Tenable Nessus Agents may become unevenly distributed across child nodes for various reasons: a child node or multiple child nodes may be temporarily unavailable, disabled, deleted, or recently added. Events such as these negatively impact the cluster's performance. When the imbalance passes a certain threshold, Tenable Nessus Manager gives you the option to rebalance child nodes. This threshold is passed when one or both of the following criteria are met:
10% of your agents are not ideally distributed, based on your nodes' ideal capacity.
A single node has at least 5% more agents than the node's ideal capacity.
Your organization has four nodes and 100 linked agents. To evenly distribute linked agents across four nodes, Tenable Nessus Manager should assign each node 25% of the total linked agents which, in this case, would be 25 linked agents per node.
Tenable Nessus Manager gives you the option to rebalance child nodes if either:
Tenable Nessus Manager can redistribute 10% or more of your linked agents (in this example, 10 linked agents or more) for better results. For example, if two of your nodes have 20 linked agents and two of your nodes have 30 linked agents, Tenable Nessus Manager would allow you to rebalance the nodes to reach the ideal 25-25-25-25 distribution.
One of your nodes reaches 30% of its capacity (in this example, ~33 linked agents)
When you rebalance child nodes, Tenable Nessus Agents get redistributed more evenly across child nodes
To rebalance child nodes:
In the top navigation bar, click Sensors.
The Linked Agents page appears. By default, Linked Agents is selected in the left navigation menu and the Linked Agents tab is active.
In the left navigation bar, click Agent Clustering.
The Cluster Groups page appears.
- In the cluster groups table, click the row of a cluster group.
In the upper-right corner of the page, click Rebalance Nodes.
Tenable Nessus Manager rebalances the Tenable Nessus Agent distribution across child nodes.