Streaming Data

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.

Answer 2

When you say streaming data I think of the following, although I'm not sure if this is what you're getting at. To me it's playing a video/audio file while it's downloading. That's what happens when you go to YouTube and watch a video and it starts playing even though you haven't downloaded the whole video yet. But you can see the video downloading - I'm sure you're familiar with the seek bar filling up as the file downloads. It doesn't necessarily have to be a video or audio file but that's the most common.