Introducing the OpenStack logical architecture

Before delving into the OpenStack architecture , we need to refresh or fill gaps and learn more about the basic concepts and usage of each core component.

In order to get a better understanding on how it works, it will be beneficial to first briefly parse the things, which make it work. In the following sections, we will look at various OpenStack services, which work together to provide the cloud experience to the end user. Despite the different services catering to different needs, they follow a common theme in their design that can be summarized as follows:

• Most OpenStack services are developed in Python, which aids rapid development.
• All OpenStack services provide REST APIs. These APIs are the main external communication interfaces for services and are used by the other services or end users.
• The OpenStack service itself may be implemented as different components. The components of a service communicate with each other over the message queue. The message queue provides various advantages such as queuing of requests, loose coupling, and load distribution among the worker daemons.

With this common theme in mind, let's now put the essential core components under the microscope and go a bit further by asking the question: What is the purpose of such  component?