You seem to know rather too much about this, so I Googled you :-) and found out you wrote EVS4J - Kudos!
I've always been slightly wary of the tight/intimate type of cluster that VS solutions end up giving. I'm more of a fan of the first part of your reply: If you replicate the messages in memory (to another machine or two) you do
not have to force to disk upon commit - you can thus take the disk out of the critical path. Therefore you can get great throughput even with short transactions and short messages.
Two server solutions usually seem more robust than 3+ server solutions; just my experience of the Real World. Usually people don't invest enough on the infrastructure to make N-way solutions fail deterministically (e.g. they skimp on network connections and multi-pathing). I am interested in how we could add VS to Qpid/Java though. Could you point us to a "Dummy's Guide" for this application of VS (obviously using EVS4J :-) We don't have the brainwidth to be expert in VS in addition to working with AMQP and Qpid. Many thanks for sharing your wisdom with us. John
