Latest Load-Balancing Articles

Deploying a new application version without downtime requires more than starting new instances. Production traffic must move from the old version to the new version without routing requests to unready instances, interrupting in-flight work, or exposing an unhealthy release to every client .

Production traffic rarely travels directly from a client to an application server. A request typically passes through several network layers responsible for finding the service, selecting healthy capacity, terminating connections, and routing the request to the correct backend .

A load balancer needs more than a list of healthy servers. For every incoming request or connection, it must decide which backend should receive the traffic . That decision is controlled by the load-balancing algorithm.

Production load balancing is not simply about distributing requests across several servers. A reliable traffic layer must continuously decide where traffic can safely go, how failures affect routing, how capacity changes, and how application instances enter and leave production .

Load balancing distributes incoming requests across multiple servers, containers, or service instances so that no single backend becomes a bottleneck. It is one of the fundamental building blocks behind scalable and highly available production systems .

A load balancer can protect an application from individual backend failures, but only if the load-balancing layer itself is highly available . Replacing one application server with one load balancer simply moves the single point of failure.

Load balancers normally distribute requests across multiple interchangeable application instances. This works best when any healthy instance can process any request. Problems appear when an application stores user-specific state locally and later requests must return to the same server.