The Abiquo HA Process
1. After a physical machine is added to Abiquo:
- its reference is inserted to MySQL, which will keep the information we see on the GUI
- A subscription to the Physical Machine is created on the Virtual Subscription Manager or VSM. Any changes occurring to that Physical machine will be tracked by this Remote Service.
2. The physical machine is on a HA active rack and has IPMI configuration:
- Every X seconds (configurable in abiquo.properties), the Infrastructure Check checks all the physical machines (PMs). If a PM doesn't pass the check, it is marked as "candidate for HA".
3. On the physical machines marked as "candidate for HA":
- The Infrastructure Check will do more Y more checks on these PMs, (configurable HA cycles set in Abiquo properties). If all checks fail, Abiquo starts the HA process for the PM.
4. The HA process is started:
- Disable the PM (disabled by HA) in the GUI to avoid any further actions by users on it
- Remove the VSM subscription for the PM
- Power off the PM through IPMI or managed rack API
- Start the HA move for Virtual Machines
5. The Virtual Machine HA process consists in:
- Following the allocation rules, search for PMs that can host the VM that are located in the same HA rack and have the same hypervisor
- Check if the enterprise has enough resources available to deploy the VMs again
(At this point, it is possible that not all the VMs can be moved to new hosts, depending on the aforementioned factors)
- If VMs can be redeployed:
- Remove the VSM subscription for the VM
- Do the move of the Virtual Machine to the new selected PM host
- Add the new VM subscription to the VSM in order to follow all the activity for that virtual machine
6. Every Z seconds (configurable in abiquo.properties), the Abiquo HA Check will detect that all the VM tasks on the PM have completed
- The newly moved VMs will be marked for deletion once the original host is powered on to avoid duplicates
- The resources of the deleted VM machines will become available again
7. The affected PM is then set as "disabled by HA" having had all or some of its VMs moved to new hosts:
- When you manually re-enable a PM disabled by HA, Abiquo:
- checks the physical machine
- subscribes it to the VSM
- enables the physical machine.