dolphinscheduler0701/docs/docs/en/guide/task/sub-process.md

SubProcess Node

Overview

The sub-process node is to execute an external workflow definition as a task node.

Create Task

• Click Project Management-> Project Name -> Workflow Definition, and click the Create Workflow button to enter the DAG editing page.
• Drag from the toolbar task node to canvas to create a new SubProcess task.

Task Parameter

Parameter	Description
Node name	Unique name of node in workflow definition.
Run flag	Identifies whether this node schedules normally.
Description	Describe the function of the node.
Task priority	When the number of worker threads is insufficient, execute in the order of priority from high to low, and tasks with the same priority will execute in a first-in first-out order.
Worker group	Assign tasks to the machines of the worker group to execute. If Default is selected, randomly select a worker machine for execution.
Task group name	The group in Resources, if not configured, it will not be used.
Environment Name	Configure the environment name in which run the script.
Timeout alarm	Check the timeout alarm and timeout failure. When the task runs exceed the "timeout", an alarm email will send and the task execution will fail.
Child node	It is the workflow definition of the selected sub-process. Enter the child node in the upper right corner to jump to the workflow definition of the selected sub-process.
Pre task	Selecting a predecessor task for the current task, will set the selected predecessor task as upstream of the current task.

Task Example

This example simulates a common task type, here we use a child node task to recall the Shell to print out "hello". This means executing a shell task as a child node.

Create a Shell task

Create a shell task to print "hello" and define the workflow as test_dag01.

Create the Sub_process task

To use the sub_process, you need to create the sub-node task, which is the workflow test_dag01 we created in the first step. After that, as shown in the diagram below, select the corresponding sub-node in position ⑤.

After creating the sub_process, create a corresponding shell task for printing "world" and link both together. Save the current workflow and run it to get the expected result.

Note

When using sub_process to recall a sub-node task, you need to ensure that the defined sub-node is online status, otherwise, the sub_process workflow will not work properly.