Learn which design considerations to take into account when architecting the cloud

Key Value
Summary Design considerations.
Categories openstack
Difficulty 2
Author Tytus Kurek tytus.kurek@canonical.com

Overview

Duration: 3 minutes

Before you get started!

Welcome to OpenStack!

In this series of tutorials, we will walk you through all the necessary steps to install, configure and get started with OpenStack. Using just three dedicated machines, you will learn how to deploy OpenStack in highly available, multi-node, production-grade clusters.

This tutorial is the first in the “Phase II - Deploying OpenStack” series.

Explore other tutorials >

What is OpenStack?

OpenStack is a collection of open source projects designed to work together to form the basis of a cloud. OpenStack can be used for both private and public cloud implementation.

What is Sunbeam?

Sunbeam is an upstream project under the governance of the OpenInfra Foundation (OIF), which was created to lower the barrier to entry for OpenStack, simplify its adoption process, and set the foundation for an autonomous private cloud. Sunbeam uses cloud-native architecture and total bottom-up automation to make OpenStack more accessible to newcomers and to help users get to grips with the platform immediately.

What is MicroStack?

MicroStack (based on Sunbeam) is an OpenStack distribution designed for small-scale cloud environments. While it is available with full commercial support from Canonical, it can also be self-deployed with no friction, effectively eliminating the need for a paid consulting engagement. MicroStack currently includes core OpenStack services only, but is expected to evolve quickly to ensure full feature parity with Canonical’s Charmed OpenStack soon.

In this tutorial, you will learn how to:

  • Make the right decisions when planning an OpenStack deployment

You will only need:

  • Theoretical knowledge of OpenStack gained by completing all tutorials in the “Phase I - Learning OpenStack” series

Design considerations

Duration: 25 minutes

There are multiple design considerations that need to be taken into account before proceeding with an OpenStack deployment. Analysing them thoroughly and adjusting your cloud design accordingly will help you avoid costly changes at further stages of your OpenStack deployment project. Please refer to the official OpenStack documentation and MicroStack documentation for more detailed information about each of the topics covered in this section.

Cloud architecture

OpenStack supports various types of cloud architectures, including the following:

  • Hyper-Converged - each node in the cluster hosts control, compute and storage functions.
  • Converged - each node in the cluster hosts compute and storage functions, while dedicated nodes exist to run the OpenStack control plane.
  • Fully-Disaggregated - dedicated nodes exist to host individual cloud functions: control, compute and storage.

Sunbeam fully supports all above cloud architectures. Those can be modelled through the concept of roles specified during the initial bootstrap phase on the first node in the cluster, and when joining the cluster on other nodes.

Availability Zones

Availability Zones (AZs) are an end-user visible logical abstraction for partitioning a cloud without knowing the physical infrastructure. If designed properly, AZs provide segregation into failure domains, ensuring that any application deployed across multiple AZs can survive a failure of a single zone.

Sunbeam fully supports the concept of AZs. Those can be configured through the OpenStack client post-deployment.

Regions

Regions are general divisions of an OpenStack deployment with their own API endpoints and resources (compute, network and storage), while sharing the same identity records. The purpose of regions is to facilitate deployments of OpenStack across geographically distributed regions.

At the moment, Sunbeam only supports the default region - RegionOne.

Cells

Cells are OpenStack’s internal concept that enables cloud deployments on a large scale by sharding some of its internal components, such as databases and messaging queues.

In general, Canonical recommends running many small clouds rather than one big cloud.

At the moment, Sunbeam only supports the default cell - Cell 0.

Hardware requirements

Hardware used in OpenStack deployments must meet certain criteria to qualify for full commercial support from Canonical. Even though it might be technically possible to install the cloud on a different hardware, such configurations are neither recommended nor supported. Please refer to the MicroStack documentation for exact hardware requirements for production.

Bare metal automation

OpenStack can be deployed in two different modes with Sunbeam:

  • Without bare metal automation - the operator is responsible for the initial provisioning and configuration of all physical machines used in the OpenStack cluster setup.
  • With bare metal automation - Sunbeam relies on MAAS to provision and configure physical machines on-demand.

The decision whether or not to use bare metal automation with MAAS must be taken at the beginning of the deployment process. There is no way to transition from one mode to the other one once the deployment is complete.

Networking

Using multiple networks is recommended for traffic segregation purposes. Sunbeam requires at least two physical networks to be present on each node in the cluster when deploying OpenStack for production:

  • Control plane network - used to provide access to OpenStack service APIs.
  • External network - used to provide access to instances running on OpenStack.

Storage

Sunbeam uses Ceph as its default driver for Cinder. By default, it will take all un-partitioned disks found in all nodes in the cluster with the storage role assigned.

Plugins

By default, Sunbeam instals core OpenStack services only. Additional services and other components, such as observability stack, can be installed through the concept of plugins. Please refer to the MicroStack documentation for exact information about enabling and using individual plugins.

Third-party tools

Project Sunbeam fully relies on an upstream OpenStack code. As a result, Sunbeam-deployed clouds use standard OpenStack APIs. Any third-party tool, such as cloud platform management solution, that supports OpenStack APIs should theoretically work with Sunbeam-deployed clouds out-of-the-box.

Canonical invites vendors of such solutions to participate in Canonical’s Partner Program for joint testing and validation.

Non-standard components

For any non-standard components which require access to OpenStack services on a lower level than APIs, an additional layer of integration might be required.

Canonical invites vendors of such solutions to participate in Canonical’s Partner Program for joint design, implementation, testing and validation.

Commercial services

Even though project Sunbeam was created to lower the barrier to entry for OpenStack and minimise its operations burden, some organisations might still struggle when figuring out the right design, deploying it at scale and operating it post-deployment.

In response to those challenges, Canonical provides a whole gamut of commercial services. These include:

  • Consulting - design and delivery services
  • Support - phone and ticket support with guaranteed SLAs
  • Managed - fully-managed cloud service
  • Trainings - professional training courses

Next steps

Duration: 2 minutes

Congratulations! You have reached the end of this tutorial.

You can now move to the next tutorial - “2. Guided installation” - or explore other tutorials.

In this tutorial, you have learnt how to:

  • Make the right decision when planning an OpenStack deployment

Where to go from here?