Google Finance Comet

by Martin TylerJune 4th, 2008

Google finance now has real-time stock quotes from Nasdaq.

Real-time Quotes

Previously all free stock quotes on the internet were 15 minute delayed - so even if they were being streamed, which might give a better user experience, they weren’t much good for anything serious.

I have taken a look under the covers and, when using Firefox at least, it is using a streaming transport using chunked encoding. The contents itself are JSON.

A typical chunk looks like this:

166
[[16,[{"s":"NASD:MSFT","l":"27.88","c":"-0.44","cp":"-1.55","ltt":"11:40AM ET"}]]
,[17,[{"s":"NASD:EBAY","l":"29.15","c":"-0.86","cp":"-2.87","ltt":"11:40AM ET"}]]
]

The subscriptions are part of a separate request, which indicates you could change subscriptions. In other words it would support an interactive GUI unlike some very simple streaming solutions based on a single request.

Since this is Google, you would imagine that this scales well, and they can obviously throw lots of hardware at the problem too if necessary.

Does anyone know any more about this technology?

Comments are closed.


Copyright 2015 Comet Daily, LLC. All Rights Reserved