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Cloud Monitor:System events automatically monitored by Cloud Monitor

Last Updated:Nov 07, 2025

If a specified system event occurs in Elastic Compute Service (ECS), Cloud Monitor, ApsaraDB for OceanBase, and Web Application Firewall (WAF), Cloud Monitor automatically sends alert notifications to the message recipients through Message Center.

The following table describes the system events for which Cloud Monitor automatically sends alert notifications.

Alibaba Cloud service

Event type

Event name

Event description

Event status

Event severity

ECS

Exception

Instance:SystemFailure.Reboot:Executed

The instance reboot that is caused by a system error is completed.

Executed

Critical

StatusNotification

Instance:AutoReactivateCompleted

An ECS instance is automatically restarted.

Normal

Info

Notification

Instance:TempBandwidthDowngrade

The temporary bandwidth of an ECS instance expires.

Normal

Info

Exception

Disk:Stalled:Executed

The impact on the disk performance ends.

Executed

Critical

Exception

Disk:Stalled:Executing

The impact on the disk performance starts.

Executing

Critical

Exception

Instance:InstanceFailure.Reboot:Executed

The instance reboot that is caused by an instance error is completed.

Executed

Critical

Exception

Instance:SystemFailure.Reboot:Executing

The instance reboot that is caused by a system error starts.

Executing

Critical

Maintenance

Instance:SystemMaintenance.IsolateErrorDisk:Inquiring

The damaged-disk isolation that is caused by system maintenance is waiting for your confirmation.

Inquiring

Critical

Maintenance

Instance:SystemMaintenance.ReInitErrorDisk:Inquiring

The damaged-disk reinitialization that is caused by system maintenance is waiting for your confirmation.

Inquiring

Critical

Maintenance

Instance:SystemMaintenance.Reboot:Scheduled

The instance reboot that is caused by system maintenance is scheduled.

Scheduled

Critical

Maintenance

Instance:SystemMaintenance.RebootAndIsolateErrorDisk:Inquiring

The instance reboot and damaged-disk isolation that are caused by system maintenance are waiting for your confirmation.

Inquiring

Critical

Maintenance

Instance:SystemMaintenance.RebootAndReInitErrorDisk:Inquiring

The instance reboot and damaged-disk reinitialization that are caused by system maintenance are waiting for your confirmation.

Inquiring

Critical

Maintenance

Instance:SystemMaintenance.Redeploy:Inquiring

The scheduled instance redeployment that is caused by system maintenance is waiting for your confirmation.

Inquiring

Critical

Maintenance

Instance:SystemMaintenance.Redeploy:Scheduled

The instance redeployment that is caused by system maintenance is scheduled.

Scheduled

Critical

Exception

Instance:SystemFailure.Stop:Executing

The instance stop that is caused by a system error starts.

Executing

Critical

Cloud Monitor

Alert

AlertWebHook

A callback event occurs.

Alarm

Info

ApsaraDB for OceanBase

StatusNotification

Instance:DataDisk:Full

The disk space of an ApsaraDB for OceanBase instance is insufficient.

Normal

Critical

WAF

Exceed

waf_event_qps_exceed

The queries per second (QPS) exceeds the threshold.

Overrun

Critical

Exceed

waf_event_bandwidth_exceed

The bandwidth exceeds the threshold.

Overrun

Critical