DataWorks:Configure a DRDS node

Background information

PolarDB for Xscale (PolarDB-X), formerly called DRDS, is a distributed database service. It allows you to perform a scale-out operation to upgrade a relational database to a distributed system that supports storage and access of large amounts of data. PolarDB-X maintains the original features of relational databases, such as MySQL. For more information, see Overview.

Prerequisites

• The business process has been created.

  Data Studio performs engine-specific development operations based on business flows. Before creating a node, create a business flow first. For more information, see Create a business flow.

• A DRDS data source is added.

  You must add your PolarDB-X database to DataWorks as a DRDS data source before you can use the data source to access data in the database. For information about how to add a data source, see Add and manage data sources. For information about how to use a DRDS data source in DataWorks, see DRDS (PolarDB-X 1.0) data source.

  Note

  You can create DRDS nodes based on only DRDS data sources that are added to DataWorks in Java Database Connectivity (JDBC) connection string mode.

• 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; required for Resource Access Management (RAM) users) The RAM user used for task development has been added to the target workspace and assigned either the Development or Workspace Administrator role (which grants broad permissions—assign with caution). For more information about adding members and granting permissions, see Add members to a workspace.

Limits

This type of node is supported in the following regions: China (Hangzhou), China (Shanghai), China (Beijing), China (Shenzhen), China (Chengdu), China (Hong Kong), Singapore, Malaysia (Kuala Lumpur), Germany (Frankfurt), US (Silicon Valley), and US (Virginia).

Step 1: Create a DRDS node

1. Log on to the DataWorks console. In the target region, click Data Development and O&M > Data Development in the left-side navigation pane. Select a workspace from the drop-down list and click Go to Data Development.

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

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 editor.

Step 2: Develop a DRDS task

(Optional) Select a DRDS data source

If multiple DRDS data sources are added to your workspace, you must select one from the Select Data Source drop-down list in the upper part of the configuration tab of the node based on your business requirements. If only one DRDS data source is added to your workspace, the DRDS data source is used to develop tasks.

Develop SQL code: Simple example

In the code editor on the configuration tab of the DRDS node, write task code. Sample code:

SELECT * FROM usertablename;

Develop SQL code: Use scheduling parameters

DataWorks provides Scheduling Parameter that allow you to dynamically pass parameters to code in periodic scheduling scenarios. In a node task, you can define a variable in your code by using the ${variable_name} format. Then, assign a value to the variable in the scheduling properties > Scheduling Parameter section in the right-side navigation bar of the node editing page. For more information about the supported formats and configuration details, see Supported formats for scheduling parameters and Configure and use scheduling parameters.

Sample code:

SELECT '${var}'; -- You can assign a specific scheduling parameter to the var variable.

Step 3: Configure task scheduling

To periodically run the node task, click Scheduling on the right side of the node editing page and configure scheduling settings based on your needs. For more information, see Overview of task scheduling properties.

Step 5: Submit and publish the task

After configuring the node task, submit and publish it. Once published, the node runs periodically based on its scheduling configuration.

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

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

   In the Submission dialog box, enter a Change Description. Optionally, choose whether to require code review after submission.

   Note

   • You must configure the node’s Rerun attribute and Parent Nodes before you can submit the node.

   • Code review helps ensure code quality and prevents errors caused by unreviewed code being published directly to production. If code review is enabled, the submitted node code must be approved by reviewers before it can be published. For more information, see Code review.

If you are using a workspace in standard mode, after successfully submitting the task, click Publish in the upper-right corner of the node editing page to deploy the task to the production environment. For more information, see Publish a task.

Next steps

Task operations: After a task is committed and published, it runs periodically based on the node's configuration. You can click O&M in the top-right corner of the node editing page to go to the Operation Center and view the scheduling and running status of the scheduled task. For more information, see Managing Scheduled Tasks.