RE: Fwd: I-D Action:draft-nottingham-http-pipeline-00.txt

Hi Willy,

To me, hinting is the most important part.  You need to know that a) the server and intermediaries that you are traversing wont break, and b) that there are no other problems with specific resources, like potential head-of-line blocking.

As for the request ID, I think that Mark's succinct description works best:

"
For example, if client A makes a request to a proxy cache with:
  Req-ID: abc
and the proxy goes to the origin server and gets a response with:
  Req-ID: abc
  Cache-Control: max-age=300
...and then client B makes a request to the proxy cache with:
  Req-ID: def
and gets the same response back from the cache (remembering that it hasn't been modified to support this), it'll get an error.
"

If you go to the trouble of fixing the proxy to support pipelining (again, most do), then all you really need is some indication that it's safe to proceed, not a per-request header.

The big challenge is with bad intermediaries and your plan seems to require that intermediaries change.  The bad ones wont.

--Martin