A zero load node is a control node that supports only dry-run scheduling and does not generate data. The scheduling system does not run the zero load node but directly returns a success response when the scheduling time of the zero load node arrives. This way, the zero load node does not occupy resources, and the descendant nodes of the zero load node can be run as expected. In most cases, a zero load node serves as the start node of a workflow or the output node of multiple branch nodes. This topic describes the use scenarios of a zero load node and how to create and use a zero load node.
Prerequisites
The RAM user that you want to use is added to your workspace.
If you want to use a RAM user to develop tasks, you must add the RAM user to your workspace as a member and assign the Develop or Workspace Administrator role to the RAM user. The Workspace Administrator role has more permissions than necessary. Exercise caution when you assign the Workspace Administrator role. For more information about how to add a member and assign roles to the member, see Add workspace members and assign roles to them.
A serverless resource group is associated with your workspace. For more information, see the topics in the Use serverless resource groups directory.
A zero load node is created before you develop a task on the zero load node. For more information, see Workspace directories.
Scenarios
A zero load node is a control node that does not generate data. You do not need to configure scripts for a zero load node. You can write business introductions and other related content in the zero load node based on your business requirements. You need to only configure scheduling configurations for the zero load node based on different business scenarios.
Manage workflows in scenarios in which dependencies between nodes are complex
If you have multiple workflows, we recommend that you configure a zero load node as a start node for each workflow. This way, you can manage workflows with ease and clarify the data transmission process.
Schedule nodes that have no lineage relationship
If the final output node of a workflow has multiple branch input nodes, and the input nodes have no dependencies, you can use a zero load node as the ancestor node of the input nodes and use the root node of a workspace as the ancestor node of the zero load node. This way, you can use the root node of the workspace to schedule the zero load node and use the zero load node to schedule the input nodes. If you want to schedule all nodes in the workflow in a unified manner, you can specify the scheduling time of the zero load node. After the zero load node is scheduled, the descendant nodes can be scheduled.
Di_Log and Di_User nodes have no lineage relationship. Therefore, you cannot configure scheduling dependencies between the nodes based on lineage. In this case, you can use a zero load node named Vi_Start as the start node to schedule the descendant branch nodes that have no lineage relationship. The descendant branch nodes are run when specific conditions are met.
If you configure the root node of a workspace as the ancestor node of other nodes, the root node is not displayed in the workflow. You can view the root node of the workspace in Operation Center only after the node is committed and deployed. For more information about node O&M in Operation Center, see Perform basic O&M operations on auto triggered nodes.
Configure a zero load node
After the zero load node used as a start node is created, configure scheduling properties for the zero load node to periodically schedule the entire workflow.
After the node code and scheduling settings are configured, deploy the zero load node to the production environment. For more information, see Deploy nodes.
After the deployment is complete, go to the Auto Triggered Nodes page in Operation Center to view the auto triggered task that is deployed and perform O&M operations on the task. The node periodically runs as expected based on the scheduling settings that you configure. For more information, see Getting started with Operation Center.