Hi, I'd just like some clarity and advice regarding running multiple cassandra instances on a single large machine (big JBOD array, plenty of CPU/RAM).
First, I am aware this was not Cassandra's original design, and doing this seems to unreasonably go against the "commodity hardware" intentions of Cassandra's design. In general it seems to be recommended against (at least as far as I've heard from @Rob Coli and others). However maybe this term "commodity" is changing... my hardware/ops team argues that due to cooling, power, and other datacenter costs, having slightly larger nodes (>=32G RAM, >=24 CPU, >=8 disks JBOD) is actually a better price point. Now, I am not a hardware guy, so if this is not actually true I'd love to hear why, otherwise I pretty much need to take them at their word. Now, Cassandra features seemed to have improved such that JBOD works fairly well, but especially with memory/GC this seems to be reaching its limit. One Cassandra instance can only scale up so much. So my question is: suppose I take a 12 disk JBOD and run 2 Cassandra nodes (each with 5 data disks, 1 commit log disk) and either give each its own container & IP or change the listen ports. Will this work? What are the risks? Will/should Cassandra support this better in the future?
