CODEWITHSUNDEEP
javasynchronizationjvmcluster-computingdistributed
maverick
maverick

Reputation: 589

Maintaining a single instance over multiple JVM

I am creating a distributed service and i am looking at restricting a set of time consuming operations to a single thread of execution across all JVMs at any given time. (I will have to deal with 3 JVMs max).

My initial investigations point me towards java.util.concurrent.Executors , java.util.concurrent.Semaphore. Using singleton pattern and Executors or Semaphore does not guarantee me a single thread of execution across Multiple JVMs.

I am looking for a java core API (or at least a Pattern) that i can use to accomplish my task.

P.S: I have access to ActiveMQ within my existing project which i was planning to use in order to achieve single thread of execution across multiple JVM Machines only if i dont have another choice.

Upvotes: 0

Views: 2282

Answers (1)

Avi
Avi

Reputation: 351

There is no simple solution for this with a core java API. If the 3 JVMs have access to a shared file system you could use it to track state across JVMs.

So basically you do something like create a lock file when you start the expensive operation and delete it at the conclusion. And then have each JVM check for the existence of this lock file before starting the operation. However there are some issues with this approach like what if the JVM dies in the middle of the expensive operation and the file isn't deleted.

ZooKeeper is a nice solution for problems like this and any other cross process synchronization issue. Check it out if that is a possibility for you. I think it's a much more natural way to solve a problem like than a JMS queue.

Upvotes: 2

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