- From: Martin Nilsson <nilsson@opera.com>
- Date: Sat, 09 Jun 2012 00:30:09 +0200
- To: "Mike Belshe" <mike@belshe.com>
- Cc: "Roberto Peon" <grmocg@gmail.com>, ietf-http-wg@w3.org
On Fri, 08 Jun 2012 21:10:59 +0200, Mike Belshe <mike@belshe.com> wrote: >>> >> I'm using the same data as the http://www.eecis.udel.edu/~** >> amer/PEL/poc/pdf/SPDY-Fan.pdf<http://www.eecis.udel.edu/~amer/PEL/poc/pdf/SPDY-Fan.pdf>and >> when using the evaluation set they use I actually get somewhat better >> compression values (probably due to better header normalization). > > > The point of SPDY header compression is to use stateful compression. If > you only compress one chunk of headers, you'll get modest savings - > 30-50%. > but on the second set, you get like 95% :-) For SPDY sessions in steady > state, the typical size of a request is 50-60 bytes. Almost everything, > including the cookies, compresses out. > Yes, that is quite clear from the specification, and I noted "deflate with persistent context is a good approach" in the original text. The context here is about using a deflate dictionary, and then the subsequent requests compress almost equally well without dictionary. This is natural given how LZ77 works and the repetitive nature of HTTP headers. So if you are only making single requests on every SPDY connection, the dictionary gives you a 15-25% boost on the header compression. If you are making multiple requests you will however very quickly see the benefit over normal deflate disappear. /Martin Nilsson -- Using Opera's revolutionary email client: http://www.opera.com/mail/
Received on Friday, 8 June 2012 22:30:33 UTC