CODEWITHSUNDEEP
javagoogle-app-engine
sockeqwe
sockeqwe

Reputation: 15919

Schedule Tasks in AppEngine

I use appengine (java) as a backend for a mobile app (android). The user of my app can create public events consisting of a title and a date/time. Those events are stored on my appengine backend. Any user can subscribe for events and will receive a push notification at that time the events starts.

So I want to schedule a job / task on appengine to run at the events date/time to send a push notification to all subscribers.

Example: User A creates an event that will start on Saturday next week on 8 pm. User B and User B subscribe for this event. On Saturday 8 pm a job/task should start to send the push notifications to User B and User C to inform that the event has started.

My question is: How do I implement something like this in an efficient way on appengine? I want to say, start a Task for the Event on Saturday at 8 pm. There are Cronjobs and TaskQueues. Cronjobs can not be created programmatically. TaskQueue needs to be pulled and can not be scheduled to pull at a given date / time, right? So the only solutions I see is to create a cronjob that will run every minute to check if there is a Event that starts right now.

An event can be created at any time and any day in the week. However the most events are created for the weekend and There are days when no event has been created for. So running a cronjob periodically ever minute is very inefficient. Im looking for a smarter solution, any ideas?

Upvotes: 2

Views: 349

Answers (1)

Thanos Makris
Thanos Makris

Reputation: 3115

Indeed, based on your description, the solution is to create a cron job that checks for new events that start right now.

However, you should be careful not to exceed the 60 second window you have for each cron job. If you have a lot of events, you probably should move the actual processing from the cron job to background tasks using Push Task Queues.

You may take a look to this post for a combination of cron jobs and Task Queues.

Upvotes: 3

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