Cannot create Timer class in backend AppEngine instance...why?

Question

I am able to create threads however creation of a Timer and scheduling it are eluding me. I am unsure why this is failing...and silently!

Any ideas?

Make sure you create threads via Google provided ThreadManager: https://developers.google.com/appengine/docs/java/javadoc/com/google/appengine/api/ThreadManager — Peter Knego, Apr 17 '13 at 19:08

score 0 · Answer 1 · edited May 23 '17 at 12:28

0

You can use threads in GAE, but there are limitations:

You must create them via GAE provided ThreadManager.
On frontend instances threads can not outlive requests. This means that Timer started from a http request can not run TimerTask if the request already ended - I guess this is why it silently fails.

If you need to start a delayed task, try using DeferredTask (here's an example) with ETA setting.

edited May 23 '17 at 12:28

Community

answered Apr 17 '13 at 19:24

Peter Knego

I already have threading abstractions in my application which for AppEngine servers create threads in this manner. I have exposed backend to user requests so this has nothing to do with frontend. Perhaps they aren't creating Timers using appropriate threading API...if there are no changes to JRE then I guess this is the case. – user2292134 Apr 17 '13 at 20:45
Dang...it appears Thread.sleep is a no-go...kind of hard to roll your own timer. I am not seeing option in queue classes for simulating scheduling of thread. – user2292134 Apr 17 '13 at 21:53

1 Answers1