title: How to timestamp a response consistently with an associated request?
body: <p>I'm implementing instant search. Since a network doesn't preserve the order of the requests in the order of the responses, I wouldn't want a(n earlier) search for "francis" to overwrite a (later) search for "francis haart". </p>
  
  <p>I was thinking of a timestamping a custom http header in the request, then extracting it and weaving it back in the response. (I'm using ajax for the requests, and django for the responses.)</p>
  
  <p>What is the best practice for timestamping a response (e.g. the search results) consistently with the request (e.g. the search query)?</p>