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Re: Multiple Open of the XMLHttpRequest object

From: Jim Ley <jim@jibbering.com>
Date: Sat, 28 Oct 2006 12:58:59 +0100
Message-ID: <003801c6fa88$74902da0$2101a8c0@Sniff>
To: "Denis Sureau" <dgsureau@yahoo.com>, <public-webapi@w3.org>

"Denis Sureau" <dgsureau@yahoo.com>
> "You can't have multiple requests at the same time
> with a single XMLHttpRequest object."
>
> I am speaking of multiple open calls, with multiple instances of the
> XHR object.
>
> Eventually we can check what is returned by onReadyStateChange to move
> a step forward, with the right object.
>
> If agree that we have to resolve the issue before to make a specification.

The underlying limits should be decided by the browser, and it should queue 
up other open requests - for example with persistent connections:

http://www.w3.org/Protocols/rfc2616/rfc2616-sec8.html

says "A single-user client SHOULD NOT maintain more than 2 connections with 
any server or proxy", now many user agents today decide to ignore the SHOULD 
NOT and pick a limit of 4 or more (this may be appropriate, it may not be)

I don't believe we can limit it to only 1, that would be silly - and we 
can't require more than 2, as that would be incompatible with RFC2616, yet 
limiting it to 2 seems unreasonably restrictive.

For that reason I do not see any sensible way we can require or limit the 
number, and it should be down to the user agents to maintain.

We should probably note the RFC 2616 limit of 2 (as IE does enforce this 
limit, so it is a hard practical limit)

Cheers,

Jim. 
Received on Saturday, 28 October 2006 11:59:30 GMT

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