Redis Cluster

You are a Redis infrastructure engineer. The user wants to configure Redis Cluster for high availability and sharding across multiple nodes.

What to check first

• Ensure Redis 3.0+ is installed on all nodes (redis-server --version)
• Verify network connectivity between all planned cluster nodes on port 6379 and 16379 (cluster bus port)
• Check that each node has at least 3GB free memory and cluster-enabled is disabled in redis.conf initially

Steps

1. Edit /etc/redis/redis.conf on each node and set cluster-enabled yes, cluster-config-file nodes-<port>.conf, and cluster-node-timeout 15000
2. Start Redis on all nodes with redis-server /etc/redis/redis.conf (do NOT use --cluster-enabled flag; use config file)
3. Run redis-cli --cluster create <node1-ip>:6379 <node2-ip>:6379 <node3-ip>:6379 <node4-ip>:6379 <node5-ip>:6379 <node6-ip>:6379 --cluster-replicas 1 to initialize the cluster (3 masters + 3 replicas minimum)
4. Verify cluster status with redis-cli -h <any-node-ip> cluster info and redis-cli -h <any-node-ip> cluster nodes
5. Test failover by stopping a master node and confirming its replica is promoted via cluster info on remaining nodes
6. Configure client connection pooling to use CLUSTER NODES responses for slot-to-node mapping (use redis-py with RedisCluster, node-redis with cluster, or similar)
7. Monitor cluster health with redis-cli -h <node-ip> --stat and watch cluster_state:ok in cluster info output
8. Set cluster-migration-barrier 1 and cluster-require-full-coverage no in redis.conf for production resilience

Code

import redis
from rediscluster import RedisCluster

# Define initial cluster nodes (use any node in the cluster)
startup_nodes = [
    {"host": "192.168.1.10", "port": 6379},
    {"host": "192.168.1.11", "port": 6379},
    {"host": "192.168.1.12", "port": 6379},
]

# Create cluster connection with connection pooling
rc = RedisCluster(
    startup_nodes=startup_nodes,
    decode_responses=True,
    skip_full_coverage_check=True,
    connection_pool_kwargs={
        "max_connections": 50,
        "socket_connect_timeout": 5,
        "socket_keepalive": True,
    },
)

# Test cluster operations
try:
    # Set keys (automatically distributed across slots)
    for i in range(100):
        rc.set(

Note: this example was truncated in the source. See the GitHub repo for the latest full version.

Common Pitfalls

• Treating this skill as a one-shot solution — most workflows need iteration and verification
• Skipping the verification steps — you don't know it worked until you measure
• Applying this skill without understanding the underlying problem — read the related docs first

When NOT to Use This Skill

• When a simpler manual approach would take less than 10 minutes
• On critical production systems without testing in staging first
• When you don't have permission or authorization to make these changes

How to Verify It Worked

• Run the verification steps documented above
• Compare the output against your expected baseline
• Check logs for any warnings or errors — silent failures are the worst kind

Production Considerations

• Test in staging before deploying to production
• Have a rollback plan — every change should be reversible
• Monitor the affected systems for at least 24 hours after the change