All Products
Document Center

ApsaraDB RDS:AllocateReadWriteSplittingConnection

Last Updated:May 29, 2023

You can call the AllocateReadWriteSplittingConnection operation to apply for a read/write splitting endpoint for an ApsaraDB RDS instance.

Operation Description

If read-only instances are attached to a primary ApsaraDB RDS for SQL Server instance, you can call this operation to apply for a unified read-only routing endpoint for the primary instance. After you apply for a read-only routing endpoint for a primary instance, the existing endpoints of the primary instance and its read-only instances remain valid. In addition, you can still apply for internal and public endpoints.

Before you call this operation, make sure that the following requirements are met:

  • If the instance runs MySQL, the instance uses a shared proxy.

  • The instance is in the Running state.

  • Read-only instances are attached to the primary instance.

  • The instance does not have an ongoing Data Transmission Service (DTS) migration task.

  • The instance runs one of the following database versions and RDS editions:

    • SQL Server (cluster edition)
    • MySQL 5.7 on RDS High-availability Edition with local SSDs
    • MySQL 5.6

Authorization information

The following table shows the authorization information corresponding to the API. The authorization information can be used in the Action policy element to grant a RAM user or RAM role the permissions to call this API operation. Description:

  • Operation: the value that you can use in the Action element to specify the operation on a resource.
  • Access level: the access level of each operation. The levels are read, write, and list.
  • Resource type: the type of the resource on which you can authorize the RAM user or the RAM role to perform the operation. Take note of the following items:
    • The required resource types are displayed in bold characters.
    • If the permissions cannot be granted at the resource level, All Resources is used in the Resource type column of the operation.
  • Condition Key: the condition key that is defined by the cloud service.
  • Associated operation: other operations that the RAM user or the RAM role must have permissions to perform to complete the operation. To complete the operation, the RAM user or the RAM role must have the permissions to perform the associated operations.
OperationAccess levelResource typeCondition keyAssociated operation
  • RDS
  • rds:ResourceTag

Request parameters


The ID of the primary instance. You can call the DescribeDBInstances operation to query the ID of the instance.


The prefix of the read-only routing endpoint. The prefix must be unique. It can be up to 30 characters in length and can contain lowercase letters and hyphens (-). It must start with a lowercase letter.

NoteThe default prefix consists of the name of the primary instance followed by the letters rw.

The port that is associated with the read-only routing endpoint. Valid values: 1000 to 5999. Default value: 1433.


The threshold of the latency that is allowed on the read-only instances. Valid values: 0 to 7200. Default value: 30. Unit: seconds.

NoteIf the latency on a read-only instance exceeds the specified threshold, ApsaraDB RDS does not forward read requests to the read-only instance.

The network type of the read-only routing endpoint. Valid values:

  • Internet: Internet
  • Intranet: internal network
NoteThe default value is Intranet. Make sure that the network type of the read-only routing endpoint is the same as that of the primary instance.

The method that is used to assign read weights. Valid values:

  • Standard: ApsaraDB RDS automatically assigns read weights to the primary and read-only instances based on the specifications of these instances.
  • Custom: You must manually assign a read weight to each instance.

The read weights of the primary instance and its read-only instances. The read weight is increased in increments of 100. The maximum value is 10000.

  • For ApsaraDB RDS instances, the value of this parameter is in the following format: {"<ID of the read-only instance >":<Weight>,"master":<Weight>,"slave":<Weight>}.
  • For ApsaraDB MyBase instances, the value of this parameter is in the following format: [{"instanceName":"<ID of the primary instance>","weight":<Weight>,"role":"master"},{"instanceName":"<ID of the primary instance>","weight":<Weight>,"role":"slave"},{"instanceName":"<ID of the read-only instance>","weight":<Weight>,"role":"master"}]
  • If you set the DistributionType parameter to Custom, you must also specify this parameter.
  • If you set the DistributionType parameter to Standard, this parameter is invalid.
  • {"rm-bp1**********":800,"master":400,"slave":400}

    Response parameters


    The ID of the request.



    Sample success responses


      "RequestId": "4C467B38-3910-447D-87BC-AC049166F216"

    Error codes

    For a list of error codes, visit the Service error codes.

    Change history

    Change timeSummary of changesOperation
    2022-06-23API Description Update
    Change itemChange content
    API DescriptionAPI Description Update