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

Note If Undefined is displayed in the Event name column of a system event, the system event is not displayed in the ECS console and cannot be queried by calling API operations. Example: the Instance:StateChange event.

Scheduled O&M events

Event descriptionEvent nameEvent severityCloudMonitor eventReason why and time when a system event is triggeredHandling suggestion
Scheduled instance restart due to system maintenanceSystemMaintenance.RebootCritical
  • 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 to 48 hours before the scheduled time of system maintenance when Alibaba Cloud detects a potential risk of hardware or software failure in the underlying host of an instance. 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 Modify instance maintenance attributes.
Scheduled instance stop due to system maintenanceSystemMaintenance.StopCritical
  • 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 to 48 hours before the scheduled time of system maintenance when Alibaba Cloud detects a potential risk of hardware or software failure in the underlying host of an instance. 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 Modify instance maintenance attributes.
Scheduled instance redeployment due to system maintenanceSystemMaintenance.RedeployCritical
  • 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 to 48 hours before the scheduled time of system maintenance when Alibaba Cloud detects a potential risk of hardware or software failure in the underlying host of an instance.
Note Only instances that depend on host hardware support this system 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 Modify instance maintenance attributes.
Isolation of damaged local disks due to system maintenanceSystemMaintenance.IsolateErrorDiskCritical
  • 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 immediately triggered when Alibaba Cloud detects a hardware or software damage in a local disk of an instance.
Important The procedure to handle a damaged local disk of an instance varies based on the instance type. For specific instance types, the instance must be restarted and the damaged local disk must be isolated. For other instance types, the damaged local disk can be isolated online and repaired.
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 maintenanceSystemMaintenance.ReInitErrorDiskCritical
  • 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 immediately triggered when Alibaba Cloud isolates and replaces a local disk on the host of an instance after Alibaba Cloud detects a hardware or software damage in the local disk. In most cases, Alibaba Cloud isolates and replaces a damaged local disk within five business days after you authorize Alibaba Cloud to isolate the local disk.
Important The procedure to handle a damaged local disk of an instance varies based on the instance type. For specific instance types, the instance must be restarted and the damaged local disk must be isolated. For other instance types, the damaged local disk can be isolated online and repaired.
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 maintenanceSystemMaintenance.RebootAndIsolateErrorDiskCritical
  • Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Inquiring
  • Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Executing
  • Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Executed
  • Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Avoided
  • Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Canceled
This system event is immediately triggered when Alibaba Cloud detects a hardware or software damage in a local disk of an instance and fails to isolate the local disk online.
Important The procedure to handle a damaged local disk of an instance varies based on the instance type. For specific instance types, the instance must be restarted and the damaged local disk must be isolated. For other instance types, the damaged local disk can be isolated online and repaired.
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 maintenanceSystemMaintenance.RebootAndReInitErrorDiskCritical
  • Instance:SystemMaintenance.RebootAndReInitErrorDisk:Inquiring
  • Instance:SystemMaintenance.RebootAndReInitErrorDisk:Executing
  • Instance:SystemMaintenance.RebootAndReInitErrorDisk:Executed
  • Instance:SystemMaintenance.RebootAndReInitErrorDisk:Avoided
  • Instance:SystemMaintenance.RebootAndReInitErrorDisk:Canceled
This system event is immediately triggered when Alibaba Cloud detects a hardware or software damage in a local disk of an instance and fails to restore the local disk online.
Important The procedure to handle a damaged local disk of an instance varies based on the instance type. For specific instance types, the instance must be restarted and the damaged local disk must be isolated. For other instance types, the damaged local disk can be isolated online and repaired.
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.
In-place repair of instance equipped with local disksSystemMaintenance.StopAndRepairCritical
  • Instance:SystemMaintenance.StopAndRepair:Inquiring
  • Instance:SystemMaintenance.StopAndRepair:Scheduled
  • Instance:SystemMaintenance.StopAndRepair:Executing
  • Instance:SystemMaintenance.StopAndRepair:Executed
  • Instance:SystemMaintenance.StopAndRepair:Avoided
This system event is triggered 48 to 168 hours before the scheduled time of system maintenance when Alibaba Cloud detects a risk of hardware failure in the underlying host of an instance. We recommend that you select an appropriate period of time to authorize Alibaba Cloud to repair or redeploy the instance that is equipped with local disks.

Unexpected O&M events

Event descriptionEvent nameEvent severityCloudMonitor eventTime when a system event is triggeredHandling suggestion
Instance restart due to a system errorSystemFailure.RebootCritical
  • Instance:SystemFailure.Reboot:Executing
  • Instance:SystemFailure.Reboot:Executed
  • Instance:SystemFailure.Reboot:Failed
This system event is immediately triggered when Alibaba Cloud detects that an instance is restarted due to hardware or software failure in the underlying host. 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 Modify instance maintenance attributes.
Instance restart due to an instance errorInstanceFailure.RebootCritical
  • Instance:InstanceFailure.Reboot:Executing
  • Instance:InstanceFailure.Reboot:Executed
This system event is immediately triggered when Alibaba Cloud detects that an instance is restarted due to a kernel panic in the operating system of the instance. 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 View system logs and screenshots.
Instance stop due to a system errorSystemFailure.StopCritical
  • Instance:SystemFailure.Stop:Executing
  • Instance:SystemFailure.Stop:Executed
This system event is immediately triggered when Alibaba Cloud detects that an instance is stopped due to hardware or software failure in the underlying host. 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 Modify instance maintenance attributes.
Instance redeployment due to a system errorSystemFailure.RedeployCritical
  • 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 immediately triggered when Alibaba Cloud detects hardware or software failure in the underlying host of an instance equipped with local disks and the instance must be redeployed.
Note Only instances that depend on host hardware support this system 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 Modify instance maintenance attributes.
Instance release due to a creation failureSystemFailure.DeleteCritical
  • Instance:SystemFailure.Delete:Executing
  • Instance:SystemFailure.Delete:Executed
This system event is immediately triggered when Alibaba Cloud detects that an instance you order cannot be created. 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 disksErrorDetectedCritical
  • Disk:ErrorDetected:Executing
  • Disk:ErrorDetected:Executed
This system event is immediately triggered when Alibaba Cloud detects a hardware or software damage in a local disk of an instance. 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 affectedStalledCritical
  • Disk:Stalled:Executing
  • Disk:Stalled:Executed
This system event is immediately triggered when Alibaba Cloud detects that the performance of cloud disks on an 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 alertSecurity.TpmAlertWarning
  • Instance:Security.TpmAlert:Executing
  • Instance:Security.TpmAlert:Executed
This system event is immediately triggered when Alibaba Cloud detects an exception about the trusted system 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 migration events due to upgrades at the underlying layer

Event descriptionEvent nameEvent severityCloudMonitor eventTime when a system event is triggeredHandling suggestion
Instance migration due to upgrades at the underlying layerSystemUpgrade.MigrateCriticalUndefinedThis system event is triggered when instances are affected by the upgrades and improvements of physical infrastructure in regions and zones where these instances resides. We recommend that you view event details in the ECS console and migrate affected instances as instructed. For more information, see Instance migration due to upgrades at the underlying layer.

Performance limited events of burstable instances

Event descriptionEvent nameEvent severityCloudMonitor eventTime when a system event is triggeredHandling suggestion
Burstable instance performance limited to the baseline level due to insufficient CPU creditsUndefinedWarningInstance:BurstablePerformanceRestrictedThis 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.

State change events

Event descriptionEvent nameEvent severityCloudMonitor eventTime when a system event is triggeredHandling suggestion
Preemptible instance interruptionUndefinedWarningInstance:PreemptibleInstanceInterruptionThis 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.
Performance mode change of burstable instancesUndefinedWarningInstance:PerformanceModeChangeThis 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 Configure event notifications.
Instance state changeUndefinedNotificationInstance:StateChangeThis 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 Configure event notifications.
Automatic instance reactivationUndefinedNotificationInstance:AutoReactivateCompletedThis 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 Configure event notifications.
Hot migration of instances between dedicated hostsUndefinedNotificationInstance:LiveMigrationAcrossDDHThis 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 Configure event notifications.
Disk operations completedUndefinedNotificationDisk:DiskOperationCompletedThis 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 Configure event notifications.
Disk billing method change from subscription to pay-as-you-goUndefinedNotificationDisk:ConvertToPostpaidCompletedThis 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 Configure event notifications.
Disk snapshot createdUndefinedNotificationSnapshot:CreateSnapshotCompletedThis 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 Configure event notifications.