Suspend and Resume

This section introduces how to suspend and resume the workflow in KubeVela.

Suspend the Workflow

In KubeVela, you can choose to use the vela command to manually suspend the execution of the workflow, or use a built-in special step type suspend to automatically suspend the workflow.

Suspend Manually

If you have an application in runningWorkflow state, you want to stop the execution of the workflow, you can use vela workflow suspend to stop the workflow and use vela workflow resume to continue it.

  • Suspend the application
  1. vela workflow suspend my-app

Suspend and Resume - 图1tip

Nothing will happen if you suspend an application that has already finished running workflow, which is in running status.

Use Suspend Step

Apply the following example:

  1. apiVersion: core.oam.dev/v1beta1
  2. kind: Application
  3. metadata:
  4.   name: suspend-demo
  5.   namespace: default
  6. spec:
  7.   components:
  8.   - name: comp1
  9.     type: webservice
  10.     properties:
  11.       image: crccheck/hello-world
  12.       port: 8000
  13.   - name: comp2
  14.     type: webservice
  15.     properties:
  16.       image: crccheck/hello-world
  17.       port: 8000
  18.   workflow:
  19.     steps:
  20.     - name: apply1
  21.       type: apply-component
  22.       properties:
  23.         component: comp1
  24.     - name: suspend
  25.       type: suspend
  26.     - name: apply2
  27.       type: apply-component
  28.       properties:
  29.         component: comp2

Use vela status to check the status of the Application:

  1. vela status suspend-demo

expected output

  1. About:
  3.   Name:         suspend-demo
  4.   Namespace:    default
  5.   Created at:   2022-06-27 17:36:58 +0800 CST
  6.   Status:       workflowSuspending
  8. Workflow:
  10.   mode: StepByStep
  11.   finished: false
  12.   Suspend: true
  13.   Terminated: false
  14.   Steps
  15.   - id:yj9h29uv6v
  16.     name:apply1
  17.     type:apply-component
  18.     phase:succeeded
  19.   - id:xvmda4he5e
  20.     name:suspend
  21.     type:suspend
  22.     phase:running
  24. Services:
  26.   - Name: comp1
  27.     Cluster: local  Namespace: default
  28.     Type: webservice
  29.     Healthy Ready:1/1
  30.     No trait applied

As you can see, when the first step is completed, the suspend step will be executed and this step will suspend the workflow.

Resume the Workflow

Resume Manually

Once the workflow is suspended, you can use the vela workflow resume command to manually resume the workflow.

Take the above suspended application as an example:

  1. vela workflow resume suspend-demo

After successfully continuing the workflow, view the status of the app:

  1. vela status suspend-demo

expected output

  1. About:
  3.   Name:         suspend-demo
  4.   Namespace:    default
  5.   Created at:   2022-06-27 17:36:58 +0800 CST
  6.   Status:       running
  8. Workflow:
  10.   mode: StepByStep
  11.   finished: true
  12.   Suspend: false
  13.   Terminated: false
  14.   Steps
  15.   - id:yj9h29uv6v
  16.     name:apply1
  17.     type:apply-component
  18.     phase:succeeded
  19.     message:
  20.   - id:xvmda4he5e
  21.     name:suspend
  22.     type:suspend
  23.     phase:succeeded
  24.     message:
  25.   - id:66jonaxjef
  26.     name:apply2
  27.     type:apply-component
  28.     phase:succeeded
  29.     message:
  31. Services:
  33.   - Name: comp2
  34.     Cluster: local  Namespace: default
  35.     Type: webservice
  36.     Healthy Ready:1/1
  37.     No trait applied
  39.   - Name: comp1
  40.     Cluster: local  Namespace: default
  41.     Type: webservice
  42.     Healthy Ready:1/1
  43.     No trait applied

As you can see, the workflow has continued to execute.

Terminate Manually

If you want to terminate a workflow while it is suspended, you can use the vela workflow terminate command to terminate the workflow.

  • Terminate the application workflow
  1. vela workflow terminate my-app

Suspend and Resume - 图2tip

Different from suspend, the terminated application workflow can’t be resumed, you can only restart the workflow. This means restart the workflow will execute the workflow steps from scratch while resume workflow only continue the unfinished steps.

  • Restart the application workflow
  1. vela workflow restart my-app

Suspend and Resume - 图3caution

Once application is terminated, KubeVela controller won’t reconcile the application resources. It can also be used in some cases when you want to manually operate the underlying resources, please caution the configuration drift.

Once application come into running status, it can’t be terminated or restarted.

Resume the Workflow Automatically

If you want the workflow to be continued automatically after a period of time has passed. Then, you can add a duration parameter to the suspend step. When the duration time elapses, the workflow will automatically continue execution.

Apply the following example:

  1. apiVersion: core.oam.dev/v1beta1
  2. kind: Application
  3. metadata:
  4.   name: auto-resume
  5.   namespace: default
  6. spec:
  7.   components:
  8.   - name: comp1
  9.     type: webservice
  10.     properties:
  11.       image: crccheck/hello-world
  12.       port: 8000
  13.   - name: comp2
  14.     type: webservice
  15.     properties:
  16.       image: crccheck/hello-world
  17.       port: 8000
  18.   workflow:
  19.     steps:
  20.     - name: apply1
  21.       type: apply-component
  22.       properties:
  23.         component: comp1
  24.     - name: suspend
  25.       type: suspend
  26.       properties:
  27.         duration: 5s
  28.     - name: apply2
  29.       type: apply-component
  30.       properties:
  31.         component: comp2

Use vela status to check the status of the Application:

  1. vela status auto-resume

expected output

  1. About:
  3.   Name:         auto-resume
  4.   Namespace:    default
  5.   Created at:   2022-06-27 17:57:35 +0800 CST
  6.   Status:       running
  8. Workflow:
  10.   mode: StepByStep
  11.   finished: true
  12.   Suspend: false
  13.   Terminated: false
  14.   Steps
  15.   - id:q5jhm6mgwv
  16.     name:apply1
  17.     type:apply-component
  18.     phase:succeeded
  19.     message:
  20.   - id:3xgfcp3cuj
  21.     name:suspend
  22.     type:suspend
  23.     phase:succeeded
  24.     message:
  25.   - id:zjux8ud876
  26.     name:apply2
  27.     type:apply-component
  28.     phase:succeeded
  29.     message:
  31. Services:
  33.   - Name: comp2
  34.     Cluster: local  Namespace: default
  35.     Type: webservice
  36.     Healthy Ready:1/1
  37.     No trait applied
  39.   - Name: comp1
  40.     Cluster: local  Namespace: default
  41.     Type: webservice
  42.     Healthy Ready:1/1
  43.     No trait applied

As you can see, the suspend step is automatically executed successfully after five seconds, and the workflow is executed successfully.