[Notice] DDS 4.4 OBT Invitation

Quick Start

1. Open the Huawei Cloud official website.
2. Click Console in the upper right corner of the page and log in to the Huawei Cloud management console using your Huawei ID.
3. Click in the upper left corner of the page and choose Databases > Document Database Service.
4. In the upper right corner of the page, click Buy DB Instance.
5. Select your region and set Compatible MongoDB Version to 4.4. Set other configuration items as required. For details, see Quick Config and Custom Config.
   Figure 1 Configuration information
   

6. Click Next to create a DB instance for free.
7. After the instance is created, click its name on the Instances page and click Log In. You can log in to the instance through DAS. For details, see DAS User Guide. For details about other connection methods, see Connection Methods.
   Figure 2 Logging in to a DB instance
   

Notice on OBT

Huawei Cloud Service Level Agreement is not guaranteed for DDS instances during the OBT.

• Disclaimer

  You shall understand and agree that although the OBT service assures service availability and reliability, Huawei Cloud does not commit itself to the availability or reliability of any services during free trials. Huawei Cloud does not assume any responsibilities for your work or results generated by OBT services.

• Feedback

  Huawei Cloud is willing to cooperate with you to solve problems and is committed to continuously improving service quality. In the event of any problems, you can call the customer service telephone number available at our official website to report faults and receive technical support.

Recommendations

• What Is DDS?

  Huawei Cloud Document Database Service (DDS) is compatible with MongoDB and provides functions such as security audit, multi-account management, and point-in-time backup and restoration. It supports cluster, replica set, and single-node deployment architectures. For details, see What Is DDS?

• What's New in DDS 4.4?

  DDS 4.4 enhances existing capabilities and improves availability. The new features are as follows:

  • Mutable Shard Keys

    In DDS 4.2, you can change the shard key value, but you must migrate data across shards based on distributed transactions. This will increase performance overheads and is unable to prevent jumbo chunks and query hotpots. In DDS 4.4, you can run the refineCollectionShardKey command to add one or more suffix fields to an existing shard key to improve the distribution of existing data on chunks. The refineCollectionShardKey command has low performance overheads because this command does not involve any data migration.

  • Hedged Reads

    To shorten the response time, DDS 4.4 provides the hedged read feature. In a sharded cluster, the mongos nodes route a read request from a client to multiple replica set nodes of a shard and return results from the first respondent to the client.

  • Compound Hashed Shard Keys
    • In versions earlier than DDS 4.4, you can specify only the hash key with a single field. This may lead to uneven data distribution in collections across data shards.
    • DDS 4.4 supports compound hashed indexes. You can specify a single hashed field in compound indexes as the prefix or suffix field.
    • The flexible compound hashed indexes have many advantages and simplify the database table design. For example, a collection uses a monotonically increasing value as the shard key. Data from the latest access request is also written to the same shard, which results in a large shard and uneven distribution of data across shards.
    • For more information about new features, see DDS 4.4 Function Overview.
    • For details about DDS features and MongoDB compatibility, see Compatibility Details.