In HybridCluster we did I/O based load balancing. IOW, the primary metric used to decide when to juggle a container onto a less loaded machine was the aggregate

In HybridCluster we did I/O based load balancing. IOW, the primary metric used to decide when to juggle a container onto a less loaded machine was the aggregate disk busy % on the ZFS pool. This kept disk-bound workloads nice and fast in general - if a database starts hammering the disk, the system will automatically "make room" for it, by moving some other busy containers on that machine off to quieter machines. We'd likely do something similar - eventually - with Flocker. :)