Chapter 11. AlwaysOn Availability Groups

AlwaysOn Availability Groups is the most common High Availability technology used in SQL Server. It persists multiple copies of databases, eliminating storage from being the single point of failure. It also allows you to scale read workload through multiple readable secondary nodes.

In this chapter, I’ll provide an overview of how Availability Groups work internally and explain how to troubleshoot common issues. You will learn about the overhead introduced by synchronous replicas and readable secondaries. Finally, I will discuss Availability Groups monitoring and cover how to troubleshoot failover events.

AlwaysOn Availability Groups Overview

Perhaps the easiest way to explain how AlwaysOn Availability Groups work is to look at the history of this technology. It was introduced in SQL Server 2012 as the replacement and successor to Database Mirroring, which used to have the internal ...

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