Redis Cluster Bus
What is Port 16379?
Port 16379 is the default Redis Cluster bus port, used for node-to-node communication in a Redis Cluster deployment. Redis Cluster uses this port (always the data port + 10000, so 6379 + 10000 = 16379) for binary protocol communication between nodes. The cluster bus handles failure detection through gossip, configuration updates, failover authorization, and data migration between slots. When Redis Cluster reshards data or promotes a replica to master, the coordination happens over the cluster bus. Every node in a Redis Cluster must be able to reach every other node on both the client port (6379) and the cluster bus port (16379).
Common Uses
- Redis Cluster node-to-node communication
- Cluster gossip and failure detection
- Slot migration during resharding
- Failover coordination between nodes
Technical Details
Copy-paste commands to check port 16379 (Redis Cluster Bus) from your terminal
Test connectivity
nc -zv example.com 16379
curl -v --max-time 5 http://example.com:16379/
telnet example.com 16379
nmap -p 16379 -sV example.com
(echo > /dev/tcp/example.com/16379) 2>/dev/null && echo "open" || echo "closed"
Open port in firewall
sudo ufw allow 16379/tcp
sudo iptables -A INPUT -p tcp --dport 16379 -j ACCEPT
sudo firewall-cmd --permanent --add-port=16379/tcp && sudo firewall-cmd --reload
Security Considerations
Enable TLS for cluster bus communication in Redis 6+. Restrict port 16379 to Redis cluster member IPs only. Use the same authentication credentials as the client port. Monitor for unauthorized cluster join attempts.
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