Built-in step types (Operators)

Operator (or step types)

Operators are predefined, composable step logic modules that can be used as building blocks for the pipeline.

Operator	Description	WhenReady	WhenStarting	Started(Working) When	Completes When	Notes
Sequence	Completes a series of steps in sequence	Marks first child ready	Starts the first child step	When first child is started	After the last step is completed
ParallelAnd	Run steps parallelly	Marks all children ready	Starts all children steps	Any of the children started	After all children are completed	supports dynamically adding/removing children tasks
ParellelReplica	Similar to Parallel, but all children tasks are the same configuration
Xor	Exclusive Or (Multiform)	Moves all children to `Ready` state	N/A	Any one child starts	After any child step completes	When one of the children is `Working`, request other children to pause; unpause if no one completes; Does not start proactively, requires children to be proactive
Interactive	Human input	Publishes to queue	N/A (cannot force start)	When assignment is accepted	When assignment submission is accepted
If	Performs a step only if a certain criterion is met	Checks the condition; if met, completes itself, otherwise make child `Ready`	N/A	Child is started	Condition is met or child completes
While
DoWhile

Uninitialized: Initial state
Initialized: Initialized. But is not yet allowed to start (e.g. previous step have not complete).
Ready: Allowed to start working. Inputs are ready. Steps that require human input (Interactive) may move to Working state proactively; passive steps will wait for parent step to trigger.
Working: Actively doing work
Pausing: Has been requested to pause, but not paused yet.
Paused: Work is paused. For Interactive steps, assignments are aborted.
Stopped: Step has stopped (either completed or failed). An ExecutionResult should be available.