Provided are a computer program product, system, and method for modifying an assignment of nodes to roles in a computing environment. There are a plurality of resource thresholds for each of a plurality of roles, wherein each role defines a type of operations and node resource usage for the nodes, and a measurement of node resource usage for the nodes. For at least one of the node, operations are performed comprising: determining at least one of the roles assigned to the node; determining a role resource threshold for each role assigned to the node; determining whether the measured node resource usage at the node exceeds the determined role resource thresholds for each role assigned to the node, wherein the role having the determined resource threshold exceeded by the node resource usage comprises a role to adjust; and determining a modification of the assignment of nodes to the role to adjust.