How do I break up high-cpu requests on Google App Engine?

Question

To give an example of the kind of request that I can't figure out what else to do for:

The application is a bowling score/stat tracker. When someone enters their scores in advanced mode, a number of stats are calculated, as well as their score. The data is modeled as:

Game - members like name, user, reference to the bowling alley, score Frame - pinfalls for each ball, boolean lists for which pins were knocked down on each ball, information about the path of the ball (stance, target, where it actually went), the score as of that frame, etc GameStats - stores calculated statistics for the entire game, to be merged with other game stats as needed for statistics display across groups of games.

An example of this information in practice can be found here.

When a game is complete, and a frame is updated, I have to update the game, the frame, every frame after it and possibly some before it (to make sure their scores are correct), and the stats. This operation always flags the CPU monitor. Even if the game isn't complete, and statistics don't need to be calculated, the scores and such need to be updated to show the real-time progress to the user, and so these also get flagged. The average CPU time for this handler is over 7000 mcycles, and it doesn't even display a view. Most people bowl 3 to 4 games per series - if they are entering their scores realtime, at the lanes, that's about 1 request every 2 to 4 minutes, but if they write it all down and enter it later, there are 30-40 of these requests being made in a row.

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As requested, the data model for the important classes:

class Stats(db.Model):
  version = db.IntegerProperty(default=1)
  first_balls=db.IntegerProperty(default=0)
  pocket_tracked=db.IntegerProperty(default=0)
  pocket=db.IntegerProperty(default=0)
  strike=db.IntegerProperty(default=0)
  carry=db.IntegerProperty(default=0)
  double=db.IntegerProperty(default=0)
  double_tries=db.IntegerProperty(default=0)
  target_hit=db.IntegerProperty(default=0)
  target_missed_left=db.IntegerProperty(default=0)
  target_missed_right=db.IntegerProperty(default=0)
  target_missed=db.FloatProperty(default=0.0)
  first_count=db.IntegerProperty(default=0)
  first_count_miss=db.IntegerProperty(default=0)

  second_balls=db.IntegerProperty(default=0)
  spare=db.IntegerProperty(default=0)
  single=db.IntegerProperty(default=0)
  single_made=db.IntegerProperty(default=0)
  multi=db.IntegerProperty(default=0)
  multi_made=db.IntegerProperty(default=0)
  split=db.IntegerProperty(default=0)
  split_made=db.IntegerProperty(default=0)

class Game(db.Model):
  version = db.IntegerProperty(default=3)
  user = db.UserProperty(required=True)
  series = db.ReferenceProperty(Series)
  score = db.IntegerProperty()
  game_number = db.IntegerProperty()
  pair = db.StringProperty()
  notes = db.TextProperty()
  simple_entry_mode = db.BooleanProperty(default=False)
  stats = db.ReferenceProperty(Stats)
  complete = db.BooleanProperty(default=False)

class Frame(db.Model):
  version = db.IntegerProperty(default=1)
  user = db.UserProperty()
  game = db.ReferenceProperty(Game, required=True)
  frame_number = db.IntegerProperty(required=True)
  first_count = db.IntegerProperty(required=True)
  second_count = db.IntegerProperty()
  total_count = db.IntegerProperty()
  score = db.IntegerProperty()
  ball = db.ReferenceProperty(Ball)
  stance = db.FloatProperty()
  target = db.FloatProperty()
  actual = db.FloatProperty()
  slide = db.FloatProperty()
  breakpoint = db.FloatProperty()
  pocket = db.BooleanProperty()
  pocket_type = db.StringProperty()
  notes = db.TextProperty()
  first_pinfall = db.ListProperty(bool)
  second_pinfall = db.ListProperty(bool)
  split = db.BooleanProperty(default=False)

Answer 1

A few suggestions:

• You could store the stats for frames as part of the same entity as the game, rather than having a separate entity for each, by storing it as a list of bitfields (stored in integers) for the pins standing at the end of each half-frame, for example. Let me know if you want more details on how this would be implemented.
• Failing that, you can calculate some of the more interrelated stats on fetch. For example, calculating the score-so-far ought to be simple if you have the whole game loaded at once, which means you can avoid having to update multiple frames on every request.
• We can be of more help if you show us your data model. :)