ApsaraDB for Redis supports the subscription and pay-as-you-go billing methods. You can change the billing method from pay-as-you-go to subscription. The pay-as-you-go and subscription billing methods allow you to modify the specifications of an instance.

Background information

The pay-as-you-go and subscription billing methods allow you to upgrade or downgrade instances anytime. You can upgrade a non-cluster instance to a cluster instance or downgrade a cluster instance to a non-cluster instance. To change the type and specifications of an instance, you must change the instance type prior to the specifications. For example, if you want to change an 8 GB standard instance to a 4 GB cluster instance, you must first change the standard instance to a cluster instance. Then, downgrade the capacity of the cluster instance from 8 GB to 4 GB.

Notice
  • Before you change a non-cluster instance to a cluster instance, you must evaluate how the command limits of the cluster instance affect your workloads. For more information, see Limits on the commands supported by cluster instances.
  • After you change a non-cluster instance to a cluster instance or change a cluster instance to a non-cluster instance, the original alert settings become invalid. In this case, you must reconfigure the alert settings. For more information, see Alert settings.

The duration of a specification change is based on multiple factors such as the network conditions, task queue size, and data volume. We recommend that you change the specifications during off-peak hours. Make sure that your applications can be automatically reconnected.

Pricing

For more information, see Specification changes.

Impacts

  • When you change the specifications of an instance, the instance may be disconnected one or two times. Each disconnection lasts for 30 seconds or less.
    Note For Luttece clients, the instance may be disconnected for 2 to 10 minutes.
  • If you set Switching Time to Switching during serviceable time when you change the specifications of an instance, the instance is changed in the next maintenance period. For more information, see Set a maintenance window.
    Notice The preceding options specify the time when the specifications of an instance are changed. Full data synchronization starts immediately after the payment for changing specifications is completed. To avoid response latency and network jitter caused by the fork system call in full data synchronization, we recommend that you change the instance specifications during off-peak hours.
  • To synchronize incremental data between the new instance and the original instance and avoid dual-write caused by the DNS cache, the instance becomes read-only for less than 1 minute during the change. This ensures data consistency between the new instance and the original instance.
  • To ensure higher performance and stability, the system upgrades the minor version of the instance to the latest version when it changes the specifications of the instance.

Limits

If the ApsaraDB for Redis instance uses a cluster architecture, take note of the following limits when you change the specifications:

  • You are not allowed to reduce the number of shards.
  • If the private endpoint is enabled for a cluster instance of ApsaraDB for Redis, you can only double the current number of shards for the instance. For example, if the original ApsaraDB for Redis instance has two shards, you can scale the instance only to only four shards. Eight shards are not supported. If you want to scale the instance from two shards to eight shards, you can use one of the following methods:
    • You can first scale the instance from two shards to four shards. Then, scale the instance from four shards to eight shards.
    • You can also release the private endpoint and then change the specifications. In this case, you can directly scale the instance to eight shards. For more information, see Release a private endpoint.

Procedure for pay-as-you-go instances

  1. Log on to the ApsaraDB for Redis console.
  2. On the top of the page, select the region where the instance is deployed.
  3. On the Instance List page, click the Instance ID of the instance.
  4. In the upper-right corner of the page, click Change Configurations .
  5. On the Update page, configure the specifications and click Pay.

    If the instance is scaled, a message appears, which indicates that the operation is successful. Then, you are charged for the pay-as-you-go instance based on the new specifications in the current billing cycle.

Procedure for subscription instances

  1. Log on to the ApsaraDB for Redis console.
  2. On the top of the page, select the region where the instance is deployed.
  3. On the Instance List page, click the Instance ID of the instance.
  4. In the upper-right corner of the page, click Upgrade or Downgrade.
    Note If the price of the new specifications is higher than the price of the current specifications, select Upgrade. If the price of the new specifications is lower than the price of the existing specifications, select Downgrade. For example, the price of an 8 GB read/write splitting instance with five read replicas is higher than the price of a 16 GB cluster instance. If you want to scale a 16 GB cluster instance to an 8 GB read/write splitting instance with five read replicas, you must upgrade the instance.
  5. On the Update page, configure the specifications and click Pay.
  6. Complete the payment.

Related API operations

API operation Description
ModifyInstanceSpec Changes the specifications of an ApsaraDB for Redis instance.