All Products
Search
Document Center

Tair (Redis® OSS-Compatible):SwitchInstanceHA

Last Updated:Jun 26, 2026

Performs a primary/secondary switchover (switches node roles). This operation can be used for disaster recovery drills and nearest access for applications in multi-zone deployment scenarios.

Operation description

Note

For more information about nearest access for applications in multi-zone deployment scenarios, see Scenario examples.

When you call this operation, the instance must be of the high-availability or dual-replica type.

Calling this operation has the following impacts:

  • After a node role switchover is triggered, the data node being switched enters a read-only state for a few seconds and experiences a transient connection. Make sure that your application has a reconnection mechanism.

  • While the instance is in the switching state, you cannot perform instance-level operations such as configuration changes or zone migration.

Try it now

Try this API in OpenAPI Explorer, no manual signing needed. Successful calls auto-generate SDK code matching your parameters. Download it with built-in credential security for local usage.

Test

RAM authorization

The table below describes the authorization required to call this API. You can define it in a Resource Access Management (RAM) policy. The table's columns are detailed below:

  • Action: The actions can be used in the Action element of RAM permission policy statements to grant permissions to perform the operation.

  • API: The API that you can call to perform the action.

  • Access level: The predefined level of access granted for each API. Valid values: create, list, get, update, and delete.

  • Resource type: The type of the resource that supports authorization to perform the action. It indicates if the action supports resource-level permission. The specified resource must be compatible with the action. Otherwise, the policy will be ineffective.

    • For APIs with resource-level permissions, required resource types are marked with an asterisk (*). Specify the corresponding Alibaba Cloud Resource Name (ARN) in the Resource element of the policy.

    • For APIs without resource-level permissions, it is shown as All Resources. Use an asterisk (*) in the Resource element of the policy.

  • Condition key: The condition keys defined by the service. The key allows for granular control, applying to either actions alone or actions associated with specific resources. In addition to service-specific condition keys, Alibaba Cloud provides a set of common condition keys applicable across all RAM-supported services.

  • Dependent action: The dependent actions required to run the action. To complete the action, the RAM user or the RAM role must have the permissions to perform all dependent actions.

Action

Access level

Resource type

Condition key

Dependent action

kvstore:SwitchInstanceHA

update

*All Resource

*

None None

Request parameters

Parameter

Type

Required

Description

Example

InstanceId

string

Yes

The instance ID. You can call DescribeInstances to query the instance ID.

r-bp1zxszhcgatnx****

NodeId

string

No

The ID of the data shard node. You can call DescribeRoleZoneInfo to obtain the CustinsId parameter. Separate multiple data shard node IDs with commas (,). To specify all nodes, enter all.

Note

This parameter is available and required only when the instance uses the cluster or read/write splitting architecture.

56****19,56****20

SwitchMode

integer

No

The execution time. Valid values:

  • 0: immediately. This is the default value.

  • 1: during the maintenance window.

Note

You can call ModifyInstanceMaintainTime to modify the maintenance window of the instance.

0

SwitchType

string

No

The switchover mode. Valid values:

  • ReliabilityPriority (default): Reliability is prioritized. The primary/secondary switchover is performed only when primary/secondary synchronization has no latency, which prevents data loss. In scenarios with heavy write workloads and persistent synchronization latency, this mode may cause the primary/secondary switchover to fail.

  • AvailablePriority: Availability is prioritized. The primary/secondary switchover is performed immediately regardless of primary/secondary latency, which may cause minor data loss.

Note

Evaluate your business requirements for data integrity and service availability before selecting a switchover mode.

Valid values:

  • AvailablePriority :

    AvailablePriority

  • ReliabilityPriority :

    ReliabilityPriority

ReliabilityPriority

SourceNodeId

string

No

The node ID of the original MASTER node in the shard.

52717408

TargetNodeId

string

No

The node ID of the target MASTER node after the switchover.

52717403

TargetShardName

string

No

The shard name of the instance.

r-2zegk3jyxxxwixfo6c-db-1

Response elements

Element

Type

Description

Example

object

RequestId

string

The request ID.

5D622714-AEDD-4609-9167-F5DDD3D1****

TaskId

string

674546459

Examples

Success response

JSON format

{
  "RequestId": "5D622714-AEDD-4609-9167-F5DDD3D1****",
  "TaskId": "674546459"
}

Error codes

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.