When you upgrade an Active-Active (CRDB) database, you can also upgrade the CRDB protocol version and feature version.

CRDB protocol version guidelines

Starting with version 5.4.2, a new CRDB protocol version helps support Active-Active features.

The new CRDB protocol is backward compatible, which means v5.4.2 CRDB instances can understand write operations from instances using the the earlier CRDB protocol.

After you upgrade the CRDB protocol on one instance, non-upgraded instances cannot receive write updates from the upgraded instance.

The upgraded instance receives updates from upgraded and non-upgraded instances.

When upgraded to the latest protocol version, upgraded instances automatically receive any missing write operations.

Follow these upgrade guidelines:

  • Upgrade all instances of a specific CRDB within a reasonable time frame to avoid temporary inconsistencies between the instances.

  • Make sure that you upgrade all instances of a specific CRDB before you do global operations on the CRDB, such as removing instances and adding new instances.

  • As of v6.0.20, protocol version 0 is deprecated and support will be removed in a future version.

  • To avoid upgrade failures, update all Active-Active databases to the latest protocol version before upgrading Redis Enterprise Software to v6.0.20 or later.

Feature version guidelines

Starting with version 5.6.0, a new feature version (also called a feature set version) helps support new Active-Active features.

When you update the feature version for an Active-Active database, the feature version is updated for all database instances.

Follow these upgrade guidelines:

  • As of v6.0.20, feature version 0 is deprecated and support will be removed in a future version.

  • To avoid upgrade failures, update all Active-Active databases to the latest protocol version before upgrading Redis Enterprise Software to v6.0.20 or later.

Upgrade Active-Active database instance

To upgrade an Active-Active database (CRDB) instance:

  1. Upgrade Redis Enterprise Software on each node in the clusters where the Active-Active instances are located.

  2. To see the status of your Active-Active instances, run:

    rladmin status
    

    The statuses of the Active-Active instances on the node can indicate:

    • OLD REDIS VERSION
    • OLD CRDB PROTOCOL VERSION
    • OLD CRBD FEATURESET VERSION

    crdb-upgrade-node

  3. To upgrade each Active-Active instance, including the Redis version and CRDB protocol version, run:

    • To upgrade a database without modules:

      rladmin upgrade db <database_name | database_ID>
      
    • If the database has modules enabled and new module versions are available in the cluster, run rladmin upgrade db with additional parameters to upgrade the module versions when you upgrade the database. See Upgrade modules for more details.

    If the protocol version is old, read the warning message carefully and confirm.

    crdb-upgrade-protocol

    The Active-Active instance uses the new Redis version and CRDB protocol version.

    Use the keep_crdt_protocol_version option to upgrade the database feature version without upgrading the CRDB protocol version.

    If you use this option, make sure that you upgrade the CRDB protocol soon after with the rladmin upgrade db command.

    You must upgrade the CRDB protocol before you update the CRDB feature set version.

  4. If the feature set version is old, you must upgrade all of the Active-Active instances. Then, to update the feature set for each active-active database, run:

    crdb-cli crdb update --crdb-guid <CRDB-GUID> --featureset-version yes
    

    You can retrieve the <CRDB-GUID> with the following command:

    crdb-cli crdb list
    

    Look for the fully qualified domain name (CLUSTER-FDQN) of your cluster and use the associated GUID:

    CRDB-GUID                             NAME    REPL-ID  CLUSTER-FQDN
    700140c5-478e-49d7-ad3c-64d517ddc486  aatest  1        aatest1.example.com
    700140c5-478e-49d7-ad3c-64d517ddc486  aatest  2        aatest2.example.com
    
  5. Update module information in the CRDB configuration using the following command syntax:

    crdb-cli crdb update --crdb-guid <guid> --default-db-config \
    '{ "module_list": 
      [
        { 
          "module_name": "<module1_name>",
          "semantic_version": "<module1_version>" 
        },
        { 
          "module_name": "<module2_name>",
          "semantic_version": "<module2_version>" 
        }
      ]}'
    

    For example:

    crdb-cli crdb update --crdb-guid 82a80988-f5fe-4fa5-bca0-aef2a0fd60db --default-db-config \
    '{ "module_list": 
      [
        {
          "module_name": "search",
          "semantic_version": "2.4.6"
        },
        {
          "module_name": "ReJSON",
          "semantic_version": "2.4.5"
        }
      ]}'