Summary - Elastic Compute Service - Alibaba Cloud Documentation Center

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 code 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 code	Event name	Event severity	CloudMonitor event	Event description and impact	Handling suggestion
SystemMaintenance.Reboot	Instance Restart Due to System Maintenance	Critical	Instance:SystemMaintenance.Reboot:Inquiring: Querying Instance Restart Due to System Maintenance Instance:SystemMaintenance.Reboot:Scheduled: Instance Restart Scheduled Due to System Maintenance Instance:SystemMaintenance.Reboot:Executing: Restarting Instance Due to System Maintenance Instance:SystemMaintenance.Reboot:Executed: Instance Restarted Due to System Maintenance Instance:SystemMaintenance.Reboot:Avoided: Instance Restart Avoided Due to System Maintenance Instance:SystemMaintenance.Reboot:Failed: Instance Restart Failed Due to System Maintenance Instance:SystemMaintenance.Reboot:Canceled: Instance Restart Canceled Due to System Maintenance	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 and the risk causes instance restarts.	We recommend that you take one of the following actions in response to the event: Modify the scheduled restart time of the instance. For more information, see Modify the scheduled restart time. Restart the instance. For more information, see Restart an instance. Wait for the instance to be automatically restarted. Note We recommend that you pay attention to the status of the event. If the event status remains unchanged after the instance is restarted, the event handling fails and the risk is not mitigated. To mitigate the risk, we recommend that you select a point in time that is at least 12 hours apart from the time of the current operation to restart the instance. 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.
SystemMaintenance.Stop	Instance Stopped Due to System Maintenance	Critical	Instance:SystemMaintenance.Stop:Scheduled: Instance Stop Scheduled Due to System Maintenance Instance:SystemMaintenance.Stop:Executing: Stopping Instance Due to System Maintenance Instance:SystemMaintenance.Stop:Executed: Instance Stopped Due to System Maintenance Instance:SystemMaintenance.Stop:Avoided: Instance Stop Avoided Due to System Maintenance Instance:SystemMaintenance.Stop:Failed: Instance Stop Failed Due to System Maintenance Instance:SystemMaintenance.Stop:Canceled: Instance Stop Canceled Due to System Maintenance	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 and the risk causes the instance to stop.	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.
SystemMaintenance.Redeploy	Instance Redeployment Due to System Maintenance	Critical	Instance:SystemMaintenance.Redeploy:Inquiring: Querying Instance Redeployment Due to System Maintenance Instance:SystemMaintenance.Redeploy:Scheduled: Instance Redeployment Scheduled Due to System Maintenance Instance:SystemMaintenance.Redeploy:Executing: Redeploying Instance Due to System Maintenance Instance:SystemMaintenance.Redeploy:Executed: Instance Redeployed Due to System Maintenance Instance:SystemMaintenance.Redeploy:Avoided: Instance Redeployment Avoided Due to System Maintenance Instance:SystemMaintenance.Redeploy:Canceled: Instance Redeployment Canceled Due to System Maintenance	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 and the risk causes instance redeployment. Important If the instance is equipped with local SSDs or HDDs, the data disks are re-initialized and local disk data is cleared.	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: Redeploy the instance. For more information, see Redeploy an instance equipped with local disks. Wait for the instance to be automatically redeployed. Note We recommend that you pay attention to the status of the event. If the event status remains unchanged after the instance is redeployed, the event handling fails and the risk is not mitigated. To mitigate the risk, we recommend that you select a point in time that is at least 12 hours apart from the time of the current operation to redeploy the instance. 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.
SystemMaintenance.IsolateErrorDisk	Isolation of Damaged Local Disks Due to System Maintenance	Critical	Instance:SystemMaintenance.IsolateErrorDisk:Inquiring: Querying Damaged Disk Isolation Due to System Maintenance Instance:SystemMaintenance.IsolateErrorDisk:Executing: Isolating Damaged Disk Due to System Maintenance Instance:SystemMaintenance.IsolateErrorDisk:Executed: Damaged Disk Isolated Due to System Maintenance Instance:SystemMaintenance.IsolateErrorDisk:Avoided: Damaged Disk Isolation Avoided Due to System Maintenance Instance:SystemMaintenance.IsolateErrorDisk:Failed: Damaged Disk Isolation Failed Due to System Maintenance Instance:SystemMaintenance.IsolateErrorDisk:Canceled: Damaged Disk Isolation Canceled Due to System Maintenance	This system event is immediately triggered when Alibaba Cloud detects hardware damage or software damage in a local disk of an instance. Important The procedure for handling 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 then 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.
SystemMaintenance.ReInitErrorDisk	Re-initialization of Damaged Local Disks Due to System Maintenance	Critical	Instance:SystemMaintenance.ReInitErrorDisk:Inquiring: Querying Damaged Disk Re-initialization Due to System Maintenance Instance:SystemMaintenance.ReInitErrorDisk:Executing: Re-initializing Damaged Disk Due to System Maintenance Instance:SystemMaintenance.ReInitErrorDisk:Executed: Damaged Disk Re-initialized Due to System Maintenance Instance:SystemMaintenance.ReInitErrorDisk:Avoided: Damaged Disk Re-initialization Avoided Due to System Maintenance Instance:SystemMaintenance.ReInitErrorDisk:Failed: Damaged Disk Re-initialization Failed Due to System Maintenance Instance:SystemMaintenance.ReInitErrorDisk:Cancele: Damaged Disk Re-initialization Canceled Due to System Maintenance	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 hardware damage 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 for handling 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 then 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.
SystemMaintenance.RebootAndIsolateErrorDisk	Isolation of Damaged Local Disks and Instance Restart Due to System Maintenance	Critical	Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Inquiring: Querying Instance Restart and Damaged Disk Isolation Due to System Maintenance Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Executing: Restarting Instance and Isolating Damaged Disk Due to System Maintenance Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Executed: Instance Restarted and Damaged Disk Isolated Due to System Maintenance Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Avoided: Instance Restart and Damaged Disk Isolation Avoided Due to System Maintenance Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Canceled: Instance Restart and Damaged Disk Isolation Canceled Due to System Maintenance	This system event is immediately triggered when Alibaba Cloud detects hardware damage or software damage in a local disk of an instance and fails to isolate the local disk online. Important The procedure for handling 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 then 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.
SystemMaintenance.RebootAndReInitErrorDisk	Re-initialization of Damaged Local Disks and Instance Restart Due to System Maintenance	Critical	Instance:SystemMaintenance.RebootAndReInitErrorDisk:Inquiring: Querying Instance Restart and Damaged Disk Re-initialization Due to System Maintenance Instance:SystemMaintenance.RebootAndReInitErrorDisk:Executing: Restarting Instance and Re-initializing Damaged Disk Due to System Maintenance Instance:SystemMaintenance.RebootAndReInitErrorDisk:Executed: Instance Restarted and Damaged Disk Re-initialized Due to System Maintenance Instance:SystemMaintenance.RebootAndReInitErrorDisk:Avoided: Instance Restart and Damaged Disk Re-initialization Avoided Due to System Maintenance Instance:SystemMaintenance.RebootAndReInitErrorDisk:Canceled: Instance Restart and Damaged Disk Re-initialization Canceled Due to System Maintenance	This system event is immediately triggered when Alibaba Cloud detects hardware damage or software damage in a local disk of an instance and fails to restore the local disk online. Important The procedure for handling 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 then 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.
SystemMaintenance.StopAndRepair	In-place Repair of Instance Equipped With Local Disks	Critical	Instance:SystemMaintenance.StopAndRepair:Inquiring: Querying Instance Stop and Repair Instance:SystemMaintenance.StopAndRepair:Scheduled: Instance Stop and Repair Scheduled Instance:SystemMaintenance.StopAndRepair:Executing: Stopping and Repairing Instance Instance:SystemMaintenance.StopAndRepair:Executed: Instance Stopped and Repaired Instance:SystemMaintenance.StopAndRepair:Avoided: Instance Stop and Repair 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. Note For more information, see O&M scenarios and system events for instances equipped with local disks.

Unexpected O&M events


Event code	Event name	Event severity	CloudMonitor event	Event description and impact	Handling suggestion
SystemFailure.Reboot	Instance Restart Due to System Error	Critical	Instance:SystemFailure.Reboot:Executing: Restarting Instance Due to System Error Instance:SystemFailure.Reboot:Executed: Instance Restarted Due to System Error Instance:SystemFailure.Reboot:Failed: Instance Restart Failed Due to System Error	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, such as CPU or memory hardware damage.	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. When the instance is being restarted, Alibaba Cloud migrates the instance to a healthy host. 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.
InstanceFailure.Reboot	Instance Restart Due to Instance Error	Critical	Instance:InstanceFailure.Reboot:Executing: Restarting Instance Due to Instance Error Instance:InstanceFailure.Reboot:Executed: Instance Restarted Due to Instance Error	This system event is immediately triggered when Alibaba Cloud detects that an instance is restarted due to an out-of-memory (OOM) exception or a kernel panic in the operating system of the instance.	We recommend that you wait until the instance is automatically restarted and then check whether the instance and applications work as expected. You can enable the kdump service of the operating system to troubleshoot the issue and prevent the issue from recurring. For more information, see Enable the Kernel Memory Dump feature for a Linux instance and Enable the Kernel Memory Dump feature for a Windows instance.
SystemFailure.Stop	Instance Stop Due to System Error	Critical	Instance:SystemFailure.Stop:Executing: Stopping Instance Due to System Error Instance:SystemFailure.Stop:Executed: Instance Stopped Due to System Error	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, such as CPU or memory hardware damage.	We recommend that you wait until the instance is automatically restarted and then start the instance. When the instance is being started, Alibaba Cloud migrates the instance to a healthy host. 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.
SystemFailure.Redeploy	Instance Redeployment Due to System Error	Critical	Instance:SystemFailure.Redeploy:Inquiring: Querying Instance Redeployment Due to System Error Instance:SystemFailure.Redeploy:Scheduled: Instance Redeployment Scheduled Due to System Error Instance:SystemFailure.Redeploy:Executing: Redeploying Instance Due to System Error Instance:SystemFailure.Redeploy:Executed: Instance Redeployed Due to System Error Instance:SystemFailure.Redeploy:Avoided: Instance Redeployment Avoided Due to System Error Instance:SystemFailure.Redeploy:Canceled: Instance Redeployment Canceled Due to System Error	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: Redeploy the instance. For more information, see Redeploy an instance equipped with local disks. Wait for the instance to be automatically redeployed. 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.
SystemFailure.Delete	Automatic Cancellation of Bills Due to Instance Creation Failures	Critical	Instance:SystemFailure.Delete:Executing: Canceling Order Due to Instance Creation Failure Instance:SystemFailure.Delete:Executed: Order Canceled Due to Instance Creation Failure Instance:SystemFailure.Delete:Avoided: Order Cancellation Avoided Due to Instance Creation Failure	This system event is immediately triggered when Alibaba Cloud detects that an order is placed but the instance fails to 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.
ErrorDetected	Local Disk Fault Alarm	Critical	Disk:ErrorDetected:Executing: Local Disk Fault Alarm Started Disk:ErrorDetected:Executed: Local Disk Fault Alarm Ended	This system event is immediately triggered when Alibaba Cloud detects hardware or software failure in the local disk of an instance and data cannot be read from the disk or written to the disk.	We recommend that you complete the required preparations such as modifying the /etc/fstab configuration file and backing up data. Then, make sure that the damaged local disk is isolated and restored based on your needs. Supported operations vary based on instance types: d1, d1ne, d2s, and d2c: supports online isolation, offline isolation, online repair, and redeployment. d3c, d2c, i2, i2g, i2ne, i2gne, i3, and i3g: supports online isolation, offline isolation, and redeployment. i1: supports redeployment. ebmi2g: supports authorized repair and redeployment. Note For more information, see the "Scenario ③" section in O&M scenarios and system events for instances equipped with local disks.
Stalled	Severe Impacts on Disk Performance	Critical	Disk:Stalled:Executing: Severe Impacts on Disk Performance Started Disk:Stalled:Executed: Severe Impacts on Disk Performance Ended	This system event is immediately triggered when Alibaba Cloud detects that an I/O hang occurs on a disk of the instance, which significantly affects the disk performance and prevents the disk from handling read and write requests.	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.

Instance migration events due to upgrades at the underlying layer


Event code	Event name	Event severity	CloudMonitor event	Event description and impact	Handling suggestion
SystemUpgrade.Migrate	Instance Migration Events Due to Upgrades at Underlying Layer	Critical	Undefined	This 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 code	Event name	Event severity	CloudMonitor event	Event description and impact	Handling suggestion
Instance:BurstablePerformanceRestricted	Limited Performance of Burstable Instance	Warning	Instance:BurstablePerformanceRestricted: Burstable Instance Performance Limited	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.

State change events


Event code	Event name	Event severity	CloudMonitor event	Event description and impact	Handling suggestion
Instance:PreemptibleInstanceInterruption	Preemptible Instance Interruption	Warning	Instance:PreemptibleInstanceInterruption: Notification on Preemptible Instance Interruption	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.
Instance:PerformanceModeChange	Performance Mode Switchover of Burstable Instance	Warning	Instance:PerformanceModeChange: Performance Mode Switchover of Burstable Instance	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 Configure event notifications.
Instance:StateChange	Instance Status Change	Notification	Instance:StateChange: Notification on Instance Status Change	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 Configure event notifications.
Instance:AutoReactivateCompleted	Automatic Restart Completed	Notification	Instance:AutoReactivateCompleted: Automatic Restart Completed	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 Configure event notifications.
Instance:LiveMigrationAcrossDDH	Instance Hot Migration Between Dedicated Hosts	Notification	Instance:LiveMigrationAcrossDDH: Instance Hot Migration Between Dedicated Hosts	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 Configure event notifications.
Disk:DiskOperationCompleted	Disk Operations Completed	Notification	Disk:DiskOperationCompleted: Disk Operations Completed	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 Configure event notifications.
Disk:ConvertToPostpaidCompleted	Billing Method of Disks Switched to Pay-as-you-go	Notification	Disk:ConvertToPostpaidCompleted: Billing Method of Disks Switched to Pay-as-you-go	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 Configure event notifications.
Snapshot:CreateSnapshotCompleted	Disk Snapshot Created	Notification	Snapshot:CreateSnapshotCompleted: Disk Snapshot Created	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 Configure event notifications.