An event bus message consists of a body, options, and it can optionally expect a reply
- The event-bus allows passing any kind of data (JSON is the preferred payload format - As Vert.x is polyglot, JSON is ideal should verticles written in different languages need to communicate via message passing.)
- Parameter are passed through message headers
Incoming network data are being received from accepting threads then passed as events to the corresponding verticles.
When a verticle opens a network server and is deployed more than once, then the events are being distributed to the verticle instances in a round-robin fashion which is very useful for maximizing CPU usage with lots of concurrent networked requests.