Question

I’ve noticed occasionally that my Drive SDK calls fail periodically with a 500 error, retrying the request usually fixes the error immediately. Looking at the Google documentation, its recommended to use the exponential back off technique, I wrote my own implementation which works fine, however while debugging I happened to bump into the interface BackOffPolicy, with more investigation I even found the implementation ExponentialBackOffPolicy.

So instead of managing this myself, I thought best to remove my implementation and let the SDK do it for me. The backoff policy can (from my knowledge) be set with a built HTTP request, so its quite easy to use when manually building requests or when using batch requests, however I cannot seem to find the easiest place to inject this when using the core SDK, for example, if I want to set a backoff policy for:

drive.files().get(id).execute();

I cannot do something like:

drive.files().get(id)
     .setBackOffPolicy(new ExponentialBackOffPolicy())
     .execute();

I would need to do this:

drive.files().get(id)
     .buildHttpRequest()
     .setBackOffPolicy(new ExponentialBackOffPolicy())
     .execute();

However if I do that, then I would also need to reproduce the parsing logic of the execute method of Drive.Files.Get and convert the result to a File object which is obviously not an ideal approach. Is there an easier way to “generically” add this to the request or perhaps a way to set a default back off policy for all requests?

If not, perhaps this could be introduced into a future version of the Drive SDK?

Thanks,
David

Answer 1

AFAIK Google made Exponential Backoff is only used when downloading or uploading content in the drive Java API. You need your own implementation for the other requests.

What I did to implement it for any request is wrap a Callable executing once the request and letting the wrapper class do the exception handling and repeating of the request.