All business continuity provisions involve hardware and software redundancy, data replication and some means of failover and failback. Purpose-built failover clustering software has long been among the most popular choices based on its proven dependability and cost-effectiveness. The clusters are relatively easy to deploy in an enterprise data center using shared storage. But with no shared storage available in the public cloud, configuring failover clusters in Azure becomes considerably more challenging.
This article by Dave Bermingham examines the options available for high availability (HA) and disaster recovery (DR) provisions within and for the Azure cloud. Special emphasis is given to SQL Server as a particularly popular application for Azure.