How to Install Redis Cluster: A Step-by-Step Guide

Redis is a powerful in-memory data store widely used for caching, real-time analytics, and messaging. Installing a Redis Cluster enhances Redis with distributed data storage and high availability. This tutorial will guide you through installing a Redis Cluster from scratch, covering prerequisites, installation, cluster creation, and basic troubleshooting tips.

Prerequisites

Operating System: Linux distribution (Ubuntu, CentOS, etc.) or compatible Unix-like OS
Redis Version: Redis 3.0 or higher (cluster mode introduced in 3.0+)
Basic Linux command line knowledge
At least 3 machines or at least 6 Redis instances on a single machine for a functional cluster with replicas
Ports 6379-6385 open (one port per Redis instance) for cluster communication
TCP networking enabled between nodes

Step 1: Download and Install Redis

First, install Redis on all machines that will run nodes for the cluster. You can install a stable Redis version from source or package manager. For the latest stable Redis (recommended), install from source:

sudo apt update
sudo apt install build-essential tcl
curl -O http://download.redis.io/redis-stable.tar.gz
tar xzvf redis-stable.tar.gz
cd redis-stable
make
sudo make install

This installs the redis-server and redis-cli binaries globally.

Step 2: Prepare Redis Instances

For a cluster, you need multiple Redis instances, each listening on different ports.

Create separate directories for each instance, e.g., /etc/redis/7000, /etc/redis/7001, etc.
Copy a base Redis config file into each directory and customize:

mkdir -p /etc/redis/7000
cp redis-stable/redis.conf /etc/redis/7000/

Edit each redis.conf to set:

port 7000 (or whichever port you assign)
cluster-enabled yes
cluster-config-file nodes-7000.conf
cluster-node-timeout 5000
appendonly yes for data persistence (optional but recommended)
daemonize yes to run as background service

Step 3: Start Redis Instances

Start each Redis instance with its own config:

redis-server /etc/redis/7000/redis.conf
redis-server /etc/redis/7001/redis.conf
redis-server /etc/redis/7002/redis.conf
# Repeat for all instances

Step 4: Create the Cluster

Use redis-cli to create the cluster. You must specify the IP/hostname and port of all master and replica nodes.

redis-cli --cluster create \
  192.168.1.10:7000 192.168.1.11:7001 192.168.1.12:7002 \
  192.168.1.10:7003 192.168.1.11:7004 192.168.1.12:7005 \
  --cluster-replicas 1

This command will assign slots across masters and replicas. Confirm the prompt by typing yes.

Step 5: Verify the Cluster

Run the following command to check cluster nodes and status:

redis-cli -c -p 7000 cluster nodes

You should see nodes with their IDs, roles (master/slave), and slot assignments.

Troubleshooting Tips

Ports not open: Ensure firewall rules allow communication on all Redis ports.
Cluster creation errors: Check that all nodes can reach each other via ping/netcat and have compatible Redis versions.
Data loss concerns: Use appendonly yes in config for persistence and backups.
Timeouts: Increase cluster-node-timeout if nodes are slow to respond.

Summary Checklist

Install Redis 3.0 or higher on each machine
Configure each Redis node with cluster mode enabled
Start Redis instances on unique ports
Run redis-cli --cluster create with all node addresses
Verify cluster is healthy with cluster nodes
Configure persistence and backups to protect data

Redis Cluster provides scalable and highly available Redis databases for your applications. For more on installing specialized databases, see our guide on <a href="/