How to profile Google App Engine python27 runtime (not python)

google-app-engine, profile, python, python-2.7

Solution

You can profile a WSGI app using WSGI middleware by inserting in your appengine_config.py:

import cProfile
import cStringIO
import logging
import pstats

def webapp_add_wsgi_middleware(app):

  def profiling_wrapper(environ, start_response):
    profile = cProfile.Profile()
    response = profile.runcall(app, environ, start_response)
    stream = cStringIO.StringIO()
    stats = pstats.Stats(profile, stream=stream)
    stats.sort_stats('cumulative').print_stats()
    logging.info('Profile data:\n%s', stream.getvalue())
    return response

  return profiling_wrapper

Problem

How to profile python code under Google App Engine runtime python27? In runtime python it was done by this code - python runtime: ``` from google.appengine.ext import webapp class PageHandler(webapp.RequestHandler): def get(self): self.response.headers['Content-Type'] = 'text/plain' self.response.out.write('Hello, WebApp World!') def real_main(): application = webapp.WSGIApplication([('/', PageHandler)], debug=True) run_wsgi_app(application) def profile_main(): # This is the main function for profiling # We've renamed our original main() above to real_main() import cProfile, pstats, StringIO prof = cProfile.Profile() prof = prof.runctx('real_main()', globals(), locals()) stream = StringIO.StringIO() stats = pstats.Stats(prof, stream=stream) stats.sort_stats('cumulative') logging.info("Profile data:\n%s", stream.getvalue()) if __name__ == "__main__": profile_main() ``` In runtime python27 is has to be done differently since there is no main calls - how to do the same thing - I want to switch to python27 but not without profiling. How to attach profiler in python27 - python27 runtime? ``` import webapp2 class PageHandler(webapp2.RequestHandler): def get(self): self.response.headers['Content-Type'] = 'text/plain' self.response.out.write('Hello, WebApp World!') app = webapp2.WSGIApplication([('/', PageHandler)]) ```

Original source