Question

I unsuccessfully searched Google for a good definition and understanding of streaming data and its characteristics. My questions are:

1. What is streaming data?
2. How can it be detected?

Correction:

‘How can it be detected’ is not an appropriate question. Instead my question is:

How is it different from buffered data and other data transfer mechanisms?

Answer 1

It depends in what context you mean but basically streaming data is analagous to asynchronous data. Take the Web as an example. The Web (or HTTP specifically) is (basically) a request-response mechanism in that a client makes a request and receives a response (typically a Web page of some kind).

HTTP doesn’t natively support the ability for servers to push content to clients. There are a number of ways this can be faked, including:

• Polling: forcing the client to make repeated requests, typically inconspicuously (as far as the client is concerned);
• Long-lived connections: this is where the client makes a normal HTTP request but instead of returning immediately the server hangs on to the request until there’s something to send back. When the request times out or a response is sent th eclient sends another request. In this way you can fake server push;
• Plug-ins: Java applets, Flash, Silverlight and others can be used to achieve this.

Anything where the server effectively sends data to the client (rather than the client asking for it)–regardless of the mechanism and whether or not the client is polling for that data–can be characterised as streaming data.

With non-HTTP transports (eg vanilla TCP) server push is typically easier (but can still run afoul of firewalls and th elike). An example of this might be a sharetrading application that receives market information from a provider. That’s streaming data.

How do you detect it? Bit of a vague question. I’m not really sure what you’re getting at.