What is a Cloud Load Balancer?

by Bethany Hill on Cloud • December 23, 2020

Cloud load balancing can be implemented to operate at either Layer 4 (transport layer) or Layer 7 (application layer) of the OSI networking model.

Layer 4 load balancing entails distributing traffic for protocols that operate at the transport layer (TCP, UDP) and sometimes at the network layer (IP). Layer 7 load balancing operates at the application layer and makes balancing decisions based on data content and metadata available at that layer.

Different hashing algorithms can be employed to act on the data available at the relevant OSI networking layer to facilitate decision making around the distribution of client traffic. Various criteria can be used to distribute traffic between end-points such as turn-based, weighted or persistent routing.

The cloud load balancing software sits between the pool of backend servers and the clients, ensuring that the client gets routed to the most desirable backend server. Health monitors are used to ensuring that the traffic is only sent to healthy backend servers by taking the faulty server out of the load-balancing pool. This provides the optimal experience for clients.

Cloud load balancers have multiple benefits over traditional on-premises hardware devices. The global nature of cloud appliances and the ease of deploying a software-based cloud load balancer make demand scalability and flexible control of cloud load balancers possible. It also ensures redundancy by running in multiple geographical locations.