----- Original Message -----
From: "Brian Behlendorf" <brian@collab.net>
To: "cap" <cap@mail.novosoft.ru>
Cc: <dev@subversion.tigris.org>
Sent: Saturday, November 04, 2000 00:57
Subject: Re: bxxp and subversion
> On Fri, 3 Nov 2000, cap wrote:
> > I have read documentation on the project.
> >
> > It looks like BXXP protocol could lay a good foundation for network
layer
> > for subversion. There is an apache module for BXXP and java and python
> > clients.
> >
> > Please look at http://www.bxxp.org/bxxp/.
>
> We've selected the DAV protocol; what would bxxp provide that DAV
doesn't?
> Don't just tell me why bxxp is or may be cool, please only mention things
> that we won't be able to do with DAV.
>
> Brian
>
I have less understanding of DAV then BXXP so comparation with DAV could be
incorrect. BXXP is not protocol. It is protocol framework that allow
quickly
create protocol like one needed for subversion.
BXXP is more like HTTP 1.1 layer then DAV layer. It could be possible to
combine two layers, i.e. to replace HTTP 1.1 to BXXP in DAV protocol. This
will require some technical changes in DAV as I understand it. As I
understand you will not follow DAV on some items like locking anyway.
BXXP have following features that could be useful for :
1. Good subconnection management
--------
For example if reading one file from disk is failed in the middle, server
can intrupt just one file and still keep phisical connection and its state
active, so there will be no need to reconnect. As I remember HTTP 1.1 have
very poor error recovery.
--------
2. Channel security (I do not know what DAV say here)
----------
BXXP provide standard configurarion for encripted chanels. Encription is
option in BXXP so protocol need not be rewrited for encription. One of
unplesant tasks with SSL were to detect that incomming connection is
encripted.
---------
3. Authentication
-------
Both support it.
------
4. Ansynchronous messaging over single TCP channel
--------
It will allow client to receive messages while doing commit and chekout. It
will also allow server to ask client something in the middel of operation
and then continue primary operation.
This feature will allow to make queue of requests. For example while
reading
one file you may decide the you want to download other file that was not on
initial list of files. In BXXP based protocol you will just need to post
message during file download. It will not even require seprate connection.
This could be useful for metadata repositories that are stored using
subversion. They are often navigated from root file to linked files.
----------
Simple Intro: http://www.bxxp.org/bxxp/info/bxxp30k.jsp
FAQ: http://www.bxxp.org/bxxp/info/qanda.jsp
BXXP is not just a protocol, on http://www.bxxp.org there are links to
libraries that support bxxp inluding apache and Java, so writing network
layer should be easy. I do not know situation wil open source libraies
related to DAV.
Have I answered you question?
Constantine
Received on Sat Oct 21 14:36:14 2006