RESTSchemaRetry is a .NET library that implements a simple Schema-Retry pattern in REST API context to enhance application resilience. A Schema-Retry handles transient failures when attempting to connect to a service or network resource by transparently retrying failed operations.
RESTSchemaRetry implements a straightforward retry mechanism with a delay, managing communication timeouts or service errors transparently to the application. The retry mechanism checks the HTTP response code to determine whether the error is transient or not.
Below is the list of potentially transient errors handled by RESTSchemaRetry:
- TooManyRequests
- InternalServerError
- BadGateway
- ServiceUnavailable
- GatewayTimeout
- InsufficientStorage
- RequestTimeout
- HttpVersionNotSupported
- NetworkAuthenticationRequired
-
Constant Backoff: The delay between retries is constant and does not change. This is a simple approach where each retry attempt waits for a fixed amount of time, defined by a
RetryDelayparameter. -
Linear Backoff: The delay between retries increases linearly. Each retry attempt waits longer than the previous one by a fixed increment. The delay is calculated as
RetryDelay * (retry + 1). -
Exponential Backoff: The delay between retries grows exponentially. The delay is calculated using a power of 2, multiplied by the base RetryDelay. This approach is useful to quickly back off from a failing operation, reducing server load. Formula:
RetryDelay * (2 ^ retry). -
Exponential Backoff with Jitter: Similar to exponential backoff, but with added randomness ("jitter") to the delay to avoid synchronized retries from multiple clients, which can cause spikes in traffic. The delay is calculated as
RetryDelay * (2 ^ retry) * random_factor, whererandom_factoris a random value between 0 and 1. -
Fibonacci Backoff: The delay between retries follows the Fibonacci sequence. This provides a middle ground between linear and exponential backoff, growing less aggressively than exponential. The delay is calculated as
RetryDelay * Fibonacci(retry). -
Randomized Backoff: The delay is randomly chosen between a minimum and a maximum range, usually defined as a multiple of RetryDelay. This helps to distribute retries more evenly over time, avoiding bursts of traffic. The delay is calculated randomly within a range, e.g.,
[RetryDelay, RetryDelay * 2].
To use the RESTSchemaRetry library, just create a RetryClient specifying the base URL and the resource. There are multiple constructor to specify the REST API parameters.
var retryClient = new RetryClient("https://example.com/","resource");at this point the REST API requests can be performed. For example, below how to execute a POST request:
var response = retryClient.Post<T>(objectToPost);Alternatively, you can register the library via dependency injection as follows:
builder.Services.AddRetryClient("https://your-base-url.com", "your-rest-resourse");RESTSchemaRetry uses the RestSharp library to execute the web requests.
The library is available on NuGet packetmanager. https://www.nuget.org/packages/RESTSchemaRetry/
RESTSchemaRetry uses the RestSharp library, which is distributed under Apache 2.0 license.
Thank you for considering to help out with the source code! If you'd like to contribute, please fork, fix, commit and send a pull request for the maintainers to review and merge into the main code base.
- Setting up Git
- Fork the repository
- Open an issue if you encounter a bug or have a suggestion for improvements/features
RESTSchemaRetry source code is available under MIT License, see license in the source.
Please contact at francesco.delre[at]protonmail.com for any details.