title: What status code should I return for a connection error?
body: <p>I'm writing a service that returns data about another request to the consumer (for example, retrieving the un-shortened URL from a bitly or t.co address). In most situations, I can return a status code to mirror the code I received from the server, but what status code is most appropriate when my service is unable to connect to the requested URL (if it doesn't exist, for example)? I was thinking <code>400 Bad Request</code> or <code>408 Request Timeout</code>, but is there a best practice here?</p>