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I can't get a scheduled task to run with Web2Py.

I have a web app, call it webapp1.

I want to do some maintenance activites on the database once a day with a function, call it cleandb().

I've tried to follow the articles on Scheduled Tasks but I'm not seeing my function run.

I can see in the Scheduled Task Log, that the script runs, but apparently the function cleandb() never runs.

This is what I've done:

Created a model file: scheduler.py with lines of code similar to this:

def cleandb():

    #Do stuff here.
    return

from gluon.scheduler import Scheduler

scheduler = Scheduler(db)

Created a file under my home directory called: start_task.py

It has code:

#/usr/bin/env python

import os

import socket

import subprocess

import sys

filename = os.path.abspath(__file__)  # we use this to generate a unique socket name

\# we use a local socket as a lock.

\# it can only be bound once, and will be released if the process dies

\# we want to keep the socket open until the very end of

\# our script so we use a global variable to avoid going

\# out of scope and being garbage-collected

lock_socket = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)

try:

    lock_socket.bind('\0' + filename)

except socket.error:

    print("Failed to acquire lock, task must already be running.")

    sys.exit()

subprocess.call(["python", "web2py/web2py.py", "-K", "webapp1"])

Then I created a Scheduled Task to run start_task.py

I can see in the Scheduled Task Log, that the script runs, but apparently the function cleandb() never runs.

How do I get it to run?

I thought that's what all of this was supposed to accomplish.

[edit by admin: formatting]

It looks like you're using two different schedulers there -- the scheduled task feature of PythonAnywhere and the gluon scheduler.

What happens if you just run

python web2py/web2py.py -K webapp1

...in a Bash console? I don't see anything in there that would specifically run your scheduler.py, though that may simply be me not understanding part of web2py.

Oh I see. Everything I read in the help forum mentioned using the Scheduled Tasks, etc. When I develop Web2Py apps locally, I can start and stop the scheduler from the launcher panel. There's no launcher panel on PythonAnywhere, so I thought I had to use these work-arounds they mention using the Scheduled Tasks, etc.

Let me look at this again...

OK. I think I understand this now.

I now have a Web2Py app running a task periodically.

For whoever else might need this, to run a periodic task using Web2Py's scheduler mechanism there are only 2 things to do:

.1. Create a model file, say scheduler.py

In it, put the definition of the function you want to run periodically and the two lines of boiler-plate code:

from gluon.scheduler import Scheduler

scheduler = Scheduler(db)

.2. Create a new record in the database table: scheduler_task

Enter the name of the function to run and the desired values for the task schedule.

--That's it.

Great! Glad you got it working.

Are you sure this is it? I have done everything as described and according to the web2py scheduler step by step video (https://vimeo.com/27478796) and still cant make it work. Don't I need somehow to run the scheduler with python web2py.py -K app_name ? many thanks,P

Yes, you need to run the scheduler. What happens when you do? Do you see that it has run in the web2py admin interface? Does it return an error?