Tair (Redis® OSS-Compatible):Enable bandwidth auto scaling

Prerequisites

The instance is a Redis Open-Source Edition instance or a Tair (Enterprise Edition) memory-optimized or persistent memory-optimized instance.

Function overview

Because different instance types have different bandwidth allocations, if traffic exceeds the bandwidth limit, network congestion may occur and instance performance may deteriorate. You can enable the bandwidth auto scaling feature to prevent these situations. Compared to changing instance specifications, adjusting bandwidth helps you quickly increase bandwidth, reduce overall costs, and avoid connection interruptions, allowing for immediate use.

Limits

• After the bandwidth of an instance is automatically upgraded, a cooldown period of at least 1 hour is required before automatic bandwidth scale-back can be triggered. Additionally, a cooldown time of 1 minute is required between two automatic bandwidth expansion operations.

• The bandwidth of an instance can be increased by up to six times the default bandwidth of the instance type, with a cap at 192 MB/s.

  Note

  Examples:

  • If the default bandwidth of a 2 GB standard Tair memory-optimized instance is 96 MB/s, the maximum bandwidth of the instance can be 96 MB/s + 192 MB/s = 288 MB/s.

  • If the default bandwidth of a 256 MB standard Redis Open-Source Edition instance is 10 MB/s, the bandwidth of the instance can be increased by up to 60 MB/s. As a result, the maximum bandwidth of the instance can be 10 MB/s + 60 MB/s = 70 MB/s.

  To further increase the bandwidth of the instance, you can upgrade the instance specifications or instance architecture. For example, you can change the standard architecture to the cluster architecture. For more information, see Instance specifications.

• We recommend that you do not manually adjust the instance bandwidth and enable bandwidth auto scaling for the instance at the same time.

  If you use both methods: If the manually set bandwidth reaches the upper limit, automatic bandwidth expansion is not triggered. As the traffic decreases, automatic bandwidth scale-back reduces the manually set bandwidth to the default bandwidth of the instance type.

  Note

  Examples:

  • The default bandwidth of an instance is 10 MB/s. After you manually set the bandwidth to 70 MB/s, automatic bandwidth expansion is not triggered when the threshold is reached because the bandwidth exceeds the upper limit of six times the default bandwidth.

  • If you manually set the bandwidth of an instance of the same type to 40 MB/s, automatic bandwidth expansion increases the bandwidth to a maximum of 70 MB/s when the threshold is reached. When the scale-down threshold is reached, the bandwidth is decreased until it reaches the default bandwidth of 10 MB/s.

• If an instance has unexpired bandwidth plans, you cannot enable bandwidth auto scaling for the instance. In this case, you must unsubscribe from the bandwidth plans. For more information, see Refund management.

• If you perform one of the following operations, bandwidth auto scaling is disabled for your instance. You must re-enable this feature for the instance based on your needs:

  Operation	Exception
  Upgrade the major version	N/A
  Change the configurations of an instance	If the instance uses the standard architecture, the bandwidth settings remain valid after you change the specifications of the instance.
  Migrate an instance across zones	If the instance uses the standard architecture, the bandwidth settings remain valid after you migrate the instance across zones.

Procedure

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 Configuration Information section, click Modify to the right of Maximum Internal Bandwidth.

   Note

   The first time you log on to the DAS console, follow the instructions to grant permissions to your account.

3. Turn on the Bandwidth Auto Scaling switch.

4. In the DAS console, configure the policy for bandwidth auto scaling and event subscription.

   1. Set the parameters for bandwidth auto scaling policy.

      Section	Parameter	Description
      Automatic Bandwidth Upgrade	Automatic Bandwidth Upgrade	Turn on the switch to enable the feature.
      	Average Bandwidth Usage ≥	The scale-up threshold. Select the threshold of average bandwidth usage for triggering an automatic scale-up. Valid values: 50% to 95%. Note The system compares the bandwidth usage of inbound traffic and that of outbound traffic, and takes the larger value as the Average Bandwidth Usage. The bandwidth of the instance can be increased by up to six times the default bandwidth of the instance type, with a cap at 192 MB/s. You can also view the message about this limit in the panel.
      	Observation Window	Select the length of the observation window. Unit: minutes. Note When the average bandwidth usage within the observation window is greater than or equal to the threshold, bandwidth auto scaling is triggered.
      Automatic Bandwidth Downgrade	Automatic Bandwidth Downgrade	Turn on the switch to enable the feature. Before you enable the feature, make sure that the Automatic Bandwidth Upgrade feature is enabled.
      	Average Bandwidth Usage ≤	The scale-down threshold. Select the threshold of average bandwidth usage for triggering an automatic scale-down. Valid values: 10% to 70%. The threshold must be at least 10% lower than the scale-up threshold. Note The system compares the bandwidth usage between inbound traffic and outbound traffic, and uses the larger value as the Average Bandwidth Usage.

5. Click OK.

   In the Tair console, the Bandwidth Auto Scaling switch is turned on, indicating that the feature is enabled.

6. Optional: Configure alerts to receive timely notifications about automatic bandwidth expansion or contraction for your database instance. You can follow the system prompts to complete the configuration.

   Note

   • If you have already configured an alert template for the instance, the alert configuration prompt will not appear.

   • If you need to manually set up alert templates and rules, see Configure alert templates and Configure alert rules.

   Expand to view detailed steps

   1. Select the system-recommended alert template. The system will add the Auto Scaling Events monitoring item.

   2. Select the Alert Contact Groups that should receive alert notifications.

   3. Click Submit Configuration and confirm the alert configuration in the dialog box that appears.