Understanding the Layers of High Availability
Even in non-virtualized environments, there are multiple ways to achieve high availability for Operating System (OS) instances and applications. When you introduce virtualization into the mix with vSphere, you gain additional methods of providing high availability. Figure 7.1 shows these various layers.
FIGURE 7.1 Each layer has its own forms of high availability.
At each layer are tools and techniques for providing high availability and business continuity:
- At the Application layer, options include Oracle Real Application Clusters (RAC), or simply application resiliency through a micro-services architecture.
- At the OS layer, solutions include OS clustering functionality, such as Windows Server Failover Clustering (WSFC).
- The Virtualization layer offers a number of features for high availability, including vSphere High Availability (HA), vSphere Fault Tolerance (FT), and stretched (metro) storage clusters.
- At the Physical layer, high...
