title: Which HTTP status code means "Not Ready Yet, Try Again Later"?
body: <p>I'm developing a RESTful API in which <code>http://server/thingyapi/thingyblob/1234</code> returns the file (aka &quot;blob&quot;) associated with item #1234 to download. But the request could be made before the file has been generated. It definitely <strong>will</strong> be available at a later time.</p>
  <p>There's a batch process in the server that generates all the blobs. Item 1234 already exists and its data, other than the blob, is already available. The server just hasn't generated 1234's blob yet.</p>
  <p>I don't want to return 404; that's for things that do not exist. This will exist, but hasn't been generated yet. Kinda like a YouTube video that's &quot;processing.&quot; I don't think redirection codes would be proper either; there's no &quot;other&quot; URL to try.</p>
  <p>What's the correct HTTP status code to return in such a case?</p>