how to perform periodic checks in java without using Thread.sleep?

Question

I have a program (thread) which starts a task on a remote machine on the cloud. I want to monitor the progress of this task and if it exceeds a specific timeout T, then it will be cancelled and more cloud resources will be added and the task will start again.

How can I monitor the thread which is executing this task?

Example Scenarios:

1. Timout = 1 hour, the task is finished in 40 mins, hence everything should terminate normally.

2. Timout = 1 hour, the task has failed after 55 mins due to lack of resources, hence more resources added and the task is started again

3. Timout = 1 hour, the task did not finish after 1 hour, hence its killed and more resources added then the task is started again.

So how can I implement that timely monitoring in java?

Answer 1

您正在寻找ScheduledThreadPoolExecutor类，正是该类。

Answer 2

You could submit the task to an ExecutorService, try to get the result with a timeout and if you have a timeout, cancel the task.

It could look like:

ExecutorService executor = Executors.newFixedThreadPool(1);
Future<?> future = executor.submit(yourTask);
try {
    future.get(1, TimeUnit.HOURS);
} catch (TimeoutException e) {
    future.cancel(true);
    resubmitWithMoreResources();
} catch (ExecutionException e) {
    Throwable underlyingCause = e.getCause();
    if (underlyingCause instanceof ResourceException) {
        resubmitWithMoreResources();
    } else {...}
}