When you encounter the MASTER_TIMEOUT error in Redis, indicating that a replica has not been able to communicate with its master for a certain period, you can take the following immediate actions for investigation:
ping command to check the network connectivity to the master's IP address.ping <master_ip_address>
tail -f /var/log/redis/redis-server.log
INFO replication command on both the master and replica instances to check their status. This command will show you the state of replication and if the replica is connected to the master.redis-cli -h <host> -p <port> INFO replication
repl-timeout setting on the replica is not too low. It's possible that network latency or spikes in traffic are causing the timeout. You can check this setting with:redis-cli -h <replica_host> -p <replica_port> CONFIG GET repl-timeout
top, htop, netstat, or tools like iftop or nmon for real-time monitoring.redis-cli --latency command to monitor latency in real-time between the replica and the master. This can help identify if there are significant network delays affecting communication.redis-cli -h <master_host> -p <master_port> --latency
Following these steps should help you identify the root cause of the MASTER_TIMEOUT error.
(Perfect for DevOps & SREs)
(Perfect for DevOps & SREs)



