8 Load-balancing applications

 

An important component of highly available applications is how to distribute traffic across all your VMs. In chapter 7, you learned the difference between Availability Zones and Availability Sets, as well as how you can create multiple VMs across Azure datacenters or regions to provide application redundancy. Even if you have all these highly available and distributed VMs, that doesn’t help if only one VM receives all the customer traffic.

Load balancers are network resources that receive the incoming application traffic from your customers, examine the traffic to apply filters and load-balancing rules, and then distribute the requests across a pool of VMs that run your application. In Azure, there are a couple of ways to load-balance traffic, such as if you need to perform SSL off-loading on large applications that use encrypted network traffic. In this chapter, you’ll learn about the various load-balancer components, and how to configure traffic rules and filters and distribute traffic to VMs. You’ll build on the high-availability components from chapter 8 and get ready for chapter 9, which covers how to scale resources.

8.1 Azure load-balancer components

8.1.1 Creating a frontend IP pool

8.1.2 Creating and configuring health probes

8.1.3 Defining traffic distribution with load-balancer rules

8.1.4 Routing direct traffic with Network Address Translation rules

8.1.5 Assigning groups of VMs to backend pools

8.2 Creating and configuring VMs with the load balancer

8.3 Lab: Viewing templates of existing deployments