[e2e] Limit on simultaneous connections to a HTTP server

[Spencer Dawkins]

HTTP/1.0 didn't know what TCP was, to put it kindly. The spec
was written covering a single connection, not a set of
connections.

BTW - I've seen HTTP optimizers that rewrite HTTP responses as
"connection: close" for HTML, which forces some browsers onto
the more-than-two-connections path they use for non-persistent
connections, but then the four connections are allowed to be
"connection: persistent", doubling your fun. But this is the
kind of thing the HTTP spec doesn't cover.

Non-persistent connections is an optimization problem - how many
simultaneous connections do I need, to keep things moving, given
that so many objects are small (so single-threading GETs of
300-byte .gifs turns into a stop-and-wait protocol).

I remember that browsers used to allow the user to pick a
number, but 4 simultaneous non-persistent connections has become
quite common. Increasing this number helps for high-latency
connections (GPRS, etc), but there's really not a maximum number
in the spec, and really not a one-size-fits-all number.

Does this help?

Spencer

--- Srikanth Kandula <kandula at cs.uiuc.edu> wrote:
> 
> Hi,
> 
> Is there a limit on the number of non-persistent (HTTP/1.0)
> connections
> that an HTTP client simultaneously opens with a web server?
> 
> The HTTP/1.1 RFC constrains a client to atmost two
> simultaneous
> persistent connections.
> 
> -Srikanth
>