How a load balancer distributes incoming work
A load balancer directs incoming requests across multiple servers according to a chosen policy. It may rotate between servers or consider their current load and health. Distributing requests can improve capacity and resilience, but adding servers helps only if the rest of the application can support the extra work.
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One entry point, several possible workers
A load balancer receives traffic and chooses a backend to handle it. Different policies can favour simple rotation, fewer active connections or other measures.
Health checks help it avoid sending new requests to servers that appear unavailable. These checks are useful signals, but they must reflect meaningful application health to detect the right failures.
More front-end servers do not eliminate every bottleneck. A shared database, storage system or external service may still limit the application.
- Routing distributes requests.
- Health checks influence which servers are eligible.
- Shared state must remain available where needed.
If a user's session exists only in one server's memory, a later request sent elsewhere may not find it. Applications address this through approaches such as shared session storage or carefully designed routing behaviour.