[LINK] WebSockets

[stephen at melbpc.org.au]

Perhaps of interest .. HTML5 'WebSockets'

To see how these new websockets work, have a look here:

 http://www.worldspreads.com/en/home.aspx

If your browser supports WebSockets, the world market information
at the bottom of the page will refresh every couple of seconds. For
example, as i write this, the Aussie dollar is worth 2.75 cents more
than the US dollar. Oops, now it's 2.81 .. and, now it's 2.83 cents :)

The new Mozilla browser supports HTML5 WebSockets, whereas IEv8 does not.

Here's a news article regarding WebSockets ..

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New Protocol Turbocharges the Web: WebSockets lets the Web handle complex 
communications in real time.

Monday, March 28, 2011 By Paul Boutin
<http://www.technologyreview.com/web/37162/?nlid=4279>

Over the past 15 years, Web-based applications have gradually replaced 
those based on other networking protocols for everything from personal 
communications to home electricity meters. 

But there's a major shortcoming in the hypertext transfer protocol—HTTP—
the system used to communicate over the Web. HTTP was originally designed 
for serving up simple documents and files to Web browsers, not for 
complex, real-time interaction.

Under the original HTTP protocol, a client, such as a Web browser, must 
open a connection to a server, make a request, wait for a response, and 
then close the connection. 

If the client needs more data, it must open a new connection. It's like 
hanging up the phone and redialing after every sentence of conversations.

And if the server has new info for the client, it must wait until the 
client requests it rather than sending it over instantly. 

This redundancy chews up bandwidth. Worse, it makes it nearly impossible 
to keep a Web client stuffed with up-to-the-second information. In some 
situations, such as financial trading, those lost milliseconds can mean 
missed opportunities.

Web developers have been hacking around HTTP's limitations for years with 
programming techniques such as Comet, which delays closing an HTTP 
connection in order to transmit more data. But what they really want is a 
connection between client and server that stays open indefinitely and 
allows both parties to send data back and forth as needed.

The nearly-complete HTML5 standard for current and future Web software 
includes just such a solution, a new protocol called WebSockets. 

This protocol allows a Web client to create a connection, keep it open as 
long as it wants, and both send and receive data continuously.

Kaazing, a startup based in Mountain View, California, was a leading 
developer of the WebSockets standard. 

The company now sells a product that serves as a software gateway, 
allowing WebSocket connections between existing Web clients—browsers, 
phones, and desktop software—and the back-end systems to which they 
connect. CEO Jonas Jacobi, who spent eight years working on Java-based 
corporate software for Oracle, says WebSocket technology is promising not 
just because it's faster, but because it's cheaper. "It removes the need 
for a lot of middleware," he says. "That's not where companies want to be 
putting their engineering resources; they want to focus on improving the 
product they deliver."

So far, Kaazing's early customers tend to be in the financial sector, 
where milliseconds count in transactions at banks, hedge funds, 
exchanges, and private trading firms. 

The company has partnered with Informatica, a maker of messaging 
software, to develop a WebSocket-based internal communications system for 
companies. 

Mike Pickett, a vice president at Informatica, says the appeal of 
WebSocket tech is that "it is agnostic to the specific type of [Web] 
browser—IE, Firefox, Chrome. Developers don't have to write a specific 
extension for each browser," which they often do for workaround 
solutions. (Currently, Internet Explorer requires an add-on to handle 
WebSockets.) Chrome, Firefox, Opera, and some other browsers have support 
built-in. If your browser supports WebSockets, you can watch a demo of 
financial markets updating several times a second at the bottom of this 
page. <http://www.worldspreads.com/en/home.aspx>

Kaazing's other early customers tend to be online gambling companies like 
Unibet. That's because betting requires up-to-the-second odds, which are 
hard to provide without a persistent connection. 

Importantly, WebSockets aren't exclusive to Kaazing.  Google has been an 
early champion. Besides building the technology into its Chrome browser, 
the company supports a site that shows developers how to implement it. 

 <http://www.html5rocks.com/tutorials/websockets/basics>

Ian Hickson, who leads HTML5 specifications for Google, wrote, "Reducing 
kilobytes of data to 2 bytes [...] and reducing latency from 150 
milliseconds to 50 milliseconds is far more than marginal. In fact, these 
two factors alone are enough to make WebSockets seriously interesting to 
Google."

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Cheers,
Stephen