Global scheduler

[dcvan24]

The scheduler in PIVOT now performs per-appliance scheduling, which maximizes utility for every single appliance. This is more like a greedy approach and could contradict with the global objective, causing suboptimal resource allocation and harming per-appliance scheduling in long term.

Hence, it calls for a global scheduler that optimizes resource allocation globally to balance between per-appliance and global objectives. Specifically, it is expected that the global scheduler is able to migrate containers as appliances/containers are created and terminated.

[dcvan24]

Now the global scheduler framework is working, although it runs no scheduling algorithm at all at this moment.