Using the "WLBS QUERY" Command to Determine the State of an WLBS/NLB Cluster

The wlbs query command displays the current state of a Windows Load Balancing Service (WLBS)/Network Load Balancing (NLB) cluster. Additionally, it provides host priority information.

The WLBS/NLB control program (Wlbs.exe) provides several cluster control commands. The correct syntax is: One of these commands is the query command. This command displays the current state of the cluster. It also provides host priority information. Possible cluster states include:

• Unknown: The responding host has not started load balancing operations or cannot determine the cluster's state.
• Converging: The cluster is attempting to converge to a consistent state. Should nodes remain in this state for a prolonged period of time, it usually indicates a problem with cluster configuration parameters. Parameters for each node can be displayed using the wlbs display command (this must be run on each node). Printing the results of this command may assist in determining the problem. Also, checking the system logs on each node may provide clues to a problem with the cluster and/or node.
• Draining: The cluster has converged, and the responding host is "draining" active connections prior to stopping load balancing operations.
  • Drain: A program that disables new traffic handling for the rule whose port range contains the specified port. All ports specified by the port rule are affected.
  • Drainstop: A tool that disables all new traffic handling on the specified hosts. The hosts then enter the draining mode to complete existing connections. While draining, hosts remain in the cluster and stop their cluster operations when there are no more active connections. You can terminate draining mode by explicitly stopping the cluster mode with the stop command or by restarting new traffic handling with the start command. To drain connections from a specific port, use the drain command.
• Converged as DEFAULT: The cluster has converged, and the responding host is the current DEFAULT (the highest priority host without a drainstop command in progress. The DEFAULT host handles all traffic for all TCP/UDP ports not specifically defined by port rules.
• Converged: The cluster has converged and the responding host is not the DEFAULT host.

A wlbs query command run on the DEFAULT host in a two-node cluster generates output similar to: A wlbs query command run on another host in a two-node cluster generates output similar to: Using the wlbs query command can help focus troubleshooting steps on a WLBS/NLB cluster. If the result of a wlbs query command shows all cluster nodes converging, troubleshooting can probably continue in other areas.