Chapter 7. High availability and redundancy
I can’t count the number of times that something in IT has failed me. I’ve had a laptop hard drive crash the day before a conference, a smoking power supply in an email server, and failed network interfaces on a core router. And don’t even get me started on OS, driver, and firmware updates! I’m sure that anyone who works in IT would love to share horror stories of situations they’ve had to deal with—usually problems the happened late at night or at a critical time for the business. Is there ever such a thing as a good failure, and at a nice time?
If you anticipate failures in IT, you learn to plan and design your applications to accommodate problems. In this chapter, you’ll learn how to use Azure high availability and redundancy features to minimize disruptions caused by maintenance updates and outages. This chapter builds a foundation for the next two or three chapters as you start to move from an application that runs on a single VM or web app, to one that can scale and be globally distributed.