fuel-docs/pages/reference-architecture/0015-closer-look.rst

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Reference Architectures: Multi-node with HA Details

Details of Multi-node with HA Deployment

In this section, you'll learn more about the Multi-node with HA deployment configuration and how it achieves high availability. As you may recall, this configuration looks something like this:

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OpenStack services are interconnected by RESTful HTTP-based APIs and AMQP-based RPC messages. So redundancy for stateless OpenStack API services is implemented through the combination of Virtual IP (VIP) management using Pacemaker and load balancing using HAProxy. Stateful OpenStack components, such as the state database and messaging server, rely on their respective active/active and active/passive modes for high availability. For example, RabbitMQ uses built-in clustering capabilities, while the database uses MySQL/Galera replication.

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Lets take a closer look at what an OpenStack deployment looks like, and what it will take to achieve high availability for an OpenStack deployment.