How to throw final error using WaitAndRetry and Execute?

Question

I'm, trying to check a simple WaitAndRetry of Polly

class Program
{
    public static void Main()
    {
           
        int i = 0;
        var _retryPolicy = Policy
       .Handle<Exception>()
        .WaitAndRetry(Backoff.ExponentialBackoff(TimeSpan.FromSeconds(2), 10),
           (exception, timespan) =>
           {
               Console.WriteLine($"Retry: {timespan}. \n ex: {exception}");
           });

        _retryPolicy.Execute(() =>
        {
            Console.WriteLine(i);
            i++;
            int.Parse("something");
        });

        Console.ReadLine();
    }
}   

And I want to throw a final exception after all the retries are failed. How can I do it?

Excepted Result:

Retry: ..

Retry: ..

Retry: ..

My new final error!

Thank You!

Answer 1

You don't have to explicitly re-throw the last exception.

The retry works in the following way:

• If an exception is thrown by the decorated method and there is a related .Handle<TEx> or .Or<TEx> clause inside the policy definition then it checks if the retry limit has been reached or not
  • If the retry limit has not been exceeded then it will perform yet another retry attempt
  • If the retry limit has been reached then it will throw the last exception
• If there is not related .Handle<TEx> or .Or<TEx> clause then it will throw the last exception

Here is a diagram from the official documentation

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Please also note that if you run your application in a debug mode then the IDE might stop each time when the decorated method throws exception. It depends on your IDE settings.