To achieve load balancing, you need to select appropriate algorithms such as polling, minimum connection, etc. to ensure that the backend server is configured consistently and is located in the private network, then configure the load balancer's health check and session maintenance functions, and finally continuously monitor traffic and performance and adjust them in time. 1. Select a load balancing method suitable for use cases, such as polling is suitable for servers with similar configurations, with minimal connections suitable for dynamic loads. 2. Make sure the same service is run and the unified configuration is used when setting up the backend server. 3. Enable health checks, SSL termination, and session persistence when configuring the load balancer. 4. Use tools to continuously monitor traffic patterns, server performance, and error rates to optimize configuration.

Load balancing is all about spreading traffic across multiple servers so no single one gets overwhelmed. It helps improve responsiveness, reliability, and availability of your applications or websites. Here's how to actually do it.

Choose the Right Load Balancing Method

There are several common algorithms that determine how traffic gets distributed:

• Round Robin : Sends requests sequentially to each server in the group.
• Least Connections : Directs traffic to the server with the fewest active connections.
• IP Hash : Routes traffic based on the client's IP address, which can help maintain session persistence.
• Weighted Methods : Assigns more traffic to stronger or higher-capacity servers.

Pick one that fits your use case — for example, Round Robin works well for servers with similar specs, while Least Connections suits dynamic workloads.

Set Up Your Backend Servers First

Before configuring the load balancer, make sure your backend servers are ready:

• They should be running the same application or service.
• Ideally, they're behind a private network to reduce exposure.
• Use identical configurations (like SSL certificates) to avoid mismatches.

If you're using cloud services like AWS or GCP, this often means launching multiple instances from the same image or template.

Configure the Load Balancer

Once your backend is set up, configure the load balancer itself. This varies depending on whether you're using hardware, software, or a cloud provider:

• Health Checks – Set up regular checks to ensure only healthy servers receive traffic.
• Session Persistence (Sticky Sessions) – Enable if needed, especially for apps that store session data locally.
• SSL Termination – Offload encryption/decryption to the load balancer if possible, reducing backend load.

For example, if you're using NGINX as a load balancer, your config might look like this:

 upstream backend {
    least_conn;
    server 192.168.0.10;
    server 192.168.0.11;
    keepalive 32;
}

Monitor and Adjust Over Time

Even after everything's working, don't just walk away. Keep an eye on:

• Traffic patterns — maybe your current method isn't ideal during peak times.
• Server performance — swap out underperformance nodes or adjust weights.
• Error rates — suddenly spikes may indicate configuration issues or failing backends.

Tools like Prometheus, Grafana, or even built-in cloud monitoring dashboards can help track these metrics.

That's basically it — not too complicated once you understand the flow, but easy to get wrong if you skip steps like health checks or consistent backend setup.

The above is the detailed content of How do I use load balancing to distribute traffic across multiple servers?. For more information, please follow other related articles on the PHP Chinese website!