title: Which HTTP errors should never trigger an automatic retry?
body: <p>I'm trying to make a few microservices more resilient and retrying certain types of HTTP requests would help with that.</p>
  
  <p>Retrying timeouts will give clients a terribly slow experience, so I don't intend to retry in this case. Retrying 400s doesn't help because a bad request will remain a bad request a few milliseconds later. </p>
  
  <p>I imagine there are other reasons to not retry a few other types of errors, but which errors and why?</p>