Building a cluster of single-board mini-computers is an excellent way to explore and learn about distributed computing. With the scarcity of Raspberry Pi boards, and the prices starting to get prohibitive for some projects, alternatives such as Orange Pi have gained popularity.
In this article, I’ll show you how to build a (surprisingly cheap) 4-node cluster packed with 16 cores and 4GB RAM to deploy a MariaDB replicated topology that includes three database servers and a database proxy, all running on a Docker Swarm cluster and automated with Ansible.