An F5 load balancer is a device that acts as a reverse proxy and distributes network or application traffic across a number of servers. Load balancers are used to increase capacity (concurrent users) and reliability of applications. F5 load balancers are generally grouped into two categories: Layer 4 and Layer 7. Layer 4 load balancers act upon data found in network and transport layer protocols (IP, TCP, FTP, UDP), while Layer 7 load balancers distribute requests based upon data found in application layer protocols such as HTTP. Requests are received by both types of load balancers and they are distributed to a particular server based on a configured algorithm. Some industry standard algorithms include round-robin, least connections, and IP hash. Layer 7 load balancers can further distribute requests based on application-specific data such as HTTP headers, cookies, or data within the application message itself.
F5 load balancers ensure reliability and availability by monitoring the "health" of applications and only sending traffic to servers that are online. They can also redirect traffic to other servers that could handle the load in cases where a server is down or overloaded, ensuring seamless failover. F5 offers intelligent and customizable load balancing policies to inspect and route customers to available resources, freeing up busy sites and systems. They also provide highly available, intelligent load balancing and traffic policy management across preferred cloud providers. F5 load balancing solutions sit inline to customer and application traffic, providing live telemetry and unique traffic insights to how applications perform and how customers experience them.
