Google App Engine cron with more than 1 minute frequency

Question

In Google App Engine crons, the highest frequency to call a handler is 1m. If we want a script to run more often, does it make sense to have two cron definitions each running at 1 min? Like below:

cron:

• description: cron1 url: /handle_info schedule: every 1 minute

• description: cron2 url: /handle_info schedule: every 1 minute

What are other good approaches?

Answer 1

You can fire a task using the Task Queue API that schedules another task using an eta < now + 1min.

Answer 2

I came up with an idea to use Cron jobs to execute my script more than once a minute.

Here's what I did: I created a cronjob to execute a file called cron.php Then inside of that file I changed the max execution time to 50 seconds And then I created a loop with a sleep command inside of it And each time the loop fires it includes the commands I need to run.

Here's the code:

<?PHP
ini_set('max_execution_time', 50);
require_once('includes/settings.php'); 

for ($i=1; $i<=5; $i++){
    include('commander.php');
    sleep(10);
}
?>

Answer 3

I created a 1 minute cron then used defer in the app engine code to raise another pubsub message

import logging
import webapp2
import time
import json
import pubsub_utils
from google.appengine.ext import ndb, deferred

def defer_post(item_key=None):
    try:
        logging.info('deferred pubsub')
        pubsub_utils.publish_to_topic(item_key, str(time.time()))
    except Exception as e:
        logging.info('item_key: %s', item_key)
        logging.exception(e)

class PushToPubSub(webapp2.RequestHandler):
    def get(self, topic):
        logging.info('cron pubsub: %s', topic)
        pubsub_utils.publish_to_topic(topic, str(time.time()))
        deferred.defer(defer_post, item_key=topic, _countdown=30)
        self.response.headers['Content-Type'] = 'application/json'
        self.response.write(json.dumps({"status": "200"}))

app = webapp2.WSGIApplication([
    webapp2.Route(r'/publish/<topic>', handler=PushToPubSub)
], debug=True)