WSGIDestroyInterpreter

Description:

Enable/disable cleanup of Python interpreter.

Syntax:

WSGIDestroyInterpreter On|Off

Default:

WSGIDestroyInterpreter On

Context:

server config

The WSGIDestroyInterpreter directive is used to control whether the Python interpreter is destroyed when processes are shutdown or restarted. By default the Python interpreter is destroyed when the process is shutdown or restarted.

This directive was added due to changes in Python 3.9 where the Python cleanup behaviour was changed such that it would wait on daemon threads to complete. This could cause cleanup of the Python interpreter to hang in some cases where threads were created external to Python, as is the case where Python is embedded in a C program such as mod_wsgi with Apache.

If you observe daemon processes hanging at shutdown or restart, set this directive to Off to skip Python interpreter destruction:

WSGIDestroyInterpreter Off

Skipping interpreter destruction means Python atexit handlers and any other code registered to run during interpreter finalisation will not run. For most WSGI applications this is acceptable, since the daemon process is about to exit anyway and the operating system will reclaim its resources.

If an application genuinely needs to run cleanup code on process shutdown and WSGIDestroyInterpreter Off may be in effect, register the cleanup callback via mod_wsgi.subscribe_shutdown() instead of atexit. subscribe_shutdown callbacks are dispatched by mod_wsgi directly before interpreter destruction is attempted and therefore run regardless of this setting. See Registering Cleanup Code for usage.