1. A computer-implemented method, comprising: determining, by a host controller machine, that one or more collected metrics have triggered a load balancing operation of the host controller machine, wherein the one or more collected metrics include memory-related metrics of one or more host machines managed by the host controller machine and of an overall system of the host controller machine; selecting, by the host controller machine, a host machine of the one or more host machines to migrate a virtual machine (VM) from as part of the load balancing operation, wherein the selecting the host machine includes consideration of the memory-related metrics of the host machine; and selecting, by the host controller machine, a VM of a plurality of VMs hosted by the selected host machine to load balance migrate from the selected host machine, wherein the selecting the VM includes consideration of memory-related metrics of the VM.