Question 1

Heimdall vs resty: which Go HTTP client is better for retries?

Accepted Answer

Heimdall provides built-in retry and circuit breaking features out of the box, focusing on fault tolerance, while resty offers more general-purpose middleware but requires manual setup for advanced resilience. Choose Heimdall for applications where resilience is a primary concern, but resty might be more flexible for other use cases.

Question 2

How to add custom authentication headers with Heimdall?

Accepted Answer

Implement a custom HTTP client by creating a struct with a Do method that sets headers, then use the WithHTTPClient option when initializing the client. The README includes an example with basic authentication that demonstrates this approach.

Question 3

Does Heimdall support context in Go for request cancellation?

Accepted Answer

Heimdall is compatible with the standard http.Client, so you can use context with requests via the *http.Request object. However, the retry and circuit breaking logic may not fully integrate context cancellation, so it's important to test for edge cases in time-sensitive scenarios.

Question 4

What are the performance implications of using Heimdall?

Accepted Answer

Heimdall adds overhead for retry logic and circuit breaking checks, which is minimal for typical use cases but can become significant in high-throughput environments with many concurrent requests and retries, due to its synchronous in-memory design.

Question 5

How to configure exponential backoff in Heimdall?

Accepted Answer

Use the NewExponentialBackoff function with parameters like initial timeout, max timeout, exponent factor, and jitter interval, then create a retrier and client with it. The README provides a code snippet showing this configuration step-by-step.

Question 6

Can Heimdall be used with Go frameworks like Gin or Echo?

Accepted Answer

Yes, Heimdall can be used as the HTTP client for making external requests from within Gin or Echo handlers, as it's library-agnostic and follows standard Go interfaces. Just instantiate the client in your code and call it as needed.

heimdall

What is heimdall?

Overview

Use Cases

Best For

Related Projects

Found a gem we're missing?

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions