A task error either interrupts the running workflow instance or causes the Data Integration Service to skip the task during the workflow instance run, depending on the recovery strategy.
Task errors are recoverable or nonrecoverable. Recoverable task errors are errors that you can fix without making changes to the workflow definition. Nonrecoverable task errors require that you change the workflow definition or change a parameter value in the parameter file. You can recover a workflow instance interrupted by a recoverable task error if you enabled recovery for the workflow.
Workflow tasks can use restart or skip as the recovery strategy. If the task uses restart as the recovery strategy, a task error interrupts the workflow instance. If a task uses skip as the recovery strategy, a task error causes the Data Integration Service to skip the task.
All tasks use restart as the recovery strategy except Create Cluster tasks, Mapping tasks, and Delete Cluster tasks. Create Cluster tasks always use skip as the recovery strategy. You can configure Mapping tasks and Delete Cluster tasks to use restart or skip as the recovery strategy.
Tasks can encounter the following recoverable or nonrecoverable errors:
Command task
All Command task errors are recoverable.
Human task
All Human task errors are recoverable.
When the exceptionLoadCount variable value on a Human task is less than 1, the Human task generates no task data for review. An exceptionLoadCount variable value of less than 1 does not represent a task error.
Mapping task
A Mapping task encounters a nonrecoverable error when a workflow variable or a parameter assigned to a Mapping task configuration property contains a value that is not valid. For example, a workflow string parameter with a value of 8 is assigned to the Optimizer Level configuration property.
All other Mapping task errors are recoverable.
Notification task
A Notification task encounters a recoverable error in the following situations:
When the Email Service is not available.
When the email server properties are not configured correctly.
All other Notification task errors are nonrecoverable.