Alibaba Cloud sends voice messages, emails, and internal messages to notify you of scheduled O&M events of ApsaraDB for HBase, for example, minor version upgrades. You are also notified in the ApsaraDB for HBase console. You can view the type, region, procedure, affected instances, considerations, and default switchover time of a scheduled event. You can also modify the scheduled switchover time.

Precautions

In most cases, Alibaba Cloud notifies you at least three days before system maintenance events such as minor version upgrades are executed. Notifications for high-risk vulnerability fixes are sent within three days before execution due to the urgency of these events.

Alibaba Cloud sends notifications by using voice messages, emails, internal messages, or messages in the ApsaraDB for HBase console. To ensure that you can receive notifications, log on to the Message Center, select ApsaraDB Fault or Maintenance Notifications, and then specify a contact. We recommend that you specify an O&M engineer as the contact. If you do not specify a contact, you cannot receive notifications.
Figure 1. Message Center settings
Settings

Procedure

  1. Log on to the ApsaraDB for HBase console.
  2. In the left-side navigation pane, choose Event Center > Scheduled Event.
  3. On the Scheduled Event page, view the details about the events.
    The event details include the instance ID, region, event type, cause, impact on business, scheduled switchover time, and status. For more information about the causes of events and the impacts of events on business, see Causes and impacts of events. View event details
  4. You can perform the following operations on an event.
    • Modify Scheduled Switching Time.
      You can use the default switchover time or modify the scheduled switchover time. The priority of the scheduled switchover time is higher than the priority of the default switchover time.
      1. On the Scheduled Event page, select one or more events.
      2. In the upper-right corner of the Scheduled Event page, click Add Scheduled Event.
      3. In the Add Scheduled Event panel, set the scheduled switchover time.

        If you want to immediately perform a switchover, select Earliest Execution Time. After you confirm the settings, the system immediately prepares for the switchover. If the preparation is already complete, the system immediately performs the switchover.

        Note The time that is specified by the Scheduled Switching Time parameter cannot be later than the time that is specified by the Latest Execution Time parameter.
      4. Check whether the events that you selected are the events for which you want to apply the scheduled switchover time.
        • If the events that you selected are the events for which you want to apply the scheduled switchover time, click OK.
        • Otherwise, select the events for which you want to apply the scheduled switchover time in the Scheduled Event list and reconfigure the scheduled switchover time.
    • Cancel the scheduled switchover for an event.

      You can cancel the scheduled switchover only for a minor version upgrade event. You can select a minor version upgrade event and click Cancel Scheduled Event in the upper-right corner.

Causes and impacts of events

Cause Impact Description
Minor version upgrades Transient connections At the scheduled switchover time, your instances may experience the following impacts. We recommend that you perform the switchover during off-peak hours and make sure that your applications are configured with a reconnection mechanism.
  • Single-zone instance: One switchover is performed. During the switchover, your instance or the data shards in your instance experience transient connections and stay in the read-only state for up to 30 seconds before all data synchronized.
  • Multi-zone instance: Two switchovers are performed. During the switchovers, your instance or the data shards in your instance experience transient connections and stay in the read-only state for up to 30 seconds before all data is synchronized. The second switchover switches the master node to the primary zone. This prevents an increase in access latency that may occur when the master node is in the secondary zone.
Differences between minor versions Different minor versions or kernel versions have different updates. For more information, see Release notes for minor versions.