Replica node failure eliminates failover capability and recovery options

PostgreSQL replica node fails due to operating system failure, hardware failure, or disk failure. Not immediately critical unless it's the only replica or serves production read traffic.

Create new replica immediately if only one exists. Take consistent backup of primary and restore to new slave node. Configure replication between new slave and primary. Update load balancer configuration or client connection strings if replica served read traffic. Investigate failed replica on separate server to determine root cause while maintaining operational replica count.