Cache for Redis provides blue-green deployment capabilities, allowing you to achieve zero-downtime, low-risk, and fully verifiable major database version upgrades. This topic describes the procedures for upgrading major versions using blue-green deployment.

Prerequisites

Instances needed to upgrade major versions using blue-green deployment must meet the following requirements:

The instance's database version is not Redis 7.0.

The instance status is Running. For more details, refer to Instance status.

The instance does not use additional bandwidth. If additional bandwidth is in use, cancel it first. For specific procedures, refer to Modifying bandwidth.

The instance with sharding cluster enabled has not applied for direct connection address. If a direct connection address has been applied for, release it first. For specific procedures, refer to Releasing direct connection addresses.

Currently, only support creating Pay-as-you-go green instances. Therefore, before creating green instance, ensure that the total value of your account balance (that is, cash balance) and vouchers must be at least CNY 100. For more information, refer to Pay-as-you-go.

Precautions

A single instance can have at most one ongoing blue-green deployment process each time.

During the process of upgrading an instance's major version using the blue-green deployment feature, both blue and green instances are only allowed to perform information viewing operations, for example, Viewing instance information, Viewing monitoring data.

Upgrade process

When Cache for Redis upgrades major version using blue-green deployment feature, it mainly involves 3 main processes: creating green instance, testing and verification, and blue-green switch. The following table summarizes the detailed descriptions of each process for your reference.

Upgrade process	Process description
Create green instance	To perform a major version upgrade using blue-green deployment, you must first create a green instance. This method enables database updates to be applied with brief, predictable downtime. The blue-green deployment model not only reduces risks during database updates (such as major or minor engine version upgrades) but also further shortens the associated service interruption.
Test verification	To ensure stable operation after upgrade, go to green instance's details page, obtain connection address, connect to instance and conduct thorough testing. You can refer to the following suggestions for testing: Test scope recommendation: Prioritize validating core business scenarios (for example, data read/write, transaction execution, key expiration policies). Focus on high-concurrency, high-traffic operations consistent with production environment to confirm green instance functionality and performance meet expectations. Data consistency verification: Compare key data (for example, quantity and value integrity of core business keys) between blue (original instance) and green (new instance) to ensure complete and accurate data synchronization.: Compare key data between the blue (original instance) and green (new instance) ends (e.g., the number of core business keys, value integrity) to ensure that data synchronization is complete and accurate, with no omissions or discrepancies. Issue reporting: If you encounter functional anomalies, performance degradation, or data inconsistencies during testing, submit a ticket to contact technical support. We will assist in identification and resolution to prevent impact on upgrade schedule. Monitor memory usage: During testing, closely monitor the memory usage of the blue and green instances to prevent data synchronization anomalies caused by excessive test data in the green instance. For more details on memory usage, refer to Monitoring and alerts.
Blue-green switch	After thoroughly testing and verifying the green instance has no issues, you can choose appropriate time to perform the blue-green switch operation based on your business needs: After blue-green switch completes, only business data and Redis major version are swapped between blue and green instances, ensuring seamless business access. Blue instance (original instance) configurations including metadata, connection method, allowlist, and account information remain unchanged. During switching, the database may experience brief disconnections (1~3 times) or enter read-only status for seconds. Operate with caution. It is recommended to perform the switch operation during off-peak business hours and ensure the application has an automatic reconnection mechanism to minimize the impact of the operation on your business. If write operations were performed on the green instance, restart the blue-green deployment process to ensure data integrity and avoid inconsistency risks. If business assessment determines new data in green instance has no impact and is acceptable, redeployment is unnecessary and blue-green switch can proceed directly.

Blue-green deployment status

The following table summarizes the possible statuses in the blue-green deployment process, along with relevant explanations and impacts for your reference.

Blue-green deployment status	Status code	Triggering operation	Description or impact
Initializaing	INIT	After creating the blue-green deployment task, the system starts verifying source instance (that is, blue instance) related information and enters the Initializaing status.	At this time, both blue and green instances are Blue-green deployment in progress, and both blue and green instances are only allowed to perform information viewing operations, such as Viewing instance information and Viewing monitoring data.
Creating green instance	PROVISIONING	After the blue-green deployment task is successfully created, the creation of the target instance (that is, the green instance) begins.
Green instance running	AVAILABLE	The green instance has been created and is in the running status, ready to enter the data synchronization phase.
Data synchronizing	DATA_SYNCHRONIZING	After the green instance is in the running status, the system automatically triggers a data synchronization task, and the status will switch to Data synchronizing.
Switchable	SWITCHOVER_AVAILABLE	After data synchronization is complete, blue-green deployment enters the Switchable status. At this point, you can initiate the blue-green switch operation after thorough testing and verification.
Switching	SWITCHOVER_IN_PROGRESS	After initiating the immediate blue-green deployment switch task, the status will change to Switching.
Waiting for switch	SWITCHOVER_PENDING	When you choose to execute during the maintenance period, the blue-green deployment will enter the Waiting for switch status, which will persist until the task is complete. For the method to set the maintenance period, refer to Setting maintenance period.
Switch failed	SWITCHOVER_FAILED	When an exception occurs (such ashealth check failure, write failure, or internal error) during the switchover leading to an incomplete switchover, the status changes to Switch failed.
Deleting	DELETING	After canceling the blue-green deployment task, the status will change to Deleting.
Switch completed	SWITCHOVER_COMPLETED	After the blue and green instances are switched, the blue-green deployment task will enter the Switch completed status.	The status of both blue and green instances is Running. You can perform view, change, and modify actions on the blue and green instances.
Deletion completed	DELETE_COMPLETED	Blue-green deployment has been canceled, the corresponding blue-green deployment task will end, and the status will change to Deletion completed.

Billing instructions

Related costs are incurred when creating green instance. For instance billing details, refer to Billing overview.

Procedure

Log in to the Redis console.

In the upper-left corner of the top menu bar, select the project and region to which the instance belongs.

On the Instances page, click the target instance name.

In the Configuration area of the Summary tab, click Upgrade major version after Database version.

In the pop-up panel, follow the procedure to complete the following operations.

Step 1: Create green instance

Step 2: Test verification

Step 3: Blue-green switch

Click Create green instance.

In the pop-up panel, set the following parameters for the green instance based on your business requirements.

Parameters			Description
Blue instance configuration			Confirm the database version and instance specifications (including node specifications, quantity, and shard quantity) of the blue instance.
Basic information	Green instance name	Set the name of the green instance. The name must meet the following requirements: It cannot start with a number or hyphen (-). It can only contain Chinese characters, letters, digits, underscores (_), and hyphens (-). The length should be 1 to 128 characters. tip If the name of the green instance is not set, <blue instance name>-green-<six-digit random code> will be used as its default instance name. For example, if the blue instance name is redistest, the default name of the green instance created for it might be redistest-green-b4bf10. The instance name for Cache for Redis cannot exceed 128 characters, and -green-<six-digit random code> occupies a fixed 13 characters. Therefore, to fit the total length limit, the <blue instance name> part of the green instance name will only use the first 115 characters of the blue name.
Specification configuration	Database version	Set the database version for the green instance. tip The database version of the green instance must be greater than that of the blue instance. For example, if the database version of the blue instance is 5.0, then the database version of the green instance can be 6.0 or 7.0.
Specification configuration		Instance specification	No configuration required. The instance specifications of the green instance (including node specifications, quantity, and shard quantity) are consistent with those of the blue instance.
Billing method			Set the billing method for the green instance. Currently, only Pay-as-you-go is supported.

In the lower-right corner of the page, click Confirm order.

On the Confirm configuration page, first confirm the configuration information of the green instance, read and check the service terms, then in the lower-right corner of the page, click Create green instance.

tip

After clicking Create green instance, you will be automatically redirected to the Summary page of the blue instance, and the instance status will change to Blue-green deployment in progress.

Subsequent operations

After completing the major version upgrade using blue-green deployment and verifying that there are no issues with the upgraded instance, delete the green instance promptly to avoid resource waste. For specific procedures, refer to Deleting pay-as-you-go instance.

Relevant APIs

API	Description
CreateBlueGreenDeployment	Call the CreateBlueGreenDeployment API to create blue-green deployment task.
DescribeBlueGreenDeployments	Call the DescribeBlueGreenDeployments API to query blue-green deployment task details for target Redis instance.
SwitchoverBlueGreenDeployment	Call the SwitchoverBlueGreenDeployment API to perform blue-green deployment switch for target Redis instance.
DeleteBlueGreenDeployment	Call the DeleteBlueGreenDeployment API to cancel blue-green deployment task for target Redis instance.