I am writing a new release of my Spring CQRS Module(link1, link2), including a parallel execution feature. Concurrency issues can be hard to solve especially with new programming language features.
The issue with Java 8 promises
However, I am encountering several issues with the Java 8 promises aka CompletableFutures.
My issues are :
- I am using a dedicated ForkNodePool but some promises are stilled created outside my pool
- Some threads are slow to die (WAITING state is too long)
- Completable.allOf is creating promises in the common ForkNodePool
- I had an exceeded waiting for thread exception
Here are two links that are helping me a lot to solve these problems :
These two articles are well documented and explain in detail how Java/Threads/Java/JVM/Promises and parallel streams work.