The Data Integration Service appends log events to the current workflow log when you recover the workflow instance. When the recovered workflow instance includes a restarted Mapping task, the Data Integration Service creates a mapping log.
If the workflow instance runs on a Data Integration Service grid, the recovery of the workflow instance might run on a different node than the original workflow instance. If the recovery runs on a different node and the log directory is not shared, the Data Integration Service creates a log file with the same name on the current node.