A load balancer is a critical component in any high-availability architecture. It sits between the user and your backend servers, distributing incoming traffic to ensure no single server becomes a bottleneck.
1. Round Robin
The simplest strategy. Incoming requests are distributed sequentially to each server in the pool. It's easy to implement but doesn't account for varying server loads.
2. Weighted Round Robin
Similar to Round Robin, but each server is assigned a weight based on its capacity. Servers with higher weights receive more traffic.
3. Least Connections
Sends new requests to the server with the fewest active connections. This is ideal for requests that vary significantly in processing time.
4. IP Hash
Uses the client's IP address to determine the server. This ensures session persistence, though external session stores are usually a better choice for modern apps.