Masakari service overview

Masakari provides Virtual Machines High Availability(VMHA), and rescues KVM-based Virtual Machines(VM) from a failure events described below:

• VM process down - restart vm (use nova stop API, and nova start API). Libvirt events will be also emitted by other failures.

• Provisioning process down - restarts process, changes nova-compute service status to maintenance mode (use nova service-disable).

• nova-compute host failure - evacuate all the VMs from failure host according to the following recovery methods (use nova evacuate API).

  • auto - evacuate all the VMs with no destination node for nova scheduler.

  • reserved_host - evacuate all the VMs with reserved hosts as the destination nodes for nova scheduler.

  • auto_priority - evacuate all the VMs by using auto recovery method firstly. If failed, then using reserved_host recovery method.

  • rh_priority - evacuate all the VMs by using reserved_host recovery method firstly. If failed, then using auto recovery method.

The below services enables deplores to integrate with the Masakari directly or through custom plug-ins.

The Masakari service consists of the following components:

masakari-api

An OpenStack-native REST API that processes API requests by sending them to the masakari-engine over Remote Procedure Call (RPC).

masakari-engine

Processes the notifications received from masakari-api by executing the recovery workflow in asynchronous way.