F5 Lab 1.9: Load Balancing Algorithm - Dynamic Load Balancing

After test the configuration for static load balancing round-robin and ratio (member) on the last article here, I also try configuration for dynamic load balancing using least connection (member). Least connection (member) method will compare the concurrent connections to each pool member. The pool member with least concurrent connection will preferred handle the new incoming connection. Least connection also can be compared active connection based on node.

By using the same virtual server MARKETING_WEB VS on the previous lab article then I changed the load balancing method to least connection.

After it configured, I generate some traffic from user PC1 and keep the connection active on the browser. Here below the statistic:

The request from user PC 1 is handled by Node3 with 2 active connections. Then during the connections alive, I also generate traffic from other PC user but using Apache Benchmark tools by simulating 500 requests and 50 concurrent connections.

Then the statistic for the pool is increased as the second traffic is flowing through.

From the statistic collected on the pool, it shows that more traffic is handled by Node4. It expected because of differentiation on active connection handled by the Node3 and Node4. F5 compares the active connection for both pool member and the F5 see that Node4 has least connection counts so the traffic is forwarded to Node4.

Least connection method works well for many application and it well suited if the backend servers have similar capabilities.

Reference:

• F5-Least Connection Method
• F5-Load Balancing Method Selection