Obsolete:TheBetterPathToLiveMigration
Contents
The Better Path To Live Migration
Rationale
The current code path for resizing and live migration is what you could call hairy in that the state-machine that is used to accomplish these 2 types of tasks (which are by there very nature extremely similar) is itself complex and could benefit from rework around a more organized state-machine which would be orchestrated by an external entity, of which said external entity can handle the intricacies of cross-compute communication as well as state-machine transitions and associated failure scenarios.
Definitions
- Live migration
- Moving a instance (and associated) resources from one compute node to another compute node while the instance is still running.
- Resizing
- Moving a instance (and associated) resources from one compute node to another compute node which can support the instance with re-sized capabilities (more/less VCPU for example)