You can call this operation to apply for the read-write splitting address.

For a master instance that has read-only instances, you can apply for the read/write splitting address. The read/write splitting address does not affect the existing connection addresses of the master instance and its read-only instances, nor does it affect your applying for the intranet and Internet addresses.

When you call this operation, the instance must meet the following requirements:

  • The instance is in the running state.
  • The instance has at least one read-only instance.
  • The instance does not have an ongoing migration task.
  • This operation is applicable to the following database engine versions:
    • MySQL 5.6
    • SQL Server 2017 Cluster Edition


You can use API Explorer to perform debugging.

Request parameters

Parameter Type Required Example Description
Action String Yes AllocateReadWriteSplittingConnection

The operation that you want to perform. Set the value to AllocateReadWriteSplittingConnection.

DBInstanceId String Yes rm-uf6wjk5xxxxxxx

The ID of the master instance.

ConnectionStringPrefix String No

The prefix of the read/write splitting address. It must be unique and start with a letter. It contains at most 30 characters, including lowercase letters or hyphens (-).

Note By default, the prefix is "instance name + rw".
Port String No 3306

The read/write splitting port. Valid values:

  • MySQL: 3001 to 3999. Default value: 3306.
  • SQL Server: 1000 to 5999. Default value: 1433.
MaxDelayTime String No 30

The latency threshold. It ranges from 0 to 7,200. Default value: 30. Unit: seconds.

Note If a read-only instance reaches the latency threshold, read requests are no longer sent to the read-only instance.
NetType String No Intranet

The network type of the read/write splitting address. Valid values:

  • Internet.
  • Intranet (default value). The intranet type (classic network or VPC) is the same as the that of the master instance.
DistributionType String No Standard

The mode of read weight distribution. Valid values:

  • Standard: Read weights are distributed according to instance specifications.
  • Custom: Read weights are specified by you.
Weight String No {“Instanceid1“:”100”,”Instanceid2”:”200”}

The read weight distribution. Enter the read weights for the master instance and its read-only instances. It must be a multiple of 100. The maximum value is 10000. Format: {“Instanceid1“:”Weight”,”Instanceid2”:”Weight”...}.

  • This parameter is required if DistributionType is set to Custom.
  • This parameter is invalid if DistributionType is set to Standard.
AccessKeyId String No LTAIfCxxxxxxx

The AccessKey ID issued by Alibaba Cloud for users to access services.

Response parameters

Parameter Type Example Description
RequestId String 4C467B38-3910-447D-87BC-AC049166F216

The ID of the request.


Request example

&<Common request parameters>

Normal response examples

XML format


JSON format