[whatwg] General TCP connections API?
kornel at ldreams.net
Thu May 26 12:58:35 PDT 2005
> The client is polling the server. And often a new TCP
> connection is created (and later tore down) each time the server is
> polled. (Which, IMO, is bad.)
HTTP/1.1 uses persistent connections by default. If you set long keepalive
time on your webserver, chances are that all requests are going to be done
over same TCP/IP connection.
To have your own connections you'd have to use other port than 80 and that
may be disallowed on many restricted systems.
If user navigates to the next page, browser will destroy your JS objects
and close their connections. That may result in worse performance than
with HTTP connection that is kept alive between pages.
Even if connections are limited to the same host, you couldn't safely
serve anything else on it. Spammers might use numerous HTML-injection
techniques to send spam using other people's computers, and this may get
much worse if host restriction fails. From past experience of hundreds of
cross-site scripting vulnerabilities, you can be sure that this will
happen sooner or later.
BTW: There's a hack that lets you get data from server without polling -
use iframe, start sending its contents and don't close connection - keep
sending <script> elements one by one.
pozdrawiam, Kornel Lesinski
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