In this sample chapter from Exam Ref 70-764 Administering a SQL Database Infrastructure, learn how to design appropriate high availability and disaster recovery solutions in SQL Server with special attention to installation, configuration, and administration processes.
It is important to understand the difference between high availability and disaster recovery. It is not uncommon for management in organizations to misunderstand these concepts and use the wrong technology for their SQL Server infrastructure. In this last chapter, we examine the high availability technologies available in SQL Server, as promised in Chapter 2, “Manage backup and restore of databases.”
With high availability, you are using technology in SQL Server to minimize the downtime of a given database solution to maximize its availability. With disaster recovery, however, you are using technology to recover from a disaster incident, potentially minimizing the amount of data lost. In some cases, data loss is acceptable, because the imperative is to get your database solution online as soon as possible. That is why it is critical to engage with all stakeholders to determine the business requirements. With both high availability and disaster recovery people and processes play a key part, so make sure you don’t focus solely on the technology.
The exam will test your ability to design the appropriate high availability solution for a given scenario, which is why Skill 4.1 starts with a discussion about high availability and the primary considerations for designing a particular solution. Skill 4.2 then covers the designing of a disaster recovery solution, which commonly goes hand-in-hand with a high availability solution. Given how we covered disaster recovery in Chapter 2, a detailed discussion will not be required here. Skill 4.3 examines the log shipping technology in SQL Server and how it is primarily used to provide disaster recovery. Skill 4.4 then details Availability Groups and examines how they can be used to provide both high availability and scale-out capability to your databases. Finally, in Skill 4.5 we implement failover clustering solutions. Although this high availability technology has been available since SQL Server 2000, it’s commonly used in the industry and should not be discounted as an old, unused technology. Microsoft keeps investing in failover clustering, and we will learn about how SQL Server can take advantage of cluster shared volumes.
High availability technologies are complex and involve a lot of set up and configuration, so this chapter has many figures that show you their installation, configuration, and administration processes. Make sure you examine the various options in the figures and listings in this chapter to best prepared for the exam.
Skills covered in this chapter:
Design a high availability solution
Design a disaster recovery solution
Implement log shipping
Implement Availability Groups
Implement failover clustering