Load Balancers Glossary

DigitalOcean Load Balancers are a fully-managed, highly available network load balancing service. Load balancers distribute traffic to groups of Droplets, which decouples the overall health of a backend service from the health of a single server to ensure that your services stay online.

This glossary defines the core concepts behind load balancers to help build your mental model of how load balancers work and understand what the documentation is referring to when it uses certain terminology.

Autobahn|Testsuite is a fully-automated testsuite that verifies client and server implementations of the Websocket Protocol.
In load balancing, a backend pool is a group of resources, such as Droplets, whose traffic are managed by the load balancer.
A handshake is the authentication process between two networked devices to ensure that both devices are who they claim to be.
A health check is a scheduled HTTP or TCP request that you can configure to run on a repeating basis to ensure that a service is healthy.
High Availability (HA) is an approach to infrastructure design focusing on reducing downtime and eliminating single points of failure.
Keep-Alive, or keepalive, is a signal sent from one device to another in order to maintain the connection between the two devices.
A load balancer distributes traffic across a backend pool of servers to improve the stability and responsiveness of an application.
A proxy is a computer or software system that acts as a dedicated intermediary between an endpoint device and another server.
SSL certificate is a digital document outlining the identity of the website.
SSL passthrough is the process of passing SSL-encrypted traffic on to a backend server for decryption.
SSL termination is the process of decrypting traffic encrypted with SSL.
Sticky session, or session persistence occurs when the load balancer creates a connection between a network and a user for a direction of the session.
Tags are keywords associated with resources which help with managing resource ownership and organize lookups and actions on resources.
Transport Layer Security (TLS) is a security protocol focused on privacy and data security for communication across the internet.
User Datagram Protocol, or UDP, is an established low-latency connection communication protocol between applications.