Data Management:Configure a dependency check node for a task flow

Scenarios

• Inter-task flow dependency: Task Flow A runs only after Task Flow B succeeds.

  For example, Task Flow A runs at 02:00 every Monday to train a recommendation model. Task Flow A runs on top of the business data of the last week (Monday to Sunday) that is generated by Task Flow B. Hence, Task Flow A is dependent on Task Flow B.

• Self-dependency: Task Flow A runs only after its previous cycle is complete.

  For example, Task Flow A performs data cleansing. It can run only after the previous instance of Task Flow A is complete.

Usage notes

Procedure

1. Log on to the DMS console V5.0.
2. In the top navigation bar, click DTS. In the left-side navigation pane, choose Data Development > Task Orchestration.

3. Click the name of the task flow that you want to manage to go to the details page of the task flow.

   For more information about how to create a task flow, see Overview.

4. In the Task Type list on the left side of the canvas, drag the Check for Task Flow Dependency node to the blank area on the canvas.

5. Double-click the Check for Task Flow Dependency node.

6. On the configuration page of the Check for Task Flow Dependency node, configure the following parameters.

   Parameter	Description
   Task Flow	The task flow for which you want to configure a dependency check node. You can search for and select the task flow in the Task Flow field. Note If you select the current task flow, the task flow depends on the result of its previous cycle. If you select a different task flow, the current task flow depends on the result of the selected task flow.
   Dependency Object	The type of the dependency object. Valid values: Task Flow: The current task flow depends on another task flow. Single Node: The current task flow depends on an existing node in the task flow.
   Dependency Settings	The time settings of the dependency check. The settings include Start Time Offset and End Time Offset. By default, the start time and end time are offset based on the time in point when the task is executed. For an auto triggered task flow, the business time is calculated based on the scheduled execution time of the task flow. For a manually triggered task flow, the business time is calculated based on the time when the task flow is manually triggered. Dependency configuration examples: Example 1: Task Flow A, which is scheduled to start daily at 07:00, depends on the last scheduled cycle of Task Flow B, which is scheduled to start daily at 07:00. In the dependency check configuration, the start time offset of Task Flow A remains at 07:00, and its end time offset increases by 1 day. Note The last scheduled cycle ends when the last execution of a task flow is complete. For more information about scheduled execution time, see the "Configure scheduling properties for the task flow" section of the Configure a task flow topic. Example 2: Task Flow A, which is scheduled to start daily at 08:00, depends on the last scheduled cycle of Task Flow B, which is scheduled to start daily at 07:00. In the dependency check configuration, the start time offset of Task Flow A remains at 08:00, and its end time offset increases by 1 day and decreases by 1 hour. Example 3: Task Flow A, which is scheduled to start daily at 08:10, depends on the last scheduled cycle of Task Flow B, which is scheduled to start daily at 07:00. In the dependency check configuration, the start time offset of Task Flow A remains at 08:10, and its end time offset increases by 1 day and decreases by 1 hour and 10 minutes. Note In the upper part of the configuration page, click Preview. In the Preview Time dialog box, check whether the time values for the task flow are configured as expected and whether they ensure a successful run of the node.
   Check Policy for Database Instances	The check policy for the task flow. Valid values: Last Round Succeeded: The task flow passes the dependency check after the successful run of the last node that the current task flow depends on. All Round Succeeded: The task flow passes the dependency check only after the successful run of all the nodes that the current task flow depends on. Specified Round Succeeded: The task flow passes the dependency check after the successful run of the specified node that the current task flow depends on. Note For a manually triggered task flow, only manually triggered nodes are checked. For an auto triggered task flow, only auto triggered nodes are checked. For example, Task Flow A was manually triggered and was never automatically triggered. If you perform a dependency check on Task Flow A, the test run succeeds, but Task Flow A fails to be automatically triggered.
   Check Type	The type of the expected check time, including the start time and end time, of the task flow. Valid values: Run At: The start time and end time are offset based on the time in point when the task is executed. Business Date: The start time and end time are offset based on the bizdate time variable. The bizdate time variable specifies the day before the time in point when the task is executed.

7. Click Try Run.

   • If status SUCCEEDED appears in the last line of the execution log, the test run is successful.

   • If status FAILED appears in the last line of the execution log, the test run fails.

     Note

     If the test run fails, you can view the node on which the failure occurs and the reason for the failure in the execution log. Then, you can modify the configuration of the node and try again.