Instance HA service

Instance High Availability Service or Masakari is an OpenStack project designed to ensure high availability of instances and compute processes running on hosts.

The service consists of the following microservices:

  • API recieves requests from users and events from monitors, and sends them to engine

  • Engine executes recovery workflow

  • Monitors detect failures and notifies API. MOS uses monitors of the following types:

    • Instance monitor performs liveness of instance processes

    • Host monitor performs liveness of a compute host, runs as part of the Node controller from the OpenStack controller

    Note

    The Processes monitor is not present in MOS as far as HA for the compute processes is handled by Kubernetes.