- From: Patrick McManus <pmcmanus@mozilla.com>
- Date: Wed, 22 May 2013 15:32:05 -0400
- To: HTTP Working Group <ietf-http-wg@w3.org>
- Message-ID: <CAOdDvNpksxHi1z8tVNN9VZ1sQ0SA5mWgxOY001P48qtBGbDeFg@mail.gmail.com>
Hello, While reading the flow control text again there was some ambiguity in my mind about whether or not the SETTINGS_INITIAL_WINDOW_SIZE adjusted the connection window or just all current and future stream windows. I've decided the text is really going for "just stream windows - connection windows are only adjusted by WINDOW_UPDATE with stream=0" (an interpretation I favor).. I think it would be nice if it said that explicitly to clear up confusion. There are some PoC implementations of this floating around out on them thar Internets (admittedly they may predate the current spec language) and I've seen different interpretations of what is logical.. so it makes sense to be explicit. A couple related followup tweaks to the text: section 3.8.9.2 * * *"When a HTTP/2.0 connection is first established, new streams are created with an initial flow control window size of 65535 bytes. The connection flow control window is 65536 bytes. Both endpoints can adjust the initial window size for new streams by including a value for SETTINGS_INITIAL_WINDOW_SIZE in the SETTINGS frame that forms part of the connection header. *" I suggest s/in the SETTINGS frame that forms part of the connection header/with a SETTINGS frame/ .. The section is titled "Initial Flow Control Window Size" so the existing text could be ok if we mean initial to be at connection establishment time, but I think it more clearly applies to the life cycle of each stream (at least when talking about stream windows). ** ** ** *When the value of SETTINGS_INITIAL_WINDOW_SIZE changes, a receiver MUST adjust the size of all flow control windows that it maintains by the difference between the new value and the old value. * uh-Oh.. "all flow control windows that it maintains" definitely includes the connection window :( I suggest s/flow control windows/stream flow control windows/ -Patrick
Received on Wednesday, 22 May 2013 19:32:36 UTC