This document discusses approaches to achieving high availability for MySQL databases. It introduces replication, DRBD (Distributed Replicated Block Device), master-to-master replication, and MySQL Cluster as options. For each approach, it provides a conceptual overview and discusses pros and cons. The document recommends using DRBD for applications that require data consistency and master-to-master replication for high performance applications. It concludes by advising readers to evaluate their specific high availability needs and budget to choose a suitable solution.