The Site Reliability Workbook

Chapter 11. Managing Load

By Cooper Bethea, Gráinne Sheerin, Jennifer Mace, and Ruth King with Gary Luo and Gary O’Connor

No service is 100% available 100% of the time: clients can be inconsiderate, demand can grow fifty-fold, a service might crash in response to a traffic spike, or an anchor might pull up a transatlantic cable. There are people who depend upon your service, and as service owners, we care about our users. When faced with these chains of outage triggers, how can we make our infrastructure as adaptive and reliable as possible?

This chapter describes Google’s approach to traffic management with the hope that you can use these best practices to improve the efficiency, reliability, and availability of your services. Over the years, we have discovered that there’s no single solution for equalizing and stabilizing network load. Instead, we use a combination of tools, technologies, and strategies that work in harmony to help keep our services reliable.

Before we dive in to this chapter, we recommend reading the philosophies discussed in Chapters 19 (“Load Balancing at the Frontend”) and 20 (“Load Balancing in the Datacenter”) of our first SRE book.

Google Cloud Load Balancing

These days, most companies don’t develop and maintain their own global load balancing solutions, instead opting to use load balancing services from a larger public cloud provider. We’ll discuss Google Cloud Load Balancer (GCLB) as a concrete example of large-scale load balancing, but nearly all ...