In this scenario, each backend node (server) hosts multiple services and is referenced by multiple pools and virtual servers. The goal is to ensure an equal number of total connections per backend server, regardless of how many pool members (services/ports) exist on that server.
According to the BIG-IP Administration: Data Plane Configuration documentation:
Least Connections (node) tracks the total number of active connections to a node across all pool members and services.
This algorithm ensures load distribution is balanced at the server level, not just at the individual service (member) level.
It is specifically recommended when:
Multiple pool members exist on the same backend server
Multiple virtual servers reference the same backend servers
Why the other options are incorrect:
B. Predictive (member)Predictive algorithms are advanced and traffic-pattern based, but they operate at the member level and do not guarantee equal connections per server.
C. Least Connections (member)This balances connections per pool member, which can overload a server hosting multiple members while still appearing “balanced” per member.
D. Predictive (node)Although node-aware, predictive algorithms are less deterministic and not the best choice when strict equality of connections is required.
Correct Resolution:
Using Least Connections (node) ensures that each backend server carries an equal connection load across all services and pools.