Mod_wsgi + pymssql access to SQL Server blocking

When accessing SQL Server through Pymssql, there was no problem running directly in Python, and when deployed through Mod_wsgi and Apache, all requests were found to hang over the database query.

Through Google to find the answer, thank you Google, detailed description please see: Https://code.google.com/p/modwsgi/wiki/ApplicationIssues#Python_Simplified_GIL_State_API

Briefly, Mod_wsgi creates a sub interpreter for each virtual host and app mount point. There is a famous Gil in Python, when access to the Gil State via C extension, only the first sub interpreter works, and if using subsequent sub interpreter results in deadlocks or crash, Because Pymssql is a C extension so there is this problem, the solution is to add configuration items:

Wsgiapplicationgroup%{global}

Force the app to use the first sub interpreter, which makes the Gil work properly. After the change, mod_wsgi everything OK.