Re: open transport protocol for aysnc web services?

Hi Mark,

Mark Nottingham wrote:
> 
> So this is something I couldn't determine about KN and related
> solutions, and didn't get into talks deep enough to get a solid
> answer;

When they launched a couple of weeks ago, they put up their
documentation at developer.knownow.com.  Check it out.

> Do they do polling from the client, or send asynch messages from the
> server to the client?

If by "they", you mean does any of their client side stacks do it, then
the answer is, no, they don't poll, and yes, they do send asynch
messages. Nothing prevents you from writing software that polls their
router though, if you want to do that.

They also use a persistent HTTP 1.1 GET connection to implement
subscription semantics.  The router responds with the event
notifications on the response stream of the GET, so long as the
connection is up.

> If they do polling, it's ugly, and they have built-in latency, as
> well as infrastructure concerns, but it works.
> 
> If they do asynch server->client messaging, they fundamentally break
> the HTTP, and will not work when HTTP proxies, etc. are interposed.

I wouldn't say that they're breaking anything.  As their message
exchange pattern is asynchronous, it matters not that the "request" and
"response" streams don't necessarily traverse the same proxy.

MB

Received on Monday, 9 July 2001 15:06:30 UTC