Managing Component Instances

After a component is created and deployed, you can manage component instances on the component Instance List page.

Context

For components deployed on VMs, a component instance is a running process on the VM. For components deployed in CCE clusters, a component instance is a pod, which is the minimum unit for deploying applications or services.

For components deployed on VMs:
- When Creating a Component Based on a VM or Creating a Component Using a Component Template, if the component name contains fewer than 54 characters, the component instance name can contain up to 61 characters. The instance name format is as follows:
```
{All of the component name}-{All or part of the environment name}_{Five random characters generated by the system}
```
- When Creating a Component Based on a VM or Creating a Component Using a Component Template, if the component name contains 54 characters or more, the component instance name must contain 60 characters. The instance name format is as follows:
```
{First 54 characters of the component name}_{Five random characters generated by the system}
```

For components deployed in CCE clusters:
- When Creating a Component Based on a Container Using Manual Configurations, Creating a Component Based on a Container Using YAML Configurations, or Creating a Component Using a Component Template, if you select Stateful for Workload Type and customize a workload name, the component instance name can contain up to 52 characters.
- When Creating a Component Based on a Container Using Manual Configurations, Creating a Component Based on a Container Using YAML Configurations, or Creating a Component Using a Component Template, if you select Stateless or DaemonSet for Workload Type and customize a workload name, the component instance name can contain up to 63 characters.
- When Creating a Component Based on a Container Using Manual Configurations, Creating a Component Based on a Container Using YAML Configurations, or Creating a Component Using a Component Template, if the workload name is automatically generated by the system, the component instance name can contain up to 52 characters.
- When Creating a Component by Importing a CCE Workload, the workload name is fixed to the name of the imported CCE workload.

The number of component instances deployed on a VM is the number of VMs selected during component deployment. The number of component instances deployed in a CCE cluster is the number of instances set during component deployment, that is, the number of pods.

Managing Component Instances

Log in to ServiceStage.
Use either of the following methods to go to the Instance List page.
- On the Application Management page, click the application to which the component belongs, and click the target component in Component List.
- On the Component Management page, click the target component.
If the component is created by Creating a Component by Importing a CCE Workload and is not enabled:
1. In the displayed dialog box, click OK.
2. On the Enable Component page, click Enable and wait until the component is restarted.

On the Instance List page, you can perform the following operations.

Operation	Description
Restart a single instance	If an instance of a container-deployed component is abnormal, you can delete the instance to restart it. In Instance List, locate the target instance and choose More > Delete Instance in the Operation column. In the displayed dialog box, click OK. Manually deleting an instance may cause residual resources on the node where the instance is located. You need to manually clear these resources.
View instance running monitoring information	By viewing the instance running monitoring information, you can learn about the CPU and memory usage of a single running instance. In Instance List, locate the target instance and click Monitoring in the Operation column. On the Monitoring tab, view the instance running monitoring information.
View instance running events	ServiceStage allows you to view details about events that occur during the running of a specified instance. In Instance List, locate the target instance and click Events in the Operation column. On the Events tab, view the events that occur during instance running.
View running instance containers	For container-deployed components, ServiceStage allows you to view information about the container where a specified instance runs, including the container name, running status, and mounted image. In Instance List, locate the target instance and choose More > Containers in the Operation column. On the Containers tab, view the information about the container where the instance runs.
View instance container logs	For container-deployed components, you can view component container logs to locate and rectify faults that occur during component running. In Instance List, locate the target instance and choose More > Container Logs in the Operation column. On the Container Logs tab, view the information about the container where the instance runs. Select the container where the component instance is located from the Container drop-down list. Specify Lines to configure how many rows you can view. You can view up to 100, 200, 500, 5000, or 10,000 lines. Click Download to download the logs. You can also view component container logs by referring to Viewing Container Logs.