Polly: Throw on final exception

Created on 14 Sep 2018 · 5Comments · Source: App-vNext/Polly

Hi,

Is it possible to throw the exception if the final Retry Fails? I am using the WaitAndRetryAsync, but I wish to throw the exception if the final retry throws and exception.

I can see the CircuitBreaker throws the exception but is it possible waiting before retries?

Thanks in advance!

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grik001

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Most helpful comment

Hi @grik001 . Happy to look at any code if you can post a repro. Here within Polly is a unit test demonstrating that WaitAndRetryAsync does rethrow the final exception.

Couple of things that could cause a final exception not to be rethrown:

.ExecuteAsync(...), like any async API, returns Task. If the result of .ExecuteAsync(...) isn't awaited, then the exception will remain captured on the Task rather than rethrown.
If using .ExecuteAndCaptureAsync(...), then the design intent of that is to capture any final exception into the FinalException property. .ExecuteAndCaptureAsync(...) captures any final exception, whereas .ExecuteAsync(...) rethrows it.

reisenberger on 15 Sep 2018

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Hi @grik001

Is it possible to throw the exception if the final Retry Fails?

That is exactly what the library does by default - see how retry works in the wiki.

Let me know if I've not understood the question, and you're after something slightly different!

reisenberger on 14 Sep 2018

I will test this again, but I am sure that WaitAndRetryAsync was blocking the exception even if the last try does not succeed.

grik001 on 14 Sep 2018

Hi @grik001 . Happy to look at any code if you can post a repro. Here within Polly is a unit test demonstrating that WaitAndRetryAsync does rethrow the final exception.

Couple of things that could cause a final exception not to be rethrown:

.ExecuteAsync(...), like any async API, returns Task. If the result of .ExecuteAsync(...) isn't awaited, then the exception will remain captured on the Task rather than rethrown.
If using .ExecuteAndCaptureAsync(...), then the design intent of that is to capture any final exception into the FinalException property. .ExecuteAndCaptureAsync(...) captures any final exception, whereas .ExecuteAsync(...) rethrows it.