I am trying to create a session on Heroku with 1000+ participants and it is taking very very long (at the time of writing I am at ~1.5hrs). It is a single player app with 55 rounds. Each player plays against 19 'bots', which I coded using the ExtraModel class following the example here: https://s3.amazonaws.com/otreehub/browsable_source/d7188187-cdba-4c61-ae3a-d7cc3d6fcde9/bots_vs_humans_complex/__init__.py.

Here is my code for creating_session:

class Subsession(BaseSubsession):
    counter = models.IntegerField(initial=1)

    def creating_session(self):
        players = self.get_players()
        for player in players:
            for bot in range(C.BOTS_PER_GROUP):
                MyBot.create(player=player, agent_id=bot + 1)
            
(C.BOTS_PER_GROUP equals 19 in the above.)

Is this expected, and how could it be sped up?

How many variables do you have in Player model?

Oh, sorry just saw you posted the code. Maybe someone will have better advice, but have you considered trying to make it a single round as a Live Page? I have also used the jspsych integration in oTree to make everything one page, but that would probably be more work.

There are 4 boolean, 8 integer, 4 float and 1 string variables in the player model (in addition to the built in variables). The MyBot ExtraModel class has a similar number of variables.

I did not quite understand how ExtraModel is handled in the documentation, does it require a similar amount of memory as players? In other words, if I have 1000 players, each having 19 ExtraModels, is it like having 20000 players? That could perhaps be the issue.