Help Center/ TaurusDB/ User Guide/ Instance Management/ Configuration Changes/ Changing a Single DB Instance to a Cluster DB Instance
Updated on 2025-08-21 GMT+08:00
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Changing a Single DB Instance to a Cluster DB Instance

After a single DB instance is created, you can upgrade it to a cluster DB instance by adding read replicas to it.

Constraints

Once a single DB instance is changed to a cluster DB instance, it cannot be rolled back to a single DB instance.

Billing

Table 1 Billing

Billing Mode

Operation

Impact on Price

Yearly/Monthly

Single to cluster

You need to pay for the difference in price based on the remaining period.

The following prices are for reference only. The actual prices are displayed on the console.

Suppose you purchased a one-month TaurusDB single instance (instance specifications: dedicated, 2 vCPUs | 8 GB; storage: DL6, 10 GB) in CN-Hong Kong on April 1, 2025. The instance price was $151 USD per month.

On April 15, 2025, you changed the instance type from single to cluster. The instance price was $296 USD per month.

Price difference = Price for the cluster instance x Remaining period – Price for the single instance x Remaining period

The remaining period is the remaining days of each calendar month divided by the maximum number of days in each calendar month.

In this example, the remaining period and price difference are calculated as follows: Remaining period = 15 (Remaining days in April)/30 (Maximum number of days in April) = 0.5. Price difference = $296 USD x 0.5 – $151 USD x 0.5 = $72.5 USD

Pay-per-use

Single to cluster

The cluster DB instance is billed by hour. For details, see Product Pricing Details.

Procedure

  1. Log in to the management console.
  2. Click in the upper left corner and select a region and project.
  3. Click in the upper left corner of the page and choose Databases > TaurusDB.
  4. On the Instances page, locate the row containing the target single instance, and choose More > Create Read Replica in the Operation column.

    Figure 1 Selecting a single instance

    Alternatively, click the instance name to go to the Basic Information page. In the upper right corner of the page, click and choose Create Read Replica.

  5. On the displayed page, set the number of read replicas.

    Figure 2 Setting the number of read replicas

  6. Click Next.
  7. Confirm the information and click Submit.

    On the Instances page, check that the instance status is Creating read replicas. You can also go to the Task Center page to view the task progress.

    Figure 3 Creating read replicas

  8. After the read replicas are created, check that the instance status becomes Available and the instance type becomes Cluster.

    Figure 4 Change succeeded

Parent Topic: Configuration Changes