This topic summarizes the system events supported by Elastic Compute Service (ECS) and provides suggestions on how to handle these events.

Note An event type of Undefined indicates that ECS events are not displayed in the ECS console and cannot be handled by using the ECS console or by calling API operations. Example: the Instance:StateChange event.

Scheduled O&M events

Event description ECS event type Event severity CloudMonitor event Time when a system event is triggered Handling suggestion for you
Scheduled instance restart due to system maintenance SystemMaintenance.Reboot Critical
  • Instance:SystemMaintenance.Reboot:Inquiring
  • Instance:SystemMaintenance.Reboot:Scheduled
  • Instance:SystemMaintenance.Reboot:Executing
  • Instance:SystemMaintenance.Reboot:Executed
  • Instance:SystemMaintenance.Reboot:Avoided
  • Instance:SystemMaintenance.Reboot:Failed
  • Instance:SystemMaintenance.Reboot:Canceled
This system event is triggered 24 or 48 hours before the scheduled time of system maintenance. We recommend that you take one of the following actions in response to the event:
Note You can modify the maintenance attributes of the instance to specify the default action to take when the instance encounters a maintenance event. For more information, see Instance maintenance attributes.
Scheduled instance stop due to system maintenance SystemMaintenance.Stop Critical
  • Instance:SystemMaintenance.Stop:Scheduled
  • Instance:SystemMaintenance.Stop:Executing
  • Instance:SystemMaintenance.Stop:Executed
  • Instance:SystemMaintenance.Stop:Avoided
  • Instance:SystemMaintenance.Stop:Failed
  • Instance:SystemMaintenance.Stop:Canceled
This system event is triggered 24 or 48 hours before the scheduled time of system maintenance. We recommend that you take one of the following actions in response to the event:
  • Redeploy the instance. For more information, see Redeploy an instance equipped with local disks.
  • Wait for the instance to be automatically stopped and then perform instance operations such as redeployment based on your business requirements.
Note You can modify the maintenance attributes of the instance to specify the default action to take when the instance encounters a maintenance event. For more information, see Instance maintenance attributes.
Scheduled instance redeployment due to system maintenance SystemMaintenance.Redeploy Critical
  • Instance:SystemMaintenance.Redeploy:Inquiring
  • Instance:SystemMaintenance.Redeploy:Scheduled
  • Instance:SystemMaintenance.Redeploy:Executing
  • Instance:SystemMaintenance.Redeploy:Executed
  • Instance:SystemMaintenance.Redeploy:Avoided
  • Instance:SystemMaintenance.Redeploy:Canceled
This system event is triggered 24 or 48 hours before the scheduled time of system maintenance.
Note Only instances that depend on host hardware support this type of event, such as instances that use local disks or support Software Guard Extensions (SGX) encrypted computing.
We recommend that you make preparations such as modifying the /etc/fstab configuration file and backing up data, and then take one of the following actions in response to the event:
Note You can modify the maintenance attributes of the instance to specify the default action to take when the instance encounters a maintenance event. For more information, see Instance maintenance attributes.
Isolation of damaged local disks due to system maintenance SystemMaintenance.IsolateErrorDisk Critical
  • Instance:SystemMaintenance.IsolateErrorDisk:Inquiring
  • Instance:SystemMaintenance.IsolateErrorDisk:Executing
  • Instance:SystemMaintenance.IsolateErrorDisk:Executed
  • Instance:SystemMaintenance.IsolateErrorDisk:Avoided
  • Instance:SystemMaintenance.IsolateErrorDisk:Failed
  • Instance:SystemMaintenance.IsolateErrorDisk:Canceled
This system event is triggered when a local disk is damaged. We recommend that you make preparations such as modifying the /etc/fstab configuration file and backing up data, and then select an appropriate point in time to authorize the damaged disk to be isolated. Then, the local disk is isolated online without the need to restart its associated instance.
Note For more information, see the "Scenario ③" section in O&M scenarios and system events for instances equipped with local disks.
Re-initialization of damaged local disks due to system maintenance SystemMaintenance.ReInitErrorDisk Critical
  • Instance:SystemMaintenance.ReInitErrorDisk:Inquiring
  • Instance:SystemMaintenance.ReInitErrorDisk:Executing
  • Instance:SystemMaintenance.ReInitErrorDisk:Executed
  • Instance:SystemMaintenance.ReInitErrorDisk:Avoided
  • Instance:SystemMaintenance.ReInitErrorDisk:Failed
  • Instance:SystemMaintenance.ReInitErrorDisk:Canceled
This system event is triggered immediately after Alibaba Cloud replaces a damaged local disk of the host where an instance equipped with local disks resides. Typically, the event is triggered within five business days after you authorize the damaged disk to be isolated. We recommend that you select an appropriate point in time to authorize the local disk to be restored. Then, the local disk is restored online without the need to restart its associated instance.
Note For more information, see the "Scenario ③" section in O&M scenarios and system events for instances equipped with local disks.
Isolation of damaged local disks and instance restart due to system maintenance SystemMaintenance.RebootAndIsolateErrorDisk Critical
  • Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Inquiring
  • Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Executing
  • Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Executed
  • Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Avoided
  • Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Canceled
This system event is triggered when a damaged local disk cannot be isolated online. We recommend that you select an appropriate point in time to authorize the damaged disk to be isolated and restart the associated instance after the disk is isolated. In this case, the local disk is isolated offline, so you must restart its associated instance for the isolation operation to take effect.
Note For more information, see the "Scenario ③" section in O&M scenarios and system events for instances equipped with local disks.
Re-initialization of damaged local disks and instance restart due to system maintenance SystemMaintenance.RebootAndReInitErrorDisk Critical
  • Instance:SystemMaintenance.RebootAndReInitErrorDisk:Inquiring
  • Instance:SystemMaintenance.RebootAndReInitErrorDisk:Executing
  • Instance:SystemMaintenance.RebootAndReInitErrorDisk:Executed
  • Instance:SystemMaintenance.RebootAndReInitErrorDisk:Avoided
  • Instance:SystemMaintenance.RebootAndReInitErrorDisk:Canceled
This system event is triggered when a damaged local disk cannot be restored online. We recommend that you select an appropriate point in time to authorize the local disk to be restored and restart the associated instance after the disk is restored. In this case, the local disk is restored offline, so you must restart its associated instance for the restoration operation to take effect.
Note For more information, see the "Scenario ③" section in O&M scenarios and system events for instances equipped with local disks.

Unexpected O&M events

Event description ECS event type Event severity CloudMonitor event Time when a system event is triggered Handling suggestion for you
Instance restart due to a system error SystemFailure.Reboot Critical
  • Instance:SystemFailure.Reboot:Executing
  • Instance:SystemFailure.Reboot:Executed
  • Instance:SystemFailure.Reboot:Failed
This system event is triggered when an instance is restarted due to a system error. We recommend that you wait for the instance to be automatically restarted and then check whether the instances and applications continue to work as expected.
Note You can modify the maintenance attributes of the instance to specify the default action to take when the instance encounters a maintenance event. For more information, see Instance maintenance attributes.
Instance restart due to an instance error InstanceFailure.Reboot Critical
  • Instance:InstanceFailure.Reboot:Executing
  • Instance:InstanceFailure.Reboot:Executed
This system event is triggered when an instance is restarted due to an instance error. We recommend that you wait for the instance to be automatically restarted and then check whether the instances and applications continue to work as expected. You can troubleshoot and prevent the error based on the system logs and screenshots of the instance. For more information, see System logs and screenshots.
Instance stop due to a system error SystemFailure.Stop Critical
  • Instance:SystemFailure.Stop:Executing
  • Instance:SystemFailure.Stop:Executed
This system event is triggered when an instance is stopped due to a system error. We recommend that you wait for the instance to be automatically stopped.
Note You can modify the maintenance attributes of the instance to specify the default action to take when the instance encounters a maintenance event. For more information, see Instance maintenance attributes.
Instance redeployment due to a system error SystemFailure.Redeploy Critical
  • Instance:SystemFailure.Redeploy:Inquiring
  • Instance:SystemFailure.Redeploy:Scheduled
  • Instance:SystemFailure.Redeploy:Executing
  • Instance:SystemFailure.Redeploy:Executed
  • Instance:SystemFailure.Redeploy:Avoided
  • Instance:SystemFailure.Redeploy:Canceled
This system event is triggered when a system error occurs and makes it necessary to redeploy an instance that is equipped with local disks.
Note Only instances that depend on host hardware support this type of event, such as instances that are equipped with local disks or support SGX encrypted computing.
We recommend that you make preparations such as modifying the /etc/fstab configuration file and backing up data, and then take one of the following actions in response to the event:
Note You can modify the maintenance attributes of the instance to specify the default action to take when the instance encounters a maintenance event. For more information, see Instance maintenance attributes.
Instance release due to a creation failure SystemFailure.Delete Critical
  • Instance:SystemFailure.Delete:Executing
  • Instance:SystemFailure.Delete:Executed
This system event is triggered when an instance cannot be created after the order to create the instance is placed. We recommend that you wait for the instance to be automatically released. Typically, an instance is automatically released within 5 minutes when the instance cannot be created.
Note If you have paid for the order, the payment is refunded after the instance is released.
To ensure that instances can be created, we recommend that you take the following actions:
  • Before you create ECS instances in a region and zone, query ECS resource availability and the number of idle private IP addresses in the CIDR block associated with a specified vSwitch in the region and zone. For example, you can call the DescribeAvailableResource operation to query resources in a zone.
  • Use Auto Provisioning or Auto Scaling to flexibly deliver instances from larger resource pools.
Damage alert generated for local disks ErrorDetected Critical
  • Disk:ErrorDetected:Executing
  • Disk:ErrorDetected:Executed
This system event is triggered when a local disk is damaged. We recommend that you make preparations such as modifying the /etc/fstab configuration file and backing up data, and then have the damaged local disk isolated and restored when appropriate.
Note For more information, see the "Scenario ③" section in O&M scenarios and system events for instances equipped with local disks.
Disk performance significantly affected Stalled Critical
  • Disk:Stalled:Executing
  • Disk:Stalled:Executed
This system event is triggered when the performance of a disk attached to an ECS instance is significantly affected. We recommend that you isolate reads and writes on the disk at the application layer or disassociate the ECS instance from the associated Server Load Balancer (SLB) instance.
Trusted Platform Module (TPM) security alert Security.TpmAlert Warning
  • Instance:Security.TpmAlert:Executing
  • Instance:Security.TpmAlert:Executed
This system event is triggered when an exception about the trusted system occurs on a security-enhanced instance. We recommend that you view event details in the ECS console to identify the exception cause and troubleshoot the exception. For more information, see Handle trusted exceptions.

Instance billing events

Event description ECS event type Event severity CloudMonitor event Time when a system event is triggered Handling suggestion for you
Subscription instance stop on expiration InstanceExpiration.Stop Critical
  • Instance:InstanceExpiration.Stop:Scheduled
  • Instance:InstanceExpiration.Stop:Executing
  • Instance:InstanceExpiration.Stop:Executed
  • Instance:InstanceExpiration.Stop:Avoided
This system event is triggered 3 days before a subscription instance expires and is stopped We recommend that you renew the instance at your earliest opportunity. For more information, see Renewal overview.
Subscription instance release after expiration InstanceExpiration.Delete Critical
  • Instance:InstanceExpiration.Delete:Scheduled
  • Instance:InstanceExpiration.Delete:Executing
  • Instance:InstanceExpiration.Delete:Executed
  • Instance:InstanceExpiration.Delete:Avoided
This system event is triggered 3 days before an expired subscription instance is automatically released We recommend that you renew the instance at your earliest opportunity. For more information, see Renewal overview.
Pay-as-you-go instance stop due to overdue payments AccountUnbalanced.Stop Critical
  • Instance:AccountUnbalanced.Stop:Scheduled
  • Instance:AccountUnbalanced.Stop:Executing
  • Instance:AccountUnbalanced.Stop:Executed
  • Instance:AccountUnbalanced.Stop:Avoided
This system event is triggered 1 hour before a pay-as-you-go instance is stopped due to an overdue payment We recommend that you maintain a sufficient balance within your payment account to prevent instances from being stopped.
Pay-as-you-go instance release due to overdue payments AccountUnbalanced.Delete Critical
  • Instance:AccountUnbalanced.Delete:Scheduled
  • Instance:AccountUnbalanced.Delete:Executing
  • Instance:AccountUnbalanced.Delete:Executed
  • Instance:AccountUnbalanced.Delete:Avoided
This system event is triggered 3 days before a pay-as-you-go instance is automatically released due to an overdue payment We recommend that you maintain a sufficient balance within your payment account to prevent instances from being released.
Disk release due to overdue payments Undefined Critical Disk:OverduePaymentRelease This system event is triggered when a pay-as-you-go disk is automatically released due to an overdue payment. We recommend that you maintain a sufficient balance within your payment account to prevent disks from being released.

State change events

Event description ECS event type Event severity CloudMonitor event Time when a system event is triggered Handling suggestion for you
Preemptible instance interruption Undefined Warning Instance:PreemptibleInstanceInterruption This system event is triggered 5 minutes before a preemptible instance is reclaimed. We recommend that you take one of the following actions:
  • Use preemptible instances for stateless applications, such as scalable web services and big data analytics applications.
  • Use Auto Provisioning to deliver instances and mitigate the impacts of reclaimed preemptible instances on your business. You can also implement automated O&M based on this event. For example, you can configure notifications about this event in the CloudMonitor console and have preemptible instances automatically purchased when a notification is sent.
Burstable instance performance limited to the baseline level due to insufficient CPU credits Undefined Warning Instance:BurstablePerformanceRestricted This system event is triggered when all accrued CPU credits of a burstable instance are consumed. We recommend that you take one of the following actions in response to the event:
  • If you want the burstable instance to run at a CPU utilization higher than the baseline for a short period of time, enable the unlimited mode for the instance for that period. For more information, see Switch the performance mode of a burstable instance.
  • If you want the burstable instance to run at a CPU utilization higher than the baseline for a long time, upgrade the instance to a higher-specification instance type or change the instance into a non-burstable instance. For more information, see Change instance types.

If you want to specify thresholds for triggering notifications about this event, for example, if you want an event notification to be sent when accrued CPU credits remain less than 10 for consecutive 10 minutes, you can configure event-triggered alert rules for the event in the CloudMonitor console. For more information, see Monitor burstable instances.

Performance mode change of burstable instances Undefined Warning Instance:PerformanceModeChange This system event is triggered when a burstable instance switches between the unlimited and standard modes. We recommend that you determine whether to follow the event. If you want to follow the event, you can configure notifications about the event in the CloudMonitor console. For more information, see Set event notifications.
Instance state change Undefined Notification Instance:StateChange This system event is triggered when the state of an instance changes, such as from Running to Stopping and from Stopping to Stopped. We recommend that you determine whether to follow the event. If you want to follow the event, you can configure notifications about the event in the CloudMonitor console. For more information, see Set event notifications.
Automatic instance reactivation Undefined Notification Instance:AutoReactivateCompleted This system event is triggered when an instance is automatically reactivated while overdue payments in your account are settled. We recommend that you determine whether to follow the event. If you want to follow the event, you can configure notifications about the event in the CloudMonitor console. For more information, see Set event notifications.
Hot migration of instances between dedicated hosts Undefined Notification Instance:LiveMigrationAcrossDDH This system event is triggered when an instance is hot migrated between dedicated hosts. We recommend that you determine whether to follow the event. If you want to follow the event, you can configure notifications about the event in the CloudMonitor console. For more information, see Set event notifications.
Disk operations completed Undefined Notification Disk:DiskOperationCompleted This system event is triggered when a pay-as-you-go disk is manually attached or detached. We recommend that you determine whether to follow the event. If you want to follow the event, you can configure notifications about the event in the CloudMonitor console. For more information, see Set event notifications.
Disk billing method change from subscription to pay-as-you-go Undefined Notification Disk:ConvertToPostpaidCompleted This system event is triggered when a subscription disk is changed to a pay-as-you-go disk. We recommend that you determine whether to follow the event. If you want to follow the event, you can configure notifications about the event in the CloudMonitor console. For more information, see Set event notifications.
Disk snapshot created Undefined Notification Snapshot:CreateSnapshotCompleted This system event is triggered when a snapshot is created for a disk. We recommend that you determine whether to follow the event. If you want to follow the event, you can configure notifications about the event in the CloudMonitor console. For more information, see Set event notifications.