ApsaraDB for Redis supports the subscription and pay-as-you-go billing methods. Both billing methods allow you to change the specification of your 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 specification of an instance, you must change the instance type before you change the specification. 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 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 specifications during off-peak hours. Make sure that your applications can automatically reconnect to instances.

Billing

For more information, see Specification changes.

Precautions

  • When you change the specification of an instance, the instance may experience transient connections one or two times. Each transient connection lasts 30 seconds or less.
    Note For Luttece clients, the instance may experience transient connections that last 2 to 10 minutes.
  • If you set Switching Time to Switch Within Maintenance Window when you change the specification of an instance, the instance specification is changed in the next maintenance window, and the instance experiences transient connections.
    Notice The preceding parameter specifies the time when the specification of an instance is changed. Full data synchronization starts immediately after the payment for a specification change is completed. To reduce response latency and network jitter caused by the fork system call during full data synchronization, we recommend that you change 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 an instance to the latest version when it changes the specification of the instance.

Limits

If the direct connection 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 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 direct connection endpoint and then change the specification. In this case, you can directly scale the instance to eight shards. For more information, see Release a direction connection endpoint.

Procedure for pay-as-you-go instances

  1. Log on to the ApsaraDB for Redis console.
  2. In the top navigation bar of the page, select the region where the instance is deployed.
  3. On the Instances page, click the ID of the instance.
  4. In the upper-right corner of the page, click Change Configurations .
  5. On the Upgrade/Downgrade page, select a specification 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 specification in the current billing cycle.

Procedure for subscription instances

  1. Log on to the ApsaraDB for Redis console.
  2. In the top navigation bar of the page, select the region where the instance is deployed.
  3. On the Instances page, click the ID of the instance.
  4. In the upper-right corner of the page, click Upgrade or Downgrade.
    Note If the price of the new specification is higher than the price of the current specification, select Upgrade. If the price of the new specification is lower than the price of the existing specification, 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 Upgrade/Downgrade page, select a specification and click Pay.
  6. Complete the payment.

API operations

Operation Description
ModifyInstanceSpec Changes the specification of an ApsaraDB for Redis instance.