1. A workload categorization method executing on a computer system for detecting roles change in a host computing device, the method comprising the step of: monitoring transactions in the host computing devices, wherein monitoring step comprises the steps of: receiving notifications of transaction executions through an instrumented interface; and logging records for corresponding ones of said notifications; categorizing said transactions according to transaction type; grouping said transactions according to said categorizing, wherein said grouping comprises measuring a magnitude of each of categorization by counting a number of transactions having a like characterization in each categorization, and wherein said grouping forms a new workload pattern; comparing said new workload pattern to a previous stored workload pattern wherein said comparing comprises comparing a transaction types and magnitude for each categorization; and determining that a role change has occurred in the host computing device if said workload patterns differ by a threshold amount.