The Neutron load-balancing-as-a-service plugin, known as LBaaS v2, provides users with the ability to load balance traffic to applications running on virtual instances in the cloud. Neutron provides an API to manage load balancers, listeners, pools, members, and health monitors.
In this chapter, we will cover some fundamental load balancing concepts, including the following:
- Listeners, pools, and pool members
- Load balancing algorithms
- Health Monitors
- Session Persistence
Neutron uses drivers to interact with hardware or software load balancers. In Pike, the reference driver deploys HAProxy within network namespaces. HAProxy is a free, open source load balancer that is available for most Linux-based operating systems. Octavia is another open source load balancing solution that is compatible with the LBaaS v2 API. Rather than use network namespaces, however, Octavia spins up and manages a fleet of virtual machines, containers, or bare-metal servers known as amphorae that act as load balancers. This allows Octavia to scale horizontally and on-demand. Deploying Octavia and other third-party drivers from vendors such as F5, Citrix, Radware, and more is possible, but outside the scope of this book.
In this chapter, we will work through the following:
- Integrating load balancers into the network
- Installing and configuring the LBaaS v2 agent
- Creating a load balancer
- Demonstrating load balanced traffic to instances