Incendium.RetryPolicy 1.0.2

Incendium.RetryPolicy

Incendium.RetryPolicy is a small .NET standard 2.1 library that provides a RetryHttpClientHandler type to easily retry HTTP requests in case of errors, as well as a RateGate to manage rate limiting.

Getting started

Installation

PM> Install-Package Incendium.RetryPolicy

RetryHttpClientHandler

Сan be used as a handler for HttpClient and allows you to easily set up repeated requests with constant or exponential delays in the following cases:

• HttpNetworkException
• Server errors (5xx)
• Request timeout error (408)
• Too many requests (429)

and also allows you to configure rate limiting using RateGate:

var innerHttpClientHandler = new HttpClientHandler(); // can be easily mocked
var retryHttpClientHandler = new RetryHttpClientHandler(innerHttpClientHandler)
{
    RetryCount = 5, // sets 5 retry attempts
    RetryOnHttpRequestException = true, // sets the retry flag in case of an HttpRequestException
    FirstRetryDelay = TimeSpan.FromMilliseconds(100), // sets the median starting delay between requests
    RateGate = new RateGate(
        occurrences: 10, // sets rate limit to 10 request per 60 seconds
        timeUnit: TimeSpan.FromSeconds(60))
}
var httpClient = new HttpClient(retryHttpClientHandler);

There are several ready-made delay algorithms that can be used:

• Constant
• Exponential
• DecorrelatedJitterBackoffV2 (default)

var retryHttpClientHandler = new RetryHttpClientHandler(innerHttpClientHandler)
{
    RetryDelaysFactory = () => Delays.Exponential(
        firstDelay: TimeSpan.FromMilliseconds(100),
        count: 10)
}

You can also pass your own delay algorithm in the RetryDelaysFactory property, which should return IEnumerable<TimeSpan>.