Useful stuff, thanks! Just yesterday I was looking into this same issue. I was wondering if plain 0.96 Django use (without appengine helper or patch) would be significantly faster, and your post really makes me want to try that. I changed the handling of a single url in my app to be a "plain" GAE (webapp.WSGIApplication) handler. This URL was for a cron-triggered task that runs every minute. In the absence of other traffic this resulted in a cold start every minute and this processing this trivial request now only uses approx. 200 ms CPU quota. When it was part of the main Django app, it would take over 2000 ms CPU quota.
BTW I'm fairly convinced that memcached data doesn't get flushed out. On Mar 24, 6:27 am, cz <[email protected]> wrote: > I added some timing code to see how expensive a cold app startup is. > This is a Django1.x app so YMMV. > > The typical numbers are: > > Zipimport of Django: 180ms > Appengine-django-helper monkeypatching: 430ms > Misc imports, app-specific patching, etc: 20ms > ------------------------------------------------------------------------ > Total app startup: 630ms > > This is for startup only, not the time it takes to then process the > request, so this is a fixed expense. Also, this is real time not cpu > quota time which is much higher. > > The biggest hog is the django-helper monkeypatcher. I'm eventually > going to try appengine-patch with the hope that it will be faster. > > Additionally, on a cold startup my app processes a request in about > 500ms, but on a warm app it only takes 10ms due to some aggressive > caching. I think that when all your app instances expire so does all > it's memcached data. > > If anybody has done something similar and found different numbers > please post the results and let me know what I did wrong. > > Here's the main.py I'm using in case you'd like to point out any > errors in my methodology: > ---------------------------------------- > > from time import clock > t_main_start = clock() > > # Standard Python imports. > import os > import sys > import logging > import settings > > logging.getLogger().setLevel(settings.LOGGING_LEVEL) > > # Fix (hack) for missing unlink > if os.name == 'nt': > os.unlink = lambda: None > > # TODO (after gathering stats): remove this since appengine_django > does it for us > # Import Django 1.x from a zipfile and get rid of v.96. > t_zip_start = clock() > django_zip_path = os.path.abspath('django.zip') > if django_zip_path not in sys.path: > sys.path.insert(0, django_zip_path) > for k in [k for k in sys.modules if k.startswith('django')]: > del sys.modules[k] > # TODO (after gathering stats): remove this line > from django import template # provoke django zipimport > t_zip = (clock() - t_zip_start) * 1000 > > # Install appengine_django. Patches Django 1.x for use with GAE > t_patch_start = clock() > from appengine_django import InstallAppengineHelperForDjango > InstallAppengineHelperForDjango() > t_patch = (clock() - t_patch_start) * 1000 > > # Patch the appengine_django patch to fix User object creation > # Remove this when switching to appengine-patch > from monkeypatch import patch > patch() > > # Google App Engine imports. > from google.appengine.ext.webapp import util > > # Import the part of Django that we use here. > import django.core.handlers.wsgi > > t_main = (clock() - t_main_start) * 1000 > logging.info('[TIME] main.py startup: %.1fms (zipimport: %.1fms, > appengine-django: %.1fms)' % (t_main,t_zip,t_patch)) > > def real_main(): > t_request_start = clock() > # Create a Django application for WSGI. > application = django.core.handlers.wsgi.WSGIHandler() > > # Run the WSGI CGI handler with that application. > util.run_wsgi_app(application) > t_request = (clock() - t_request_start) * 1000 > logging.info('[TIME] request: %.1fms' % t_request) > > def profile_main(): > # Rename this to main() for profiling > import cProfile, pstats > prof = cProfile.Profile() > prof = prof.runctx("real_main()", globals(), locals()) > print "<pre>" > stats = pstats.Stats(prof) > stats.sort_stats("time") # Or cumulative > stats.print_stats(80) # 80 = how many to print > # The rest is optional. > #stats.print_callees() > #stats.print_callers() > print "</pre>" > > main = real_main > > if __name__ == '__main__': > main() --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
