Scaling the cluster out¶

Canonical OpenStack scales out, meaning that you can add more machines to the cluster if you need more resources or if you’re designing the cloud for high availability.

Make sure you get familiar with the following sections before proceeding with any instructions listed below:

Scaling the cluster out using the manual bare metal provider¶

The following section provides instructions on scaling the cluster out with the manual bare metal provider.

Requirements¶

You will need:

Canonical OpenStack already installed using the manual bare metal provider
one dedicated physical machine with:
- hardware specifications matching minimum hardware specifications as documented under the Enterprise requirements section
- fresh Ubuntu Server 24.04 LTS installed

If you can’t provide an unlimited access to the Internet, see the Manage a proxied environment section.

Create a registration token¶

Warning

Clustering does not support base hostnames. Nodes are only recognized by their FQDNs.

A registration token has to be created first for the other machine to be able to join the existing Canonical OpenStack cluster.

In order to create a registration token for the new machine, execute the sunbeam cluster add command on the first machine in the cluster (aka primary node):

sunbeam cluster add FQDN --output FILE

FQDN is a fully qualified domain name (FQDN) of the machine being added.

FILE is a name of the file where to save the registration token.

For example, to create a registration token for the cloud-2 machine from the Example physical configuration section, execute the following command on the cloud-1 machine:

sunbeam cluster add cloud-2.example.com --output cloud-2.asc

Sample output:

Token written to file: /home/ubuntu/cloud-2.asc

Copy the file with the token (here cloud-2.asc) to the machine that you want to add to the cluster.

Provision the new machine¶

Switch to the machine that you want to add and proceed with the provisioning procedure described below.

Install the snap¶

First, install the openstack snap:

sudo snap install openstack

This will install the latest stable version by default. You can use the --channel switch to install a different version of OpenStack instead. All machines in the cluster must have the same version of OpenStack installed.

Prepare the machine¶

To prepare the machine for Canonical OpenStack usage, execute the following command:

sunbeam prepare-node-script | bash -x && newgrp snap_daemon

This command will:

ensure all required software dependencies are installed, including the openssh-server,
configure passwordless access to the sudo command for all terminal commands for the currently logged in user (i.e. NOPASSWD:ALL).

Add the machine to the cluster¶

In order to add the machine to the cluster, execute the sunbeam cluster join command on that machine

cat FILE | sunbeam cluster join --role ROLES -

FILE is a name of the file with the registration token.

ROLES` is a comma-separated list of roles (control, compute, storage) to assign to the machine being added.

For example, to add the cloud-2 machine from the Example physical configuration section, execute the following command:

cat cloud-2.asc | sunbeam cluster join --role control,compute,storage -

One finished, you should be able to see the following message on your screen:

Node joined cluster with roles: storage, control, compute

Resize the cluster¶

When provisioning new machines with the control role assigned, the cluster needs to be resized to make use of those machines for the purpose of hosting control functions.

To resize the cluster, execute the following command on any of the machines:

sunbeam cluster resize