Scheduling VMs to servers taking into account the health of the platform.

This blueprint is about paying attention to the health of the server and taking that into account at various layers in OpenStack, such as when the scheduler selects a server as a target for running a VM. Servers may be in various states of disrepair such as permanent subsystem failure (fan failure), temporarily degraded (too hot)etc. For example, if a server has a voltage-sensor or thermal-sensor anomaly, it is probably not the best target for more workloads until the problem can be assessed. Similarly, if a server has suffered a HDD failure and is consequently performing a RAID rebuild, its available IOPs for production workload may be degraded for a few hours until it gets back into a healthy state. This blueprint is about creating a general framework to model these states, detect these conditions, account for these conditions in a systematic way, and to expose it to upper level SW such as the scheduler.