Event Listener with C++

Dear Infinispan community,

as announced in a previous post, starting from version 8.1.0 also the C++/C# clients can receive and process Infinispan events.

Here’s an example of usage of C++ event listeners that, with a good dose of imagination, pretends to be a customer behavior tracking system for our store chain (don’t take this too seriously, we’re just trying to add some fiction).

As a first requirement our tracking system will record every single purchase made in our stores. How many stores we have? 1, 100, millions? It doesn’t matter: we’re backed with an Infinispan data grid. This is version 0.x and hence the checker must use the keyboard to enter all the needed information.

As you can see our entry key is a concatenation of the product name and the timestamp and the entry value is an unstructured string, maybe too simply but it could work for now. Seems we are at a good point: we have the data and we can do analytics on it, so far so good but now our boss makes a new request: he wants a runtime monitor on how’s the sales performance. That’s a perfect request to be fulfilled with event listener: the monitor application will be an Hotrod C++ client that registers a client listener on the server and receives and show on the boss’s laptop the data flow. A client listener, once registered on the server, can receive events related to: creation, modification, deletion, expiration of cache entries; in our example only the creation and expiration events are processed (expired events can be useful to do some moving average statistics?). Following a snip of code that creates and registers a listener that writes the events key on the stdout.

You can git this quickstart here [1]. On startup a multiple choice menu is shown with all the available operations. Running several instances you can act as the checker (data entry) or the boss (installing the listener and seeing the events flow).