Question

I have a number of asynchronous tasks to run in parallel. All the tasks can be divided into two types, lets call one – type A (that are time consuming) and everything else type B (faster and quick to execute ones).
with a single ScheduledThreadPoolExecutor with x poolsize, eventually at some point all threads are busy executing type A, as a resul type B gets blocked and delayed.
what im trying to accomplish is to run a type A tasks parallel to type B, and i want tasks in both the types to run parallel within their group for performance .

Would you think its prudent to have two instances of ScheduledThreadPoolExecutor for the type A and B exclusively with their own thread pools ? Do you see any issues with this approach?

Answer 1

No, that’s seems reasonable.
I am doing something similar i.e. I need to execute tasks in serial fashion depending on some id e.g. all the tasks which are for component with id=”1″ need to be executed serially to each another and in parallel to all other tasks which are for components with different ids.
so basically I need a separate queue of tasks for each different component, the tasks are pulled one after another from each specific queue.
In order to achieve that I use

Executors.newSingleThreadExecutor(new JobThreadFactory(componentId));

for each component.
Additionally I need ExecutorService for a different type of tasks which are not bound to componentIds, for that I create additional ExecutorService instance

Executors.newFixedThreadPool(DEFAULT_THREAD_POOL_SIZE, new JobThreadFactory());

This works fine for my case at least.
The only problem I can think of if there is a need of ordered execution of the tasks i.e.
task2 NEEDS to be executed after task1 and so on… But I doubt this the case here …