ApplicationError2 and ApplicationError5 when commu

Question

I have built an application on google app engine, in python27 to connect with another services API and in general everything works smoothly. Every now and then I get one of the following two errors

(<class 'google.appengine.api.remote_socket._remote_socket.error'>, error('An error occured while connecting to the server: ApplicationError: 2 ',), <traceback object at 0x11949c10>)

(<class 'httplib.HTTPException'>, HTTPException('ApplicationError: 5 ',), <traceback object at 0x113a5850>)

The first of these errors (ApplicationError: 2) I interpret to be an error occurring on the part of the servers with which I am communicating, however I've not been able to find any detail on this and if there is any way I am responsible / can fix it.

The second of these errors (ApplicationError: 5) I've found some detail on and it suggests that the server took too long to communicate with my application - however I've set the timeout to be 20s and it fails considerably quicker than that.

If anyone could offer links or insight into the errors - specifically what causes the error and what can be done to fix it I'd very much appreciate it.

Answer 1

You get to start using the word "idempotent" in casual conversations and curses :)

The only thing you can do is to try the call again, and accept the fact that your initial call may have gone through, only to time out on the response - i.e. if the call actually did something (create a customer order for example), after the timeout error you might have to check if the first request succeed so you don't end up with multiple copies of the same order.

Hope that makes sense. FWIW we work with some unfriendly API's and for us, about 80% of our code is dealing with exactly this sort of !@#$%.