operating system process group running the application. Together, these directives let administrators tune isolation, memory usage, and startup cost. Applications that require separate interpreter environments can be placed in distinct groups, reducing cross-application interference without multiplying processes.

Configuration is typically per virtual host or per WSGI application in the server's configuration file. A value may reference a named sub-interpreter group, or use a special token such as GLOBAL to indicate the global interpreter. If omitted, mod_wsgi applies a default that may share an interpreter across multiple applications.

Changing WSGIApplicationGroup can affect compatibility and performance, especially for extensions with internal state or for threaded workloads. Thorough testing is advised when adjusting these settings.

See also: WSGIProcessGroup, mod_wsgi, Python sub-interpreters.