To provide call graph data associated with business transaction snapshots, the agent starts a ten-second process snapshot whenever it starts a business transaction snapshot that is triggered by periodic collection or a diagnostic session if there is no existing process snapshot in progress for the current process. Process snapshots do not overlap. Periodic collection means that a business transaction is collected at periodic intervals, by default every ten minutes, but configurable. Diagnostic session means that either the agent has detected a pattern of possible performance issues and automatically started capturing transaction snapshots or a human has manually started a diagnostic session for the same reason.