In this post, let's have a look at how we can execute any Actions with Retries using Polly. It's actually quite easy.
Rather than explaining in words, a code sample would greatly explain itself.
Say I have this custom exception, so whenever I received this exception, let's say I want to add some retry logic.
public class MyCustomException : Exception
{
public MyCustomException(string message) : base(message)
{
}
}
So I can create a Retry Policy and just execute whatever our action within the policy. (here I am just using the async counterpart since that what we are using almost all the time).
using Microsoft.Extensions.Logging;
using Polly;
using Polly.Retry;
using System;
using System.Threading.Tasks;
namespace ConsoleApp1
{
class Program
{
static async Task Main(string[] args)
{
using ILoggerFactory loggerFactory = LoggerFactory.Create(builder =>
{
builder.AddConsole();
});
ILogger<Program> logger = loggerFactory.CreateLogger<Program>();
AsyncRetryPolicy policy = CreatePolicyFor<MyCustomException>(logger);
await policy.ExecuteAsync(async () =>
{
await DoSomething();
});
}
private static async Task DoSomething()
{
throw new MyCustomException("Some Exception");
}
private static AsyncRetryPolicy CreatePolicyFor<TException>(ILogger logger, int retries = 3, int delayInSecods = 5) where TException : Exception
{
return Policy
.Handle<TException>()
.WaitAndRetryAsync(
retryCount: retries,
sleepDurationProvider: retry => TimeSpan.FromSeconds(delayInSecods),
onRetry: (exception, timeSpan, retry, ctx) =>
{
logger.LogWarning(exception,
"Exception {ExceptionType} with message {Message} detected on attempt {retry} of {retries}",
exception.GetType().Name,
exception.Message,
retry,
retries);
}
);
}
}
}
We can specify how many retries we want, the sleep duration between retries, and nicely, we can even specify an Action to be executed when retrying (like I am logging the attempt info here).
Hope this helps!
Happy Coding.
Regards,
Jaliya
