"Paul Querna" <[EMAIL PROTECTED]> wrote on 2008-9-21 4:21
Graham Leggett wrote:
I know there are likely huge problems with this, but I would like to see
how far
we can push the Event MPM, figure out what to do better, if there is
anything, and then really dive into the 3.0 development before
ApacheCon.
How difficult would this be to support in the other MPMs?
Windows, Worker MPM and the similar threaded MPMs could do it easily.
But, IMO, I want to eliminate all of the MPMs for 2.4/3.0.
I believe the MPMs as they are designed right now, are both a layer of
portability, and a module that defines behavior or the model.
...
Basically, one MPM to rule them all, with a configuration directive that
can make it act like prefork or the event MPMs.
Currently the role that MPMs play is to map a connection (with many
requests, by HTTP/1.1) to a worker (a thread or process). But an optimal
network i/o model needs a layer that maps a *request* to a thread, so that a
worker thread (or process) will not have to be tied up entirely with a
single connection during the whole life time of the connection. Instead, a
worker can be scheduled to handle different connections, which helps both
reducing the number of workers and the performance of request handling
(especially on slow connections).
Such a layer should unify the upper interface of Event driven i/o, Windows
i/o completion port, and many other async i/o mechanisms. With luck and
careful design, the current filtered i/o chain and the module API can remain
the same.
I hope that this would be one of the best features that 2.4+ will bring to
us, as finally it will support any optimal i/o model on various platforms,
and answer the doubts on Apache performance once and forever.
Bing
----
School of EE & CS,
Peking University,
Beijing 100871
