title: HTTP statuscode to retry same request
body: <p>Is there an HTTP status code to instruct a client to perform the same request again? </p>
  
  <p>I am facing a situation where the server has to "wait" for a lock to disappear when processing a request. But by the time the lock disappears, the requests might be close to its timeout limit. So instead, once the lock clears, I would like to instruct the client to just perform the same request again.</p>
  
  <p>The best I an come up with is a HTTP 307 to the same location, but I'm worried that some browsers might not buy into this (redirect loop detection).</p>