[jax-rs-spec users] [jsr339-experts] Re: How are suspended responses usually managed?

From: Bill Burke <>
Date: Sat, 13 Oct 2012 06:36:32 -0400

On 10/12/2012 4:39 PM, Markus KARG wrote:
> Yes this is one form of COMET. And: No, typically the browser will not keep
> the connection open, since this only works if a really lot of constraints
> *all* are fulfilled:
> - The browser, the server, and all intermediate proxies must be http/1.1
> compliant AND implement the persistent connection feature (which is optional
> even in http/1.1), and all these systems must be bug-free.
> - The browser, the server, and all intermediate proxies must intend to
> actually use the persistent connection feature, as even a http/1.1 compliant
> party that fulfils the above constraints in some situations might
> intentionally prefer not to keep the connection open but instead close it
> temporarily and restart another connection later (e. g. if the traffic on
> the party is rather high, but the traffic on that push line is rather low),
> which is a valid implementation of http, unless http/1.0 will be officially
> "forbidden" (which typically will never happen).
> - All of the participating parties must do both above issues at the same
> time. If only one constraint is not fulfilled at any time, the connection
> cannot kept open.
> Example: You did your best efforts but for offloading reasons a Squid 3
> proxy is installed -- which does not implement http/1.1 completely and
> chances are high that it has lots of bugs... which foils the browser's and
> server's best efforts.
> You see, chances are very low that the connection actually is left open
> (unfortunately).

Sounds like you have a *lot* more experience than me with this, but, I
still find it hard to believe that the connection is closed so often. If
this is true, then COMET style apps really aren't much more performing
than vanilla HTTP.

Bill Burke
JBoss, a division of Red Hat