Local Load Balancing
Load balancing is a method for evenly distributing processing or service requests across devices in a network. At AppNexus we use "load balancing" primarily to mean local load balancing within a datacenter, rather than global load balancing between datacenters.
With local load balancing, identical instances are clustered into a pool and a load balancer distributes traffic among the instances, or nodes, in the pool. It is most commonly used either to enlarge capacity or for redundancy.
Each AppNexus datacenter uses a redundant pair of F5 BIG-IP 6400 Local Traffic Managers (LTMs) for local load balancing. The LTMs are in constant communication with each other; if the primary fails, the secondary will immediately take over.
A Few Additional Features of Our Load Balancing Pools:
- It's easy to create and manage load balancing pools using our API command-line tools. You also have the flexibility to write your own tools that can interact directly with our API.
- We support session persistence; this means that session-specific information is collected and stored on a specific server, and a client is automatically directed to that same server on subsequent visits.
- We support SSL for secure communication.
Next core concept: Global Load Balancing