OpenStack is an open-source software cloud computing infrastructure platform. It is a free and open-source platform released under the Apache 2 License. OpenStack architecture consists of several software components that provide Infrastructure as a Service (IaaS). These co-operative components are organized into five main groups: compute, storage, networking, identity, and dashboard.

What is OpenStack Architecture?

OpenStack is a cloud computing platform that enables businesses and organizations to create and manage virtual private clouds. It is designed to be highly scalable and easy to use, with a focus on openness and collaboration. The OpenStack platform comprises several core components, each providing different features and functionalities. These components include the Nova compute service, the Glance image service, the Keystone identity service, the Cinder block storage service, and the Neutron networking service. Together, these components provide all the building blocks necessary for businesses to deploy and manage their private clouds.

openstack architecture


Nova is a cloud computing platform that provides compute services. It is one of the most critical components of the OpenStack cloud infrastructure. Nova is written in Python and uses the SQLAlchemy database library. Nova’s modular architecture allows it to be integrated with other OpenStack services. Nova provides various features, including support for multiple hypervisors, live migration of virtual machines, and automatic failover. In addition, Nova integrates with other OpenStack services to provide a complete cloud computing solution.


The Image service (glance) project provides a service where users can upload and discover data assets that are meant to be used with other services. This currently includes images and metadata definitions. Glance image services include discovering, registering, and retrieving virtual machine (VM) images. Glance has a RESTful API that allows querying of VM image metadata as well as retrieval of the actual image.



Cinder is an effective block storage service used to manage and store large amounts of data. Cinder provides several features that make it an ideal solution for storing data, including the ability to create and manage snapshots, create and attach volumes, and mount and unmount volumes. In addition, Cinder offers many benefits, such as the ability to scale up or down as needed and use multiple storage devices. As a result, Cinder is an ideal solution for managing and storing data in the cloud.


Neutron, which provides networking services, is a popular choice for cloud infrastructure. It is open-source, so it benefits from a large community of developers and users and is compatible with a wide range of other software. Neutron is also flexible, allowing administrators to select the features and functionality that best meet their needs. However, Neutron can be complex to configure and manage, requiring a significant investment of time and resources. For these reasons, OpenStack Neutron is best suited for large-scale deployments.


Keystone is a critical component of any OpenStack deployment, providing centralized authentication and authorization for all users and services. Its flexible design supports multiple authentication backends, making it easy to integrate with existing identity management systems. In addition, Keystone provides various features to help manage user accounts and permissions, including creating and managing projects and groups, assigning users roles, and controlling access to OpenStack resources. As a result, Keystone is an essential part of any OpenStack deployment, offering a powerful and flexible solution for managing user identities and permissions.


Horizon is a web-based graphical interface that makes it easy to manage OpenStack resources. With Horizon, you can quickly provision and manage virtual machines, networking, storage, and other resources. Horizon also provides an advanced user interface for managing complex deployments. In addition, Horizon integrates with other OpenStack services, making it easy to orchestrate your entire cloud infrastructure from a single platform.

The OpenStack controller

The Controller is the central point of contact for all OpenStack services. It is responsible for authenticating users, dispatching requests to the appropriate service, and providing a single entry point for all API calls. The controller also serves as a central repository for all OpenStack metadata, such as images, flavors, and user information. In addition, the controller provides an audit trail for all API calls, making it an essential tool for debugging and troubleshooting. Ultimately, the OpenStack controller is responsible for ensuring that all OpenStack services run smoothly and that user data is secure.

components of openstack

Compute nodes

Compute nodes provide the computational resources for an OpenStack deployment. Each compute node contains one or more processors, memory, and local storage. The compute nodes are connected to the network through a switch. The compute nodes run the OpenStack compute service, responsible for managing virtual machines’ life cycle. The compute service provides an API that allows users to create, delete, and modify virtual machines. In addition, the compute service can schedule tasks on the compute nodes, such as starting virtual machines or taking snapshots. The compute nodes also provide storage for the virtual machine images and other data. The OpenStack Storage service manages the storage on the compute nodes. The storage service provides an API that allows users to create, delete, and modify storage volumes. In addition, the storage service can attach storage volumes to virtual machines or take snapshots of storage volumes.

Storage nodes

OpenStack Storage (Cinder) is one of the core components of OpenStack. It provides block-level storage devices for OpenStack compute instances (Nova). Cinder volume can be attached to an instance and used like any other block device. In addition, Cinder provides a REST API that enables administrators to manage and provision storage devices. OpenStack storage nodes are typically deployed on dedicated hardware. 

These can be either physical servers or virtual machines. Storage nodes must access durable storage devices, such as hard drives or SSDs. In addition, each storage node must have enough memory and CPU resources to support the number of volumes it will be responsible for managing. Therefore, administrators must select the appropriate number and size of storage nodes when configuring a new OpenStack deployment to ensure optimal performance and high availability.

Networking nodes

The OpenStack Networking service, commonly referred to as Neutron, provides network connectivity as a service between interface devices (e.g., vNICs) managed by other OpenStack services (e.g., compute [Nova] and storage [Cinder]). Central to this goal is the L3 agent, which provides support for routers, NAT, and floating IPs. The L3 agent can run on a central node or each computed node. The former simplifies networking administration but may incur a higher networking overhead. In the past, most deployment options for OpenStack used flat networks that did not provide scalable multi-tenancy or allow fine-grained control over traffic flows. Because of this, operators were forced to overprovision network Capacity and underutilize server Capacity. 

The introduction of software-defined networking (SDN) controller support in OpenStack Neutron has changed this paradigm by allowing the creation of highly available, scalable, and flexible software-based networks. Hardware requirements for the nodes depend on the size and number of devices in the OpenStack Installation. A minimum of two NICs is recommended for each node. As a best practice, it is recommended to use three NICs: one for management traffic, storage traffic, and one for public (or external) traffic.

Get Started Today!

OpenStack is a powerful platform that can create and manage cloud computing environments. However, with its growing popularity, businesses need to learn how OpenStack works and how they can use it to their advantage. Contact Digital Data today if you are interested in learning more about OpenStack or need help getting started. Our team of experts would be happy to assist you with your OpenStack needs.