Question

Have some problems using taskqueues in google app engine. I tried doing the same as in this site:
https://developers.google.com/appengine/docs/python/taskqueue/overview-push

But it seems like my task is never executed, I get this error:

WARNING 2012-11-25 15:29:21,258 taskqueue_stub.py:1978] Task task1 failed to execute. This task will retry in 12.800 seconds

The code is mainly the same except of these:

class CounterWorker(webapp.RequestHandler):
  def init(self): # should run at most 1/s
    def txn():
      logging.info("bla")
    db.run_in_transaction(txn)

and I just add the task like this:

taskqueue.add(url='/worker')

What I really want is just running a block of code that dont timeouts. So I read I could use taskqueues. But I cant seem to make it work.

Answer 1

If you just want to execute tasks “vanilla” then have a look at the deferred functions.

Background work with the deferred library

from google.appengine.ext import deferred

  def do_something_expensive(a, b, c=None):
      logging.info("Doing something expensive!")
      # Do your work here

  # Somewhere else
  deferred.defer(do_something_expensive, "Hello, world!", 42, c=True)

You won’t need a url/webapp handler as you can pass the function directly.