When the Data Integration Service runs on a single node, the service and compute components of the Data Integration Service run on the same node. The node must have both the service and compute roles.
When the Data Integration Service runs on a grid, the service and compute components of the Data Integration Service can run on the same node or on different nodes, based on how you configure the grid and the node roles. When you configure a Data Integration Service grid to run jobs in separate remote processes, the nodes in the grid can have a combination of the service only role, the compute only role, and both the service and compute roles. Some nodes in the grid are dedicated to running the service processes while other nodes are dedicated to running mappings.