SafeKit: All-in-One Linux Load Balancing & High Availability Software

The SafeKit cluster in farm mode is designed for high availability and scalability of services. The configuration focuses on distributing incoming traffic across both nodes simultaneously:

• Load Balanced Services (Macros tab): Define the specific application services (e.g., Apache, IIS, Nginx) to be kept active on all nodes.
• Heartbeat network(s): Communication path(s) used to detect if a node has left the farm, triggering an immediate redistribution of the load.
• Virtual IP (Farm VIP): Unlike a mirror cluster, the Farm VIP is shared between nodes using kernel filtering algorithm to distribute network traffic.
• Load Balancing Rules: Define the traffic distribution policy based on the source IP address or port.
• Checkers: Monitor the application's health and trigger automatic restart if a process failure is detected.

Monitoring a cluster in farm mode provides visibility into the Active-Active nature of the infrastructure, where all nodes contribute to the application's performance (showing 2 nodes in this example):

• UP State (50% on 2 nodes): In a healthy farm, both nodes are in the "UP" (50%) state, meaning they are both actively receiving and processing client requests via the shared Virtual IP.
• Automatic Re-balancing: If one node fails, the console visually shows the remaining node taking 100% of the traffic. There is no "failover" delay, as the surviving node is already active (aside from a detection time of a few seconds).
• Node Insertion: When a repaired node is restarted, it transitions from "STOP" to "UP" and automatically starts receiving its portion of the load without administrator intervention.
• No Data Sync: Note that in a farm-mode cluster, there is no "Orange" resynchronization state, as nodes are expected to be stateless or share a backend database (which can be protected separately in a mirror cluster).

Beyond simple status icons, the interface provides one-click node management, allowing you to manually stop or start a node for planned maintenance while the shared Virtual IP automatically redistributes traffic without interrupting user activity.