Tair (Redis® OSS-Compatible):Use the scheduled auto scaling feature

Prerequisites

• The instance is a Redis Open-Source Edition instance or a Tair (Enterprise Edition) DRAM-based instance.

• The instance uses the standard architecture.

• The instance is deployed in cloud-native mode.

• The service-linked role for DAS is created. For more information, see AliyunServiceRoleForDAS role.

• The balance in your Alibaba Cloud account is sufficient for scale-ups.

Precautions

• To scale up a database instance on a regular basis, you must configure a scheduled auto scaling policy for the database instance.

• All time-related parameters are displayed in UTC+8. If this time zone is not supported in your region, you must convert the time before you configure the parameters.

• You can apply only one auto scaling policy of each mode to a database instance.

• Retry intervals are not supported for scheduled auto scaling policies. If a scheduled auto scaling policy fails to be executed, the system does not retry to execute the policy.

• If the Duration or Scale-back Time parameter is modified after an instance is scaled up, the instance is scaled back to the previous specifications based on the new time specified by either of the two parameters.

• In the following scenarios, the database instance may not be scaled back to its previous specifications even if the Duration or Scale-back Time parameter is specified:

  • The specifications of the database instance are manually or automatically changed again after the scheduled auto scaling policy is executed. If the instance specifications are different from those specified in the policy, the database instance is not scaled back.

  • One or more metrics of the database instance do not meet specific standards. For example, the memory of an instance is scaled up from 1 GB to 4 GB based on a scheduled auto scaling policy. If 1 GB of memory has been used before the instance is scaled back, the scale-back operation is not performed because the memory usage increases to 100% during the operation. This ensures the stability and security of your business.

  • The instance is in a state in which specification changes are not allowed, such as the Changing Specifications or Migrating state.

Examples

DAS performs scaling operations on your instances once or on a regular basis. DAS may scale your instances every day, week, or month. For example, if the peak hours of your business start at 2:00 on the first day of every month and end at 2:00 on the third day of every month, you can use the scheduled auto scaling feature to scale up your instances during peak hours and scale the instances back during off-peak hours.

Billing

When you change the specifications of a database instance by using the scheduled auto scaling feature, you are charged for the specification change. For more information, see Configuration changes.

Create a scheduled auto scaling policy

1. Log on to the console and go to the Instances page. In the top navigation bar, select the region in which the instance that you want to manage resides. Then, find the instance and click the instance ID.

2. In the left-side navigation pane, choose CloudDBA > Performance Trends.

3. On the Performance Trends page, click Autonomy Service Settings.

4. On the Autonomous Function Settings tab of the Autonomous Function Management panel, click the Auto Scaling tab. On the Auto Scaling tab, click Add Policy. In the Add Policy panel, configure the parameters described in the following table.

   Parameter	Description
   Policy Name	The name of the policy.
   Mode	The mode of the policy. Select Scheduled Auto Scaling from the Mode drop-down list.
   Engine Type	The type of the database engine.
   Specifications	The specifications of the instance that runs the selected database engine.
   Operation	The scaling operation that you can perform. Only Adjust Instance Specifications is supported.
   Valid From	The time range during which the policy is effective. The start time must be specified and must be later than the current date. The end time can be specified or left empty. If you set Recurrence to N/A(Execute Only Once), the scheduled auto scaling policy is executed only once and is not subject to the end time. If you set Recurrence to Daily, Weekly, or Monthly and leave the end time empty, the auto scaling policy is repeatedly executed based on the specified cycle. If you specify the end time, the validity of the policy is subject to the end time.
   Recurrence	The interval at which the scaling operation is performed. Valid values: N/A(Execute Only Once) Scaling Start Time: You must specify this parameter. Duration: You can set this parameter to a positive integer or leave this parameter empty. Unit: hours. This parameter is optional. If you leave the Duration parameter empty, the instance cannot be scaled back. If you specify the Duration parameter, the instance can be scaled back to its previous specifications after the specified duration. Daily: Scaling Start Time: You must specify this parameter. Scale-back Time: You must specify this parameter. If the scaling start time is earlier than the scale-back time, the specified scaling operation starts and ends on the same day. If the scaling start time is later than the scale-back time, the specified scaling operation starts at the scaling start time on the specified day and ends at the scale-back time of the following day. Note The scale-back time must be at least 1 hour later than the scaling start time. The scaling start time must be at least 1 hour later than the scale-back time of the previous scaling operation. If the end time of the policy validity period is specified and the scaling start time is later than the scale-back time, the specified scaling operation that is scheduled the day before the specified end time is no longer performed. Weekly: Scaling Start Time: You must specify this parameter. Scale-back Time: You must specify this parameter. If the scaling start time is earlier than the scale-back time, the specified scaling operation starts and ends on the same week. If the scaling start time is later than the scale-back time, the specified scaling operation starts at the scaling start time in the specified week and ends at the scale-back time of the following week. Note The scale-back time must be at least 1 hour later than the scaling start time. The scaling start time must be at least 1 hour later than the scale-back time of the previous scaling operation. If the end time of the policy validity period is specified and the scaling start time is later than the scale-back time, the specified scaling operation that is scheduled the day before the specified end time is no longer performed. Monthly: Scaling Start Time: You must specify this parameter. Scale-back Time: You must specify this parameter. If the scaling start time is earlier than the scale-back time, the specified scaling operation starts and ends on the same month. If the scaling start time is later than the scale-back time, the specified scaling operation starts at the scaling start time in the specified month and ends at the scale-back time of the following month. Note The scale-back time must be at least 1 hour later than the scaling start time. The scaling start time must be at least 1 hour later than the scale-back time of the previous scaling operation. If the end time of the policy validity period is specified and the scaling start time is later than the scale-back time, the specified scaling operation that is scheduled the day before the specified end time is no longer performed.

5. In the Recommended Policies section, click Apply in the Actions column corresponding to the policy that you want to apply.

   Note

   • To modify a policy, click Modify in the Actions column corresponding to the policy. In the Update Policy panel, modify the policy settings.

   • If you no longer want to apply a policy to your instance, click Cancel in the Actions column corresponding to the policy in the Applied Policy section.

6. Click OK.

View the results of scheduled auto scaling

1. Log on to the DAS console.

2. In the left-side navigation pane, click Instance Monitoring.

3. On the page that appears, find the instance that you want to manage and click the instance ID. The instance details page appears.

4. In the left-side navigation pane, click Autonomy Center.

5. On the Autonomy Center page, select a time range and filter the auto scaling events that occurred during the selected time range.

6. Click Details in the Auto-Scaling Events section to view the details of auto scaling events.

   

FAQ

I want to scale up my instance, but the specifications of the instance have reached the upper limit. What do I do?

We recommend that you purchase an instance that runs a higher edition, and then migrate data from your instance to the new instance. For more information about the instance specifications and migration solutions, see Instance specifications and Migrate data between Tair instances.