About

Scheduler service is very simple app that lets you define HTTP invocation scheduler for your site.

Google App Engine is great tool for amateur web developers - it's free, it's easy and it's reliable. It's really pleasure to develop apps for Google App Engine.

However, GAE is still new and lacks lot's of functionalities other sites and frameworks have.

One of other apps I'm developing needs to send reminder emails to users after some time of inactivity. If one of users lags with their work for some time, they should receive notification with report with what and for how long they lag.
It's straightforward to implement in typical web application framework or at least (if framework lacks this functionality) on the same machine original app is deployed.
But Google App Engine lacks scheduler utility - your code is executed only when user request a page from your application.
It's quite easy to get around this limitation. Simply put your scheduler task in url handler and call that handler periodically from external machine (for example - with crontab and wget).
But this requires you have machine connected to internet. And the whole point of using GAE is to use Google servers for deployment, so that you don't have to maintain your own machines or resources.

That's where SchedulerService GAE app can help.

Scheduler Service let's you define schedulers that will periodically fetch url's you specify. Management app is hosted on GAE, and scheduler agents (parts of the app that actually actively fetch the urls) sit on multiple machines scaterred across the globe. Agents contact GAE app and get info about what urls should be called and when. This way you don't have to maintain a program/script/crontab entry that calls your web application periodically.

See Help for more in-depth explanation of how Scheduler Service works.

If you have any questions, please mail me at mpietrzak@gmail.com. If you like this app, you might be interested in other stuff I'm working on.