We have an nginx instance sitting in front of apache 2 (nginx handles static resources, dynamic content requests get proxied to apache) which is primarily using mod_wsgi to server various python/django apps.
We have suddenly seeing a high server load (steadily climbing to more than 50, normally it's less than 1) and are looking for the best ways to track down the cause.
Is there a way to see which virtual hosts are responsible for the apache processes?
Some general tips in diagnosing the cause of high server load would be welcome too.
Edit: Thanks to everyone for their help, it turned out to be caused by a code error and no server reconfiguration was necessary. However, the tips provided will be useful in the future.