DM node

Background

Dameng (DM) is an online transaction processing (OLTP) database that integrates with business systems. It combines the advantages of distributed and elastic computing with cloud computing, offering flexibility, ease of use, reliability, and high security. For more information, visit the official DM website.

Prerequisites

• A workflow is created.

  You must create a workflow before you create a node. For more information, see Create a workflow.

• A DM data source is created.

  To access your DM database, you must first add it as a DM data source in DataWorks. To create a data source, see Manage data sources. For information about how to use a DM data source in DataWorks, see DM data source.

  Note

  DM nodes support only DM data sources that are created by using a JDBC connection string.

• A network connection is established between your data source and a resource group.

  You must make sure that the desired data source is connected to the resource group that you want to use. For more information about how to configure network connectivity, see Establish a network connection between a resource group and a data source.

• (Optional) If you use a RAM user for task development, the RAM user must be added to the workspace and granted the Development or Workspace Administrator role. The Workspace Administrator role provides extensive permissions. Grant this role with caution. For more information about how to add members to a workspace and grant roles to the members, see Add members to a workspace.

Limits

Supported regions: China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Shenzhen), China (Chengdu), China (Hong Kong), Singapore, Malaysia (Kuala Lumpur), Germany (Frankfurt), US (Silicon Valley), and US (Virginia).

Step 1: Create a DM node

1. Go to the DataStudio page.

   Log on to the DataWorks console. In the top navigation bar, select the desired region. In the left-side navigation pane, choose Data Development and O&M > Data Development. On the page that appears, select the desired workspace from the drop-down list and click Go to Data Development.

2. Right-click the target workflow and choose Create Node > Database > DM.

3. In the Create Node dialog box, enter a Name for the node and click OK. After the node is created, you can develop and configure the task in the node.

Step 2: Develop a DM task

(Optional) Select a DM data source

If your workspace has multiple DM data sources, you must select the appropriate one on the node's editor page. If only one DM data source is created, it is used for development by default.

Develop SQL code: Simple example

In the code editor of the DM node, write the task code. The following code provides an example.

SELECT * FROM usertablename;

Develop SQL code: Use scheduling parameters

DataWorks provides Scheduling Parameter that let you dynamically pass values to your code in periodic scheduling scenarios. You can define variables in your task code by using the ${variable_name} format and then assign a value to the variable in the right-side navigation pane under Properties > Scheduling Parameter. For more information about the supported formats and configuration details, see Supported formats for scheduling parameters and Configure and use scheduling parameters.

The following code provides an example.

SELECT '${var}'; -- You can use this with a scheduling parameter.

Step 3: Configure task scheduling

If you need to run the node task periodically, click the scheduling properties tab in the right-side navigation pane of the node editor page and configure scheduling properties for the task based on your business requirements. For more information, see Overview of task scheduling properties.

Step 4: Debug the task

To debug the task and check whether it runs as expected:

1. (Optional) Select a resource group for scheduling and specify values for custom parameters.

   • Click the icon in the toolbar. In the Parameter dialog box, select the resource group for scheduling that you want to use for debugging.

   • If your task code uses scheduling parameters, you can specify values for them for debugging. For more information about how to specify parameter values, see Debug a task.

2. Save and run the task code.

   Click the icon in the toolbar to save the task code and click the icon to run the task.

3. (Optional) Perform smoke testing.

   To check if the scheduled task runs as expected in the development environment, you can perform smoke testing when you commit the node or after it is committed. For more information, see Perform smoke testing.

Step 5: Commit and deploy the task

After you configure the node task, you must commit and deploy it. Once deployed, the node runs on a schedule based on its scheduling properties.

1. Click the icon in the toolbar to save the node.

2. Click the icon in the toolbar to commit the node task.

   In the Submission dialog box, enter a Change Description. You can also select whether to perform a code review after you commit the node.

   Note

   • Before you can commit the node, you must specify the Rerun attribute property and Parent Nodes for the node.

   • Code review helps ensure code quality and prevents task errors that may result from deploying incorrect code to the production environment without being reviewed. If you enable code review, the submitted node code can be deployed only after reviewers approve it. For more information, see Code review.

If you use a workspace in standard mode, you must click Deploy in the upper-right corner of the node editor page after you commit the task. This operation deploys the task to the production environment. For more information, see Deploy tasks.

What's next

After the task is published, it runs on a recurring schedule based on the node's configuration. Click O&M in the upper-right corner of the node configuration tab to go to Operation Center, where you can view the scheduling and running status of the task. For more information, see Manage recurring tasks.