[whatwg] XMLHttpRequest connection limit

Ted Goddard ted.goddard at icesoft.com
Wed Nov 1 08:34:24 PST 2006

Ajax applications often make use of multiple concurrent
HTTP requests; in particular Ajax Push (Comet/Reverse Ajax)
makes use of two HTTP connections: one to block waiting for
messages from the server, the other to send messages to
the server.

The problem is that the connection limit for many browsers
is two connections per browser per server. Sophisticated
Ajax applications, on the other hand, need two connections
per window (or tab) per server. This allows each window or
tab to support two-way messaging with the server.  Without
it (and without the ability for the two client windows
to communicate and thereby share a single connection) the
two available HTTP connections become consumed by the
blocking message requests.

I would like to propose that the HTTP connection limit
be standardized at two per user-initiated window. (For
instance, Safari is not limited to two connections per
browser.)  This should be a relatively straightforward
change in browser policy (browsers other than Safari,
that is), but it is a significant enhancement for
Ajax applications.


Ted Goddard, Ph.D. - Senior Software Architect
ICEsoft Technologies Inc
Suite 300, 1717 10th St. NW
Calgary, AB - Canada - T2M 4S2
T 403 663-3322
F 403 663-3320
ted.goddard at icesoft.com

More information about the whatwg mailing list