Inter-Process Synchronization with Barrier

Question

I have a program in Java that performs some computation in parallel. I can either run it on a single machine or using multiple different machines.

When executing on a single machine, thread synchronization is successfully achieved by using CyclicBarrier class from java.util.concurrent.CyclicBarrier package. The idea is that all the threads must wait for the other threads to arrive at the same point before proceeding with the computation.

When executing on multiple different machines, inter process communication is implemented via RMI (Remote Method Invocation). I have the same problem on this situation and I want the threads of these processes to wait for the others to arrive at the same point before continuing. I cannot use a shared CyclicBarrier object between the different processes because this class is not serializable.

What are my alternatives to get this barrier behavior on threads executing on different processes on multiple machines?

Thanks

You could setup an environment in which this operation looks less complex. I.e., here is a sample implementation for Hazelcast which uses distributed AtomicNumber to count arrived parties. — Andrey Chaschev
Even if it was serializable it still wouldn't be shared. Serializing it creates a fresh copy at the target, not a shared object. — user207421

Peter Lawrey Peter Lawrey · Accepted Answer · 2013-11-29T00:42:26

You don't need to pass a CyclicBarrier between processes. You can do an RMI call which in turn uses a CyclicBarrier. I suggest you look at HazelCast at it support distributed Lock and many other collections.

IMHO I would reconsider whether you really need all the processes to check point and find a way to avoid needing this in the first place.

Inter-Process Synchronization with Barrier

1 Answers