How to decide the optimal number of ruby thin/mongrel instances for a server, number of cores?
- by Amala
We are trying to deploy mongrel instances on a machine.  What is the optimal number of mongrel instances for a server?  Since an instance can handle concurrent connections, I do not see any benefit in starting more than 1 per core.  Any more than that and the threads will just fight for CPU.  Our predecessors have assigned 10 instances for 4 cores, but I think it will just cause CPU contention.  Any definitive answers / opinions?
I have seen this question: How many mongrel instances?
But it is really not specific enough.