This topic describes how to create an event notification in a scaling group. After an event of the specified type occurs, Auto Scaling automatically sends a notification to the specified Message Service (MNS) topic, MNS queue, or CloudMonitor.

Prerequisites

If you want Auto Scaling to automatically send messages to an MNS topic or queue, Create a topic or Create a queue in advance. Ensure that the MNS topic or queue belongs to the same region where the scaling group resides.

Background information

  • Only a limited number of event notifications can be created in a scaling group. For more information, see Limits.
  • Receivers in a scaling group must be unique. For example, CloudMonitor, the same MNS topic, or the same MNS queue cannot be used for different event notifications in a scaling group.

Procedure

  1. Log on to the Auto Scaling console.
  2. In the left-side navigation pane, click Scaling Groups.
  3. In the top navigation bar, select a region.
  4. You can use either of the following methods to open the details page of a scaling group.
    • In the Scaling Group Name/ID column, click a scaling group name.
    • Click Manage in the Actions column corresponding to a scaling group.
  5. In the left-side navigation pane, click Event Notifications.
  6. Click Create Event Notification.
  7. Configure parameters to create an event notification.
    1. Configure the notification method.
      Notification method Description
      CloudMonitor If a specific event occurs, a notification is sent to CloudMonitor. For more information, see View cloud service events.
      MNS Topic If a specific event occurs, a notification is sent to an MNS topic.
      MNS Queue If a specific event occurs, a notification is sent to an MNS queue.
    2. Configure the event types.
      You can select multiple event types.
      Event type Description
      Successful Scale-out Event ECS instances are added to the scaling group.
      Successful Scale-in Event ECS instances are removed from the scaling group.
      Failed Scale-out Event Scale-out events were triggered but ECS instances failed to be added to the scaling group.
      Failed Scale-in Event Scale-in events were triggered but ECS instances failed to be removed from the scaling group.
      Rejected Scaling Activity The scaling group received the scaling request but rejected the request because the triggering conditions are not met.
      Start of Scale-out Event Scale-out events were triggered and ECS instances are being added to the scaling group.
      Start of Scale-in Event Scale-in events were triggered and ECS instances are being removed from the scaling group.
      Expiration of Scheduled Task If you select this type, notifications will be sent on a daily basis for seven days before the scheduled task expires.

      If you specify the frequency for the scheduled task, the task expiration time is the last time when the task will be executed.

      Note Scaling activities can be successful or partly successful activities. You can view the details of a scaling activity to check the execution result.
  8. Click Create Event Notification.