Re: PRIORITY extension

On 2014–07–14, at 9:10 AM, Greg Wilkins <gregw@intalio.com> wrote:

> 
> I don't really understand why the flow control mechanism is not sufficient to implement priority?
> 
> My understanding of the use-case for priority is when a client received many push promises and/or makes make parallel requests, then it can stipulate which ones it wants to receive first.  Why can't it use flow control windows to achieve this?

Because, it’s a mess when the client treats the server as a slave. If the flow control window is throttled below the server’s minimum threshold, you get deadlock. There are no negative window updates, so throttling down requires draining the existing window, which is otherwise likely to be arbitrarily high.

TCP implementations jump through many hoops to work reliably. You might as well use multi-connection.

Prioritization is high-level. Flow control is low level. Throttling is a horrible violation of separation of concerns.

Received on Monday, 14 July 2014 01:26:01 UTC