Concurrent execution of scheduled tasks in Java

Question

I have a TimerTask that is designed to gather metrics at a specific interval. However it is possible that the period of the task execution is less than the time of task execution (occasionally if something times out and gets delayed).

Is there a way to execute multiple TimerTasks or Runnables, threads, etc. concurrently without waiting for the previous task to complete?

I know that Timer uses a single thread, and the ScheduledThreadPoolExecutor will delay execution regardless of the rate.

Thanks.

Answer 1

I would recommend you using Executors.newCachedThreadPool() or newCachedThreadPool(ThreadFactory threadFactory) with your own thread factory, in conjuction with Timer. So the code should look like this

Executor executor = Executors.newCachedThreadPool();
Timer time = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {

    public void run() {
        executor.execute(new Runnable() {

             public void run() {
                  //your business logic
             }
        });
    }
}, delay, period);

This way you would schedule tasks with some period and they would all run concurrently.

Answer 2

Use any Timer implementation, including ScheduledThreadPoolExecutor, but let your timer task do not execute your business logic, but instead quickly start another task (to a cached thread pool, or on its own newly created thread) which actually does heavy computations.