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 a running application and you want to suspend its execution, you can use vela workflow suspend to suspend the workflow.

$ vela workflow suspend my-app
Successfully suspend workflow: my-app

Use Suspend Step

Apply the following example:

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: suspend
  namespace: default
spec:
  components:
  - name: comp1
    type: webservice
    properties:
      image: crccheck/hello-world
      port: 8000
  - name: comp2
    type: webservice
    properties:
      image: crccheck/hello-world
      port: 8000
  workflow:
    steps:
    - name: apply1
      type: apply-component
      properties:
        component: comp1
    - name: suspend
      type: suspend
    - name: apply2
      type: apply-component
      properties:
        component: comp2

Use vela status to check the status of the Application:

$ vela status suspend
About:

  Name:         suspend
  Namespace:    default
  Created at:   2022-06-27 17:36:58 +0800 CST
  Status:       workflowSuspending

Workflow:

  mode: StepByStep
  finished: false
  Suspend: true
  Terminated: false
  Steps
  - id:yj9h29uv6v
    name:apply1
    type:apply-component
    phase:succeeded
    message:
  - id:xvmda4he5e
    name:suspend
    type:suspend
    phase:running
    message:

Services:

  - Name: comp1
    Cluster: local  Namespace: default
    Type: webservice
    Healthy Ready:1/1
    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:

$ vela workflow resume suspend
Successfully resume workflow: suspend

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

$ vela status suspend
About:

  Name:         suspend
  Namespace:    default
  Created at:   2022-06-27 17:36:58 +0800 CST
  Status:       running

Workflow:

  mode: StepByStep
  finished: true
  Suspend: false
  Terminated: false
  Steps
  - id:yj9h29uv6v
    name:apply1
    type:apply-component
    phase:succeeded
    message:
  - id:xvmda4he5e
    name:suspend
    type:suspend
    phase:succeeded
    message:
  - id:66jonaxjef
    name:apply2
    type:apply-component
    phase:succeeded
    message:

Services:

  - Name: comp2
    Cluster: local  Namespace: default
    Type: webservice
    Healthy Ready:1/1
    No trait applied

  - Name: comp1
    Cluster: local  Namespace: default
    Type: webservice
    Healthy Ready:1/1
    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.

$ vela workflow terminate my-app
Successfully terminate workflow: my-app

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:

apiVersion: core.oam.dev/v1beta1
kind: Application
metadata:
  name: auto-resume
  namespace: default
spec:
  components:
  - name: comp1
    type: webservice
    properties:
      image: crccheck/hello-world
      port: 8000
  - name: comp2
    type: webservice
    properties:
      image: crccheck/hello-world
      port: 8000
  workflow:
    steps:
    - name: apply1
      type: apply-component
      properties:
        component: comp1
    - name: suspend
      type: suspend
      properties:
        duration: 5s
    - name: apply2
      type: apply-component
      properties:
        component: comp2

Use vela status to check the status of the Application:

$ vela status auto-resume
About:

  Name:         auto-resume
  Namespace:    default
  Created at:   2022-06-27 17:57:35 +0800 CST
  Status:       running

Workflow:

  mode: StepByStep
  finished: true
  Suspend: false
  Terminated: false
  Steps
  - id:q5jhm6mgwv
    name:apply1
    type:apply-component
    phase:succeeded
    message:
  - id:3xgfcp3cuj
    name:suspend
    type:suspend
    phase:succeeded
    message:
  - id:zjux8ud876
    name:apply2
    type:apply-component
    phase:succeeded
    message:

Services:

  - Name: comp2
    Cluster: local  Namespace: default
    Type: webservice
    Healthy Ready:1/1
    No trait applied

  - Name: comp1
    Cluster: local  Namespace: default
    Type: webservice
    Healthy Ready:1/1
    No trait applied

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