Question

I’m very interested in how financial data is streamed from server to client. I often here the term ‘push-pull’ used. I wondered if someone could give me an example (preferably in Java, C# or perhaps Javascript) how this is actually achieved? Whenever I have written amateur hobby projects at home I often end up querying a URL (containing the price) and continuously calling this within a while(true) loop, with a thread.sleep(x), even if the price doesnt change.

Thanks in advance

Answer 1

Don’t know what you mean with ‘streaming financial data’, but the concept of push/pull is not limited to the financial sector 🙂

Generally speaking, pull strategy means that the client is actively getting data through a pre-defined communication channel (in your case a socket to an existing and known URL) and polling this channel for new information.

In contrast to that you have the push strategy where you are notified of any changes and you supply the communication channel and register it with the connection’s partner. E.g. you have a webservice and your connection partner will post information to that webservice whenever he sees fit. See http://en.wikipedia.org/wiki/Observer_pattern for this concept.

Hope this helps a bit.