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Re: "Binary XML" proposals
- From: "Al B. Snell" <firstname.lastname@example.org>
- To: Vassilis Papadimos <email@example.com>
- Date: Fri, 13 Apr 2001 00:57:28 +0100 (BST)
On Thu, 12 Apr 2001, Vassilis Papadimos wrote:
> > Three-way handshake before you even send the request, the
> > connection teardown? *retch*!
> The three-way handshake is part of any TCP-based protocol, right?
> Plus, with HTTP versions > 1.1, you can amortize the connection
> overhead over multiple connections.
Mmmm, but who implements this in practice? Some Web clients are starting
to, but which SOAP clients/servers?
And there are big problems with that model, too. You can't do asynch
RPCs. You do send, wait, reply, send, wait, reply. You need to start
opening more connections if you want to issue parallel requests.
> Are there any reasonable alternatives?
Sure; UDP. Look at existing RPC protocols and learn from them.
ONC RPC allows UDP and TCP transports.
The UDP one has a maximum message size, 64k, and doesn't guarantee
delivery (so you have to retransmit manually; I wish it'd automate it!)
The TCP one is good if you expect a long conversation, and don't mind the
conversation being synchronous.
Eg, the RPC protocol for NIS (aka YP) recommends that you use UDP for just
asking simple questions of the NIS database (it works like LDAP or DNS as
a first approximation), but if you're a backup server wishing to take a
database replica, consider opening a TCP connection and using that.
Read RFCs - http://RFC.net/rfc998.html would be nice if it was widely
Alaric B. Snell
http://www.alaric-snell.com/ http://RFC.net/ http://www.warhead.org.uk/
Any sufficiently advanced technology can be emulated in software