Updated on 2025-06-11 GMT+08:00

What's New

The tables below describe the features and corresponding documentation updates released in each Distributed Database Middleware (DDM) version. New features will be successively launched.

April 2025

No.

Feature

Description

Phase

Document

1

Kernel versions of DDM instances can be manually changed.

You can manually upgrade or downgrade the kernel version of an instance immediately or at a scheduled time.

-

-

June 2024

No.

Feature

Description

Phase

Document

1

The ddl_flowcontrol_threshold parameter has been added to the parameter template.

You can modify the parameter in the parameter template to control the number of DDL operations executed within 1 hour.

-

-

April 2024

No.

Feature

Description

Phase

Document

1

A metric for a DDM instance is added.

You can use APIs provided by Cloud Eye to query the metrics generated for DDM. You can check the ddm_global_sequence_threshold_exceeded_count metric for a DDM instance.

-

-

January 2024

No.

Feature

Description

Phase

Document

1

Added a check for maximum number of physical tables on the shard configuration check page.

When you add shards, each data record in the source table will be rerouted to a new physical table. It takes a long time for sharding if there are too many physical tables. Check whether the number of physical tables on each node exceeds the upper limit.

-

-

October 2023

No.

Feature

Description

Phase

Document

1

Session management is supported.

If the maximum number of connections for a DDM instance has been reached and the instance cannot be logged in to, you can view and kill unnecessary sessions using the session management function. DDM allows you to view connection sessions between the DDM instance and applications, or between the DDM instance and its associated data nodes (RDS for MySQL instances).

-

-

September 2023

No.

Feature

Description

Phase

Document

1

Dedicated execution node type

If you select Dedicated for Execution Node Type, the execution node will be dedicated to configuring shards, so shard configuration is faster.

-

-

March 2023

No.

Feature

Description

Phase

Document

1

Upgrading and rolling back kernel versions

A DDM kernel version usually consists of four digits, for example, 3.0.8.x. The first three digits indicate the major version number, for example, 3.0.8. A series of minor versions will be released for each major version. The preferred version of this DDM series is a recommended minor version. It is also the latest and the most stable version. For DDM instances of the same major version, upgrading the kernel version to this preferred version is a minor version upgrade. This operation involves issue rectification and has a low risk of syntax incompatibility. You are advised to upgrade your instance to the preferred version.

-

-

February 2023

No.

Feature

Description

Phase

Document

1

Manually enabling read/write splitting

DDM optimizes its read/write splitting function. In earlier versions, read/write splitting is automatically enabled after read replicas are added. From this version on, read/write splitting needs to be manually enabled after read replicas are added, and you can set read weights for your primary instance and read replicas.

-

-

January 2023

No.

Feature

Description

Phase

Document

1

Online DDL operations

DDM supports online DDL operations, including adding, deleting, and modifying fields, setting default values, and modifying character sets and table names.

-

-

September 2022

No.

Feature

Description

Phase

Document

1

Service rollout

DDM is a MySQL-compatible, distributed middleware service designed for relational databases. It can resolve distributed scaling issues to break through capacity and performance bottlenecks of traditional databases, helping handle highly concurrent access to massive volumes of data. DDM provides various functions, including horizontal sharding, flexible shard configuration, distributed transactions, data import and export, high SQL compatibility, read/write splitting, global sequence, and online monitoring.

Commercial use

Documentation