While I agree with some of this like not letting people go run amuck and write bad code just because they think clustering can be done transparently I did have one small issue. The thing about your choice of example of CyclicBarrier is that I find it to be one of the most useful things to cluster. When we wrote a distributed testing framework we clustered the meta-data for the tests and coordinated the starts and stops using a clustered CyclicBarrier. Thinking back to all the times I had to coordinate processes before using Terracotta and all the hoops I jumped through makes me really love the terracotta model of dev. Cheers, Steve (I work at terracotta)