IP hash for session persistence in Nginx - Mini Project: Build & Apply

IP Hash for Session Persistence with Nginx

📖 Scenario: You are setting up a simple web server load balancer using Nginx. Your goal is to ensure that users keep connecting to the same backend server during their session. This is important for applications that store session data locally on each server.

🎯 Goal: Configure Nginx to use the ip_hash method for load balancing, so that each user's requests are consistently sent to the same backend server based on their IP address.

📋 What You'll Learn

Create an Nginx upstream block named backend with three servers: 192.168.1.10, 192.168.1.11, and 192.168.1.12

Add the ip_hash directive inside the upstream block to enable session persistence

Configure the server block to proxy requests to the backend upstream

Print the final Nginx configuration to verify the setup

💡 Why This Matters

🌍 Real World

Many web applications require users to stay connected to the same server during their session to keep their data consistent. Using IP hash in Nginx helps achieve this without complex session sharing.

💼 Career

Understanding how to configure load balancing and session persistence is a key skill for DevOps engineers managing scalable web services.

1

Create the upstream block with backend servers

Create an Nginx upstream block called backend with these exact servers: 192.168.1.10, 192.168.1.11, and 192.168.1.12. Use the syntax: server 192.168.1.10; for each server.

Nginx

# Your code here

Need a hint?

Use the upstream directive to group backend servers.

2

Add the ip_hash directive for session persistence

Inside the existing upstream backend block, add the directive ip_hash; on its own line before the server entries.

Nginx

upstream backend {
    # Add ip_hash directive below

    server 192.168.1.10;
    server 192.168.1.11;
    server 192.168.1.12;
}

Need a hint?

The ip_hash directive must be inside the upstream block before the servers.

3

Configure the server block to proxy requests to backend

Create an Nginx server block that listens on port 80 and proxies all requests to the backend upstream using proxy_pass http://backend; inside the location / block.

Nginx

upstream backend {
    ip_hash;
    server 192.168.1.10;
    server 192.168.1.11;
    server 192.168.1.12;
}

# Add server block below

Need a hint?

Use proxy_pass inside location / to forward requests to the upstream.

4

Print the final Nginx configuration

Print the entire Nginx configuration including the upstream backend block with ip_hash and the server block proxying to backend.

Nginx

# Print the full configuration below

Need a hint?

Use a print statement to show the full configuration exactly as written.