ApsaraDB for MongoDB allows you to change configurations to meet your needs in most scenarios. It also provides solutions to the configuration items that you cannot change.

For more information about instance specifications, see Instance types.

For more information about correspondence and restrictions between versions and storage, see MongoDB versions and storage engines.
Note For more information about precautions and procedure for version upgrade, see Upgrade the database version of an ApsaraDB for MongoDB instance.

Standalone instances

Item Configuration change supported Description
Specifications Yes For more information, see Change the configuration of a standalone or replica set instance.
Storage space Yes For more information, see Change the configuration of a standalone or replica set instance.

If the billing method is subscription, you cannot downgrade the storage space. You must perform the following operations:

  1. Create a pay-as-you-go standalone instance and select the required storage space. For more information, see Create a standalone ApsaraDB for MongoDB instance.
    Note The storage space of the new instance must be larger than the occupied storage space in the original instance.
  2. Use DTS to migrate data from the original instance to the new instance. For more information, see Overview.
  3. Test and verify the new instance. If it runs normally, switch business to the new instance.
    Note If a long period of use, we recommend that you switch from pay-as-you-go to subscription. This billing method is more cost-effective than pay-as-you-go. The longer the subscription period, the higher the discount.
  4. If the original instance is no longer needed, you can manually release the pay-as-you-go instance or submit a ticket to release the subscription instance.
Number of nodes No

You cannot change the number of nodes, architecture, and storage engine for a standalone instance. You must perform the following operations:

  1. Create a pay-as-you-go instance. Select the required number of nodes, architecture, and storage engine.
    Note
    • To increase the number of nodes, you must create a replica set instance.
    • The storage space of the new instance must be larger than the occupied storage space in the original instance.
  2. Use DTS to migrate data from the original instance to the new instance. For more information, see Overview.
  3. Test and verify the new instance. If it runs normally, switch business to the new instance.
    Note If a long period of use, we recommend that you switch from pay-as-you-go to subscription. This billing method is more cost-effective than pay-as-you-go. The longer the subscription period, the higher the discount.
  4. If the original instance is no longer needed, you can manually release the pay-as-you-go instance or submit a ticket to release the subscription instance.
Instance architecture
Storage engines

Replica set instances

Item Configuration change supported Description
Number of nodes Yes For more information, see Change the number of nodes for a replica set instance.
Specifications Yes For more information, see Change the configuration of a standalone or replica set instance.
Storage space Yes For more information, see Change the configuration of a standalone or replica set instance.

If the billing method is subscription, you cannot downgrade the storage space. You must perform the following operations:

  1. Restore data to a new ApsaraDB for MongoDB instance by point in time Create a pay-as-you-go standalone instance and select the required storage space.
    Note The storage space of the new instance must be larger than the occupied storage space in the original instance.
  2. Test and verify the new instance. If it runs normally, switch business to the new instance.
    Note If a long period of use, we recommend that you switch from pay-as-you-go to subscription. This billing method is more cost-effective than pay-as-you-go. The longer the subscription period, the higher the discount.
  3. If the original instance is no longer needed, you can manually release the pay-as-you-go instance or submit a ticket to release the subscription instance.
Instance architecture No

You cannot change the architecture and storage engine of a replica set instance. You must perform the following operations:

  1. Create a pay-as-you-go instance. Select the required architecture and storage engine.
    Note The storage space of the new instance must be larger than the occupied storage space in the original instance.
  2. Use DTS to migrate data from the original instance to the new instance. For more information, see Overview.
  3. Test and verify the new instance. If it runs normally, switch business to the new instance.
    Note If a long period of use, we recommend that you switch from pay-as-you-go to subscription. This billing method is more cost-effective than pay-as-you-go. The longer the subscription period, the higher the discount.
  4. If the original instance is no longer needed, you can manually release the pay-as-you-go instance or submit a ticket to release the subscription instance.
Storage engines

Sharded cluster instances

You can change the specifications and storage space of a sharded cluster instance.
Note You cannot change the architecture and storage engine of a sharded cluster instance. Creating a new instance will cause a long-period shutdown and have a great impact on the business. Therefore, we do not recommend this method.
Component Item Description
Mongos node Specifications For more information, see Change the configuration of a sharded cluster instance.
Shard node Specifications For more information, see Change the configuration of a sharded cluster instance.

If the billing method is subscription, you cannot downgrade the storage space. You must perform the following operations:

  1. Restore data to a new ApsaraDB for MongoDB instance by point in time Create a pay-as-you-go standalone instance and select the required storage space.
    Note The storage space of the new instance must be larger than the occupied storage space in the original instance.
  2. Test and verify the new instance. If it runs normally, switch business to the new instance.
    Note If a long period of use, we recommend that you switch from pay-as-you-go to subscription. This billing method is more cost-effective than pay-as-you-go. The longer the subscription period, the higher the discount.
  3. If the original instance is no longer needed, you can manually release the pay-as-you-go instance or submit a ticket to release the subscription instance.
Storage space
Configserver node Specifications and storage space A Configserver node uses a fixed three-node replica set architecture. By default, 1 core, 2 GB memory, and 20 GB storage space are selected. You cannot change these items.