Re: [Dynapi-Help] Simple communication questions...

[Leif W <war...@us...>]

This is going to be one of those revolutionary technologies that puts the
DynAPI over-the-top.  :)

Leif

----- Original Message ----- 
From: "Raymond Irving" <xw...@ya...>
To: <dyn...@li...>
Sent: Wednesday, October 15, 2003 4:14 PM
Subject: Re: [Dynapi-Help] Simple communication questions...


>
> In the DynAPI design sockets or http connections are
> not held or opened in definately. They're opened only
> for short periods of time (e.g. 50 secs) then released
> and reopened a few seconds later. This makes it
> posible to use both Push and Pull techniques to
> balance the connection load.
>
> The user (server-side) will have the option to adjust
> and balance the system while having the choice of
> using either push, pull or both.
>
> --
> Raymond Irving
>
> --- Leif W <war...@us...> wrote:
> > This looks very promising.  I've skimmed through the
> > whitepaper and a couple
> > example sources but can't seem to find exactly what
> > HTTP headers they're
> > sending, or if they're not doing the multipart hack
> > which is netscape and
> > mozilla specific, but instead just constantly
> > streaming code to an open
> > socket which appears to be what they're doing.
> >
> > Just wanted to point out what I think is the main
> > disadvantage of this
> > design, and reiterate and elaborate upon that point
> > just so it's understood
> > and maybe either find some way to work around, or at
> > least make sure we pass
> > on the warning to developers who may use our
> > library.  Using this technique
> > requires a socket to be constantly open between the
> > client and the server.
> > Normally, the browser makes a request, the socket is
> > used then released and
> > is free for the server to use to handle more
> > requests.  But with this
> > technique, the sockets will be used directly
> > proportional to the number of
> > users using the push, plus the number of users
> > otherwise requesting
> > documents on the server.  But most computers are
> > compiled with 65535 sockets
> > by default I believe.  I am not sure if any
> > operating systems allow for this
> > number to be increased.  I suspect that OSes like
> > Linux and FreeBSD would
> > allow this to be increased, by hacking the source
> > code.  It may or may not
> > be as trivial as changing a C language #define.
> > However it is done, having
> > achieved the proper modification and documented it,
> > recompiling the kernel
> > source is usually trivial for admin that keep their
> > software generally
> > unmodified and up to date, and who don't rely solely
> > on rpm or dselect to
> > handle everything, but it may not be trivial if they
> > have heavily modified
> > sources, dependent on third party code, or something
> > bizarre.  But be aware,
> > this may be in a shared hosting environment, or a
> > dedicated web server, may
> > be owned by the company that runs the hosting
> > provider, or by the company
> > that runs the web site.  The usage of this on a
> > moderate to high-traffic
> > site hosted on a machine that is currently handling
> > all it's requests with
> > plenty of socket overhead may hit a a resource
> > limitation which could affect
> > the whole server, which could be undesirable,
> > especially in a shared hosting
> > environment.  Also, there may be many levels of
> > management or ownership
> > between the web developer using this technique in
> > the DynAPI, and the admin
> > who would need to respond to the potential increased
> > resource requirements
> > if this technique were to be deployed on a
> > relatively high-traffic website.
> > Therefore I think it's imperative that we have some
> > sort of disclaimer on
> > the documentation page, and perhaps another page
> > with either notes to
> > increasing the number of sockets, or links to such
> > resources or something.
> >
> > Leif
> >
> > ----- Original Message ----- 
> > From: "Raymond Irving" <xw...@ya...>
> > To: <dyn...@li...>
> > Sent: Wednesday, October 15, 2003 11:34 AM
> > Subject: Re: [Dynapi-Help] Simple communication
> > questions...
> >
> >
> > >
> > > Wow!
> > >
> > > I've spend serveral hours looking into the
> > push/pull
> > > (pushlet) solution and must say that I have
> > managed to
> > > get a working prototype of the server-side push
> > > feature.
> > >
> > > I think it's possible that dynapi will be able to
> > > support both Push and/or Pull functionality. It's
> > > still a far way off and requires a lot of time to
> > > think through the design of the system (only if I
> > had
> > > a full time dynapi job :)
> > >
> > > In short I think it will be as simple as adding an
> > > event listener to a dynobject:
> > >
> > > io.addEventListener({
> > >    onserver_someventhere : function(e,s) {
> > >         // some code here
> > >    },
> > >    onserver_anothereventhere : function(e,s) {
> > >         // some code here
> > >    }
> > > });
> > >
> > > With this technology we could use ioelement with
> > any
> > > webserver or server-side language to implement the
> > > push and/or pull requests
> > >
> > > With the push method the client is notified
> > whenever
> > > the server invokes or raises an event:
> > >
> > > ws_invokeEvent('someeventhere')
> > > ...
> > > ws_invokeEvent('anothereventhere')
> > >
> > >
> > > The Push/Pull technique should work with all
> > supported
> > > web browsers. The API will handle all the
> > technical
> > > details so the user only have to listen in for an
> > > event from the server.
> > >
> > > What do you think?
> > >
> > >
> > > --
> > > Raymond Irving
> > >
> > >
> > >
> > > --- Andrew Gillett <an...@zo...> wrote:
> > > > This may be a little off-topic, but another
> > > > interesting site that's worth a look at is
> > > > www.pushlets.com.  Their basic setup is to use a
> > > > Java servlet to push javascript down a HTTP
> > > > connection to a hidden frame.  And they have
> > some
> > > > impressive demos :)  The claim compatability
> > with IE
> > > > (back to 4.01) and Netscape (back to 4.05).
> > > >
> > > > It would be _so impressive_ if an IOElement
> > could do
> > > > a similar thing....
> > > >
> > > >
> > > > Andrew Gillett
> > > >
> > > >
> > > > Raymond Irving wrote:
> > > > > Hi,
> > > > >
> > > > > For some more information on server-push and
> > > > > client-pull visit the following website:
> > > > >
> > > > >
> > > >
> > >
> >
> http://wp.netscape.com/assist/net_sites/pushpull.html
> > > > >
> > > > > --
> > > > > Raymond Irving
> > > > >
> > > > > --- Leif W <war...@us...> wrote:
> > > > >
> > > > >>I was thinking of how to approach this problem
> > a
> > > > >>while back (for the case of
> > > > >>a simple online cardgame) but never came to
> > > > anything
> > > > >>concrete.  However, I
> > > > >>did remember playing with some script (it was
> > in
> > > > >>Perl but you could use any
> > > > >>language) which acts as a server-push, but it
> > only
> > > > >>works for Mozilla, not
> > > > >>IE, and not tested in Opera or Safari.  So, if
> > you
> > > > >>want a true client-server
> > > > >>model with bidirectional communication I guess
> > > > >>you're best off coding a Java
> > > > >>applet for the browser, and whatever language
> > > > >>specialized server with your
> > > > >>own protocol.
> > > > >>
> > > > >>Anyways here's the example code I was using.
> > > > Also,
> >
> === message truncated ===
>
>
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