Deploy an additional nova cell v2

Warning

Multi cell support is only supported in Stein and later versions.

The different sections in this guide assume that you are ready to deploy a new overcloud, or already have installed an overcloud (min Stein release).

Note

Starting with CentOS 8 and the TripleO Stein release, podman is the CONTAINERCLI to be used in the following steps.

The minimum requirement for having multiple cells is to have a central OpenStack controller cluster running all controller services. Additional cells will have cell controllers running the cell DB, cell MQ and a nova cell conductor service. In addition there are 1..n compute nodes. The central nova conductor service acts as a super conductor of the whole environment.

For more details on the cells v2 layout check Cells Layout (v2)

• Example 1. - Basic Cell Architecture in Train release
  • Extract deployment information from the overcloud stack
    • Export EndpointMap, HostsEntry, AllNodesConfig, GlobalConfig and passwords information
    • Create roles file for the cell stack
    • Create cell parameter file for additional customization (e.g. cell1/cell1.yaml)
    • Create the network configuration for cellcontroller and add to environment file
  • Deploy the cell
    • Create new flavor used to tag the cell controller
    • Run cell deployment
  • Create the cell and discover compute nodes (ansible playbook)
  • Create the cell and discover compute nodes (manual way)
    • Add cell information to overcloud controllers
    • Extract transport_url and database connection
    • Create the cell
    • Perform cell host discovery
    • Create and add the node to an Availability Zone
• Example 2. - Split Cell controller/compute Architecture in Train release
  • Extract deployment information from the overcloud stack
    • Create roles file for the cell stack
    • Create cell parameter file for additional customization (e.g. cell1/cell1.yaml)
    • Create the network configuration for cellcontroller and add to environment file
  • Deploy the cell
    • Create new flavor used to tag the cell controller
    • Run cell deployment
  • Create the cell
  • Extract deployment information from the cell controller stack
    • Export EndpointMap, HostsEntry, AllNodesConfig, GlobalConfig and passwords information
    • Create cell compute parameter file for additional customization
  • Deploy the cell computes
    • Run cell deployment
    • Perform cell host discovery
    • Create and add the node to an Availability Zone
• Example 3. - Advanced example using split cell controller/compute architecture and routed networks in Train release
  • Used networks
  • Prepare control plane for cell network routing
  • Reuse networks and adding cell subnets
  • Export EndpointMap, HostsEntry, AllNodesConfig, GlobalConfig and passwords information
  • Cell roles
  • Create the cell parameter file
  • Virtual IP addresses
  • Create the network configuration for cellcontroller and add to environment file
  • Deploy the cell controllers
    • Create new flavor used to tag the cell controller
    • Run cell deployment
  • Create the cell
  • Extract deployment information from the cell controller stack
  • Create cell compute parameter file for additional customization
  • Reusing networks from control plane and cell controller stack
  • Deploy the cell computes
    • Run cell deployment
    • Perform cell host discovery
    • Create and add the node to an Availability Zone
• Additional cell considerations and features
  • Availability Zones (AZ)
    • Configuring AZs for Nova (compute)
  • Routed networks
  • Reusing networks from an already deployed stack
  • Configuring nova-metadata API per-cell
• Managing the cell
  • Add a compute to a cell
  • Delete a compute from a cell
  • Delete a cell
  • Updating a cell