RedisHow-ToBeginner · 3 min read

How to Set Up Redis Replication: Simple Guide

To set up Redis replication, configure a Redis server as a master and one or more as replicas by adding replicaof <master-ip> <master-port> in the replica's configuration or via the REPLICAOF command. This makes replicas copy data from the master automatically.

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Syntax

Redis replication involves a master server and one or more replica servers. The replica servers use the replicaof <master-ip> <master-port> directive in their configuration file (redis.conf) or the REPLICAOF command at runtime to start replicating data from the master.

replicaof: Tells the Redis server to become a replica of the specified master.
<master-ip>: IP address of the master Redis server.
<master-port>: Port number of the master Redis server (default is 6379).

redis

replicaof <master-ip> <master-port>

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Example

This example shows how to configure a Redis replica to replicate from a master running on IP 192.168.1.100 and port 6379. You can add this line to the replica's redis.conf file or run the command in the Redis CLI.

redis

# On replica server redis.conf
replicaof 192.168.1.100 6379

# Or in Redis CLI on replica server
> REPLICAOF 192.168.1.100 6379

Output

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Common Pitfalls

Not setting replicaof correctly: Forgetting to specify the correct master IP and port will prevent replication.
Firewall or network issues: The replica must be able to connect to the master on the specified port.
Using slaveof instead of replicaof: slaveof is deprecated; always use replicaof.
Master requiring authentication: If the master uses a password, replicas must be configured with masterauth to authenticate.

redis

## Wrong (deprecated):
slaveof 192.168.1.100 6379

## Correct:
replicaof 192.168.1.100 6379

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Quick Reference

Directive/Command	Purpose
replicaof	Set the server as a replica of the master at given IP and port
REPLICAOF	Runtime command to start replication from master
masterauth	Set password to authenticate with master if required
replicaof no one	Make the server stop replicating and become a master

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Key Takeaways

Use the replicaof directive or REPLICAOF command to configure replicas.

Ensure network connectivity between master and replicas on the Redis port.

Use masterauth if the master requires a password for replication.

Avoid deprecated slaveof; always use replicaof for replication setup.

Replicas automatically sync data from the master once configured.