Deferred example

app.yaml

@@ -26,6 +26,9 @@ handlers:
 - url: .*  # This regex directs all routes to main.app
   script: main.app
 
+builtins:
+- deferred: on
+
 # Third party libraries that are included in the App Engine SDK must be listed
 # here if you want to use them.  See
 # https://developers.google.com/appengine/docs/python/tools/libraries27 for

main.py

@@ -6,20 +6,41 @@
 # Note: We don't need to call run() since our application is embedded within
 # the App Engine WSGI application server.
 
+from google.appengine.ext import ndb
+from google.appengine.ext import deferred
+
+class Counter(ndb.Model):
+  count = ndb.IntegerProperty(indexed=False)
+
+def reset():
+  ndb.delete_multi(Counter().query().fetch(keys_only=True, use_cache=False, use_memcache=False))
+
+def increment():
+  counter = Counter().query().get(use_cache=False, use_memcache=False)
+  if not counter:
+    counter = Counter(count=0)
+
+  counter.count += 1
+  counter.put()
+
+  if counter.count < 10:
+    deferred.defer(increment)
 
 @app.route('/')
 def hello():
-    """Return a friendly HTTP greeting."""
-    return 'Hello World!'
+  """Return a friendly HTTP greeting."""
+  reset()
+  deferred.defer(increment)
+  return 'Hello World!'
 
 
 @app.errorhandler(404)
 def page_not_found(e):
-    """Return a custom 404 error."""
-    return 'Sorry, Nothing at this URL.', 404
+  """Return a custom 404 error."""
+  return 'Sorry, Nothing at this URL.', 404
 
 
 @app.errorhandler(500)
 def application_error(e):
-    """Return a custom 500 error."""
-    return 'Sorry, unexpected error: {}'.format(e), 500
+  """Return a custom 500 error."""
+  return 'Sorry, unexpected error: {}'.format(e), 500