第 24 章 Configuring a node placement strategy

To configure the capacity that a node provides or a resource requires, you can use utilization attributes for nodes and resources. You do this by setting a utilization variable for a resource and assigning a value to that variable to indicate what the resource requires, and then setting that same utilization variable for a node and assigning a value to that variable to indicate what that node provides.

You can name utilization attributes according to your preferences and define as many name and value pairs as your configuration needs. The values of utilization attributes must be integers.

Configuring node and resource capacity

The following example procedure configures utilization attributes for two nodes and then specifies the same utilization attributes that three different resources require. A node is considered eligible for a resource if it has sufficient free capacity to satisfy the resource’s requirements, as defined by the utilization attributes.

Displaying node utilization as pcs commands

You can export node utilization as a series of pcs commands by using the --output-format=cmd option. This is useful for scripting, automation, or replicating the same configuration on a different system.

Configuring placement strategy

After you have configured the capacities your nodes provide and the capacities your resources require, you need to set the placement-strategy cluster property, otherwise the capacity configurations have no effect.

Four values are available for the placement-strategy cluster property:

The following example command sets the value of placement-strategy to balanced. After running this command, Pacemaker will ensure the load from your resources will be distributed evenly throughout the cluster, without the need for complicated sets of colocation constraints.

# pcs property set placement-strategy=balanced