Keepalived VIP Loss Due to systemd-networkd Restart

In a test environment using Ubuntu 18.04 with Keepalived v1.3.9 (installed via apt-get) in a Master-Backup configuration alongside Nginx, an unexpected loss of the Virtual IP (VIP) on the Master node was observed. The service became unreachable, yet no failover occurred—both nodes showed no Keepalived transition logs. Restarting Keepalived on t ...

Posted on Sun, 21 Jun 2026 17:06:19 +0000 by mlla2

Redis Master-Slave Replication Implementation

Redis Replication Fundamentals Redis replication enables automatic data synchronization from a primary node (master) to replica nodes (slaves). The master handles write operations while replicas serve read requests. Replicatino Mechanism Replicas initiate synchronization by sending a SYNC command to the master The master starts a background sa ...

Posted on Tue, 09 Jun 2026 17:45:48 +0000 by mysqlnewjack

Deploying Redis Sentinel for High Availability

Redis offers three main clustering solutions: Redis Cluster, master/slave replication, and Sentinel mode for automatic failover and fault recovery. Sentinel Mode Overview Sentinel mode builds upon the master/slave replication model by introducing monitoring agents that automatically handle failures. Traditional master/slave setups require manua ...

Posted on Sun, 17 May 2026 03:11:19 +0000 by koen