If a host on which your Elastic Compute Service (ECS) instance resides has potential risks or fails, Alibaba Cloud sends a system event to notify you of the situation. Then, you can handle the event. When you handle the event, the system takes the default maintenance action to restart the instance. If you do not want the instance to be automatically restarted, you can change the maintenance action for the instance by modifying its maintenance attribute.

Background information

Instance maintenance attributes specify the default actions to take on ECS instances after unexpected or scheduled O&M events occur for the instances. You can define the default maintenance action for an instance by modifying its maintenance attribute. For example, you can configure whether to automatically restart or stop an instance in case of an unexpected O&M event. The following table describes the maintenance attributes supported by instances.
Note You can modify instance maintenance attributes but the new maintenance attributes do not affect ongoing operations. For example, if you modify the maintenance attribute of an instance that is being automatically restarted, the new maintenance attribute cannot stop the restart operation or change it into a different operation.
Instance maintenance attribute System event Supported instance Description
Automatically Restart (Default)
  • SystemMaintenance.Reboot
  • SystemFailure.Reboot
 All instances that support system events. Restores the instance to the state that it was in before the O&M task related to a system event is executed.
  • If the instance was in the Running state before the O&M task is executed, the instance is automatically restarted to continue providing services.
  • If the instance was in the Stopped state before the O&M task is executed, the instance remains in the Stopped state.
Stop
  • SystemMaintenance.Stop
  • SystemFailure.Stop
 All instances that support system events. Puts the instance into the Stopped state. This maintenance attribute is applicable to scenarios in which failovers or switchovers are performed at the application layer for disaster recovery purposes to prevent conflicts between multiple nodes in service.
Automatically Re-deploy
  • SystemMaintenance.Redeploy
  • SystemFailure.Redeploy
 Instances that depend on host hardware, such as instances that have local disks attached or that support Software Guard Extensions (SGX) encrypted computing. For information about the instance families of such instances, see Instance family.
Note After an instance is redeployed, the data on its local disks is deleted and SGX is reset.
Redeploys the instance to another host to continue providing services.
To make better use of instance maintenance attributes, we recommend that you use multiple methods to improve fault tolerance for your business and reduce the impacts of O&M. Examples:
  • Configure core applications such as SAP HANA to automatically start on system startup. This helps prevent business interruptions.
  • Enable the automatic reconnection feature for your applications. For example, allow applications to automatically connect to MySQL, SQL Server, or Apache Tomcat.
  • Deploy multiple ECS instances in a cluster if you use Server Load Balancer (SLB). When an ECS instance is being automatically restarted, other ECS instances can continue to provide access to your services.
  • Back up data on local disks on a regular basis to ensure that redundant data copies are available for you to redeploy instances.

Procedure

  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Instances & Images > Instances.
  3. In the top navigation bar, select a region.
  4. Find the instance and use one of the following methods to modify its maintenance attribute:
    • Method 1: Choose More > Operations and Troubleshooting > Modify Instance Maintenance Attribute in the Actions column corresponding to the instance.
    • Method 2: Click the ID of the instance to go to the Instance Details page. In the upper-right corner of the tab, choose All Operations > Operations and Troubleshooting > Modify Instance Maintenance Attribute.
  5. In the Modify Instance Maintenance Attribute dialog box, set the Maintenance Action parameter and click OK.
    • If the instance has only cloud disks attached, you can select one of the following options for Maintenance Action:
      • Automatically Restart
      • Stop
    • If the instance has local disks attached, you can select one of the following options for Maintenance Action:
      • Automatically Restart
      • Stop
      • Automatically Re-deploy
  6. In the Other Information section of the Instance Details tab, confirm the new Maintenance Attribute settings.
    View the Maintenance Attribute settings