Vertx
Compile & execute:
mvn clean install
java -jar target/[substitute_with_name]-fat.jar -cluster
Standard vs Worker Verticle
Concurrency is handled completely by Vert.x
When created, a standard verticle will have one Event-loop assigned to it (it’ll always use the same) and the start method it’s called within that Event-loop.
If it calls other Handlers, it can guarantee that they’ll be executed in the same Event-Loop
Meanwhile, a worker verticle will have a different Thread assigned to it, everytime it wants to perform a Job.
If you’re able to use a standard verticle for non-blocking jobs, you’ll save resources every time you execute code with it.
A standard verticle runs in an Event-Loop thread (one of many). If they’re completely blocked, the whole Program will be blocked and it will just halt. On the other side, the worker verticles run on a different Thread than the main event-loop, so they’re perfect to execute blocking code (another option is an inline .executeBlocking() call). They will never be executed by more than one Thread simultaneously, but they may be executed each time by different Threads.
The downside of using always workers, is that the max. concurrency achievable is much lesser than using normal verticles + workers. With a lot of blocking tasks, you may create a processing queue.