All Products
Search
Document Center

Data Transmission Service:Configure one-way data synchronization between ApsaraDB for Redis instances across Alibaba Cloud accounts

Last Updated:Oct 27, 2023

You can use Data Transmission Service (DTS) to perform one-way data synchronization between ApsaraDB for Redis instances that belong to different Alibaba Cloud accounts. This feature is suitable for scenarios such as resource migration or merging across Alibaba Cloud accounts and business architecture adjustment.

Prerequisites

  • If the source ApsaraDB for Redis instance is a Community Edition instance, the engine version is 4.0 or 5.0. If the source ApsaraDB for Redis instance is an Enhanced Edition (Tair) instance, the engine version is 5.0.

    Note

    The engine version of the destination ApsaraDB for Redis instance can be 4.0 or 5.0. The engine version of the destination ApsaraDB for Redis instance must be the same as or later than that of the source ApsaraDB for Redis instance. Before you synchronize data between two ApsaraDB for Redis instances that use different engine versions, check the compatibility of the two versions. For example, you can create a destination ApsaraDB for Redis instance that adopts the pay-as-you-go billing method to verify the compatibility between the source and destination instances. Then, you can release this instance or change the billing method of the instance to subscription.

  • The source or destination instance is a cluster, standard, or read/write splitting classic instance.

  • The source or destination instance is a standard cloud-native instance. A cluster cloud-native instance cannot be configured as the source or destination instance.

  • The source instance is deployed in a virtual private cloud (VPC). If the source ApsaraDB for Redis instance is deployed in the classic network, you can change the network type to VPC. For more information, see Change the network type from classic network to VPC.

  • SSL encryption is disabled for the source instance. For more information, see Configure SSL encryption.

  • The available storage space of the destination instance is larger than the total size of the data in the source instance.

  • To ensure compatibility between the source and destination instances, if an ApsaraDB for Redis Enhanced Edition (Tair) instance is configured as the source instance, the destination instance must be an ApsaraDB for Redis Enhanced Edition (Tair) instance. This is because ApsaraDB for Redis Enhanced Edition (Tair) is integrated with more Redis modules than ApsaraDB for Redis Community Edition.

  • The appendonly parameter is set to yes if a persistent memory-optimized instance is configured as the source instance.

  • The source instance is not a storage-optimized ApsaraDB for Redis Enhanced Edition (Tair) instance. A storage-optimized ApsaraDB for Redis Enhanced Edition (Tair) instance can be used only as the destination instance.

Background information

In this example, two ApsaraDB for Redis instances are created by different Alibaba Cloud accounts. You want to synchronize data from the instance of Account A to the instance of Account B. The following figure shows the architecture of the synchronization solution.Redis跨账号迁移架构图

The following table describes how to configure a one-way data synchronization task for this scenario.

Step

Description

1. Use Account A that owns the source instance to log on to the Resource Access Management (RAM) console and grant the required permissions to a RAM role. For more information, see the Preparations section of this topic.

When you configure the RAM role, set Account B as the trusted account and authorize the RAM role to access the cloud resources of Account A.

2. Use Account B that owns the destination instance to log on to the DTS console and configure the data synchronization task. For more information, see the Procedure section of this topic.

DTS can read information about the source ApsaraDB for Redis instance across Alibaba Cloud accounts.

Supported source and destination databases

The following table describes the supported databases when you use DTS to perform one-way synchronization between ApsaraDB for Redis instances across Alibaba Cloud accounts.

Source database

Destination database

  • ApsaraDB for Redis instance

  • Self-managed database that is hosted on Elastic Compute Service (ECS)

  • Self-managed database connected over Express Connect, VPN Gateway, or Smart Access Gateway

  • Self-managed database that is connected over Cloud Enterprise Network (CEN)

  • ApsaraDB for Redis instance

  • Self-managed database that is hosted on ECS

  • Self-managed database connected over Express Connect, VPN Gateway, or Smart Access Gateway

  • Self-managed database that is connected over CEN

Limits

Category

Description

Limits on the source database

  • The collections to be synchronized must have PRIMARY KEY or UNIQUE constraints, and all fields must be unique. Otherwise, the destination database may contain duplicate data records.

  • To ensure the synchronization quality, Data Transmission Service (DTS) adds a key prefixed with DTS_REDIS_TIMESTAMP_HEARTBEAT to the source database. This key is used to record the time when data is synchronized to the destination database. If the source database is deployed in a cluster architecture, DTS adds this key on each shard. The key is filtered out during data synchronization. After the data synchronization task is complete, the key expires.

  • If the source database is a read-only database or the source database account that is used to run the data synchronization task does not have the permissions to run the SETEX command, the reported latency may be inaccurate.

  • To ensure the stability of data synchronization, we recommend that you increase the value of the repl-backlog-size parameter in the redis.conf file.

  • You must enable the append-only file (AOF) logging feature for the source database.

  • If an expiration policy is enabled for specific keys in the source database, these keys may not be deleted at the earliest opportunity after they expire. Therefore, the number of keys in the destination database may be less than that in the source database. You can run the INFO command to view the number of keys in the destination database.

  • Limits on synchronizing data from a standalone Redis instance to a Redis cluster: Each command can be run only on a single slot in a Redis cluster. If you perform operations on multiple keys in the source database and the keys belong to different slots, the following error occurs:

    CROSSSLOT Keys in request don't hash to the same slot

    We recommend that you perform operations on only one key during data synchronization. This prevents the data synchronization task from being interrupted.

  • A Tair cloud-native ESSD-based instance cannot be configured as the source database.

  • A Tair cloud-native enhanced SSD (ESSD)-based instance cannot be configured as the source database.

  • If the source database is a Tair cloud-native persistent memory-optimized instance, you must set the appendonly parameter to yes for the instance.

Other limits

  • The timeout period for data replication between the master and replica nodes in the source Redis instance is specified by the repl-timeout parameter. If the source instance is a self-managed Redis database, we recommend that you run the config set repl-timeout 600 command to set this timeout period to 600 seconds. If the source database stores a large amount of data, you can increase the value of the repl-timeout parameter based on your business requirements.

  • During data synchronization, if the number of shards in the source Redis database is increased or decreased, or if you change the database specifications, such as scaling up the memory capacity, you must reconfigure the data synchronization task. To ensure data consistency, we recommend that you clear the data that has been synchronized to the destination Redis database before you reconfigure the data synchronization task.

  • During data synchronization, if the endpoint of the source Redis database is changed, you must reconfigure the data synchronization task.

  • To ensure compatibility, the version of the destination database must be the same as or later than that of the source database. If the version of the destination database is earlier than that of the source database, database compatibility issues may occur.

  • During initial full data synchronization, DTS uses the read and write resources of the source and destination databases. This may increase the loads on the database servers. Before you synchronize data, evaluate the impact of data synchronization on the performance of the source and destination databases. We recommend that you synchronize data during off-peak hours.

  • During data synchronization, we recommend that you use only DTS to write data to the destination database. This prevents data inconsistency between the source and destination databases.

  • If the destination instance is deployed in a cluster architecture and the amount of memory used by a shard in the destination instance reaches the upper limit, or if the available storage space of the destination instance is insufficient, the data synchronization task fails due to out of memory (OOM).
  • By default, the maxmemory-policy parameter that specifies how data is evicted is set to volatile-lru for ApsaraDB for Redis instances. If the destination instance has insufficient memory, data inconsistency may occur between the source and destination instances due to data eviction. In this case, the data synchronization task does not stop running.

    To prevent data inconsistency, we recommend that you set maxmemory-policy to noeviction for the destination instance. This way, the data synchronization task fails if the destination instance has insufficient memory, but data loss can be prevented for the destination instance.

    Note For more information about data eviction policies, see How does ApsaraDB for Redis evict data by default?
  • If the transparent data encryption (TDE) feature is enabled for the source or destination instance, you cannot use DTS to synchronize data from the source database to the destination database.

Billing

Synchronization typeTask configuration fee
Schema synchronization and full data synchronizationFree of charge.
Incremental data synchronizationCharged. For more information, see Billing overview.

Commands that can be synchronized

Edition

Command

ApsaraDB for Redis Community Edition instance

  • APPEND

  • BITOP, BLPOP, BRPOP, and BRPOPLPUSH

  • DECR, DECRBY, and DEL

  • EVAL, EVALSHA, EXEC, EXPIRE, and EXPIREAT

  • GEOADD and GETSET

  • HDEL, HINCRBY, HINCRBYFLOAT, HMSET, HSET, and HSETNX

  • INCR, INCRBY, and INCRBYFLOAT

  • LINSERT, LPOP, LPUSH, LPUSHX, LREM, LSET, and LTRIM

  • MOVE, MSET, MSETNX, and MULTI

  • PERSIST, PEXPIRE, PEXPIREAT, PFADD, PFMERGE, and PSETEX

  • RENAME, RENAMENX, RESTORE, RPOP, RPOPLPUSH, RPUSH, and RPUSHX

  • SADD, SDIFFSTORE, SELECT, SET, SETBIT, SETEX, SETNX, SETRANGE, SINTERSTORE, SMOVE, SPOP, SREM, and SUNIONSTORE

  • ZADD, ZINCRBY, ZINTERSTORE, ZREM, ZREMRANGEBYLEX, ZUNIONSTORE, ZREMRANGEBYRANK, and ZREMRANGEBYSCORE

  • SWAPDB and UNLINK (These two commands can be synchronized only if the engine version of the source instance is Redis 4.0.)

ApsaraDB for Redis Enhanced Edition (Tair) instance

  • APPEND

  • BITOP, BLPOP, BRPOP, and BRPOPLPUSH

  • DECR, DECRBY, and DEL

  • EVAL, EVALSHA, EXEC, EXPIRE, and EXPIREAT

  • GEOADD and GETSET

  • HDEL, HINCRBY, HINCRBYFLOAT, HMSET, HSET, and HSETNX

  • INCR, INCRBY, and INCRBYFLOAT

  • LINSERT, LPOP, LPUSH, LPUSHX, LREM, LSET, and LTRIM

  • MOVE, MSET, MSETNX, and MULTI

  • PERSIST, PEXPIRE, PEXPIREAT, PFADD, PFMERGE, and PSETEX

  • RENAME, RENAMENX, RPOP, RPOPLPUSH, RPUSH, and RPUSHX

  • SADD, SDIFFSTORE, SELECT, SET, SETBIT, SETEX, SETNX, SETRANGE, SINTERSTORE, SMOVE, SPOP, SREM, and SUNIONSTORE

  • UNLINK, ZADD, ZINCRBY, ZINTERSTORE, ZREM, ZREMRANGEBYLEX, ZUNIONSTORE, ZREMRANGEBYRANK, and ZREMRANGEBYSCORE

Note
  • PUBLISH operations cannot be synchronized.
  • If you run the EVAL or EVALSHA command to call Lua scripts, DTS cannot identify whether these Lua scripts are executed on the destination instance. This is because the destination instance does not explicitly return the execution results of Lua scripts during incremental data synchronization.
  • When DTS runs the SYNC or PSYNC command to transfer data of the LIST type, DTS does not clear the existing data in the destination instance. As a result, the destination instance may contain duplicate data records.

Preparations

  1. Required. Obtain the IDs of the Alibaba Cloud accounts that own the source and destination instances.

    Note

    Skip the step if you have obtained the IDs of the Alibaba Cloud accounts that own the source and destination instances.

    1. Log on to the Account Management console by using the Alibaba Cloud account that owns the source or destination instance.

    2. Optional. In the left-side navigation pane, click Basic Information.

    3. View and record the value of the Account ID parameter.

  2. Create a RAM role.

    1. Log on to the RAM console by using the Alibaba Cloud account that owns the source instance.

    2. In the left-side navigation pane, choose Identities > Roles.

    3. On the Roles page, click Create Role.

    4. In the Create Role panel, select Alibaba Cloud Account for the Select Trusted Entity parameter and click Next.创建角色

    5. In the Configure Role step, configure parameters for the RAM role.信任账号

      Parameter

      Description

      RAM Role Name

      The name of the RAM role. In this example, ram-for-dts is used.

      Note

      The name must be 1 to 64 characters in length and can contain letters, digits, and hyphens (-).

      Note

      Optional. The description of the RAM role.

      Select Trusted Alibaba Cloud Account

      Select Other Alibaba Cloud Account and enter the ID of the Alibaba Cloud account that owns the destination instance.

    6. Click OK.

  3. Grant permissions to the created RAM role.

    1. Click Input and Attach.创建角色

    2. In the Add Permissions panel, select System Policy for Type.添加权限

    3. In the Policy Name field, enter AliyunDTSRolePolicy.

    4. Click OK.

    5. After you grant the permissions, click Close.

  4. Modify the trust policy.

    1. On the RAM Roles page, find the RAM role that you created, and click the role name to view details.角色

    2. On the Basic Information page of the RAM role, click the Trust Policy Management tab.信任策略管理

    3. On the page that appears, click Edit Trust Policy.

    4. Copy the following code to the code editor:

      {
          "Statement": [
              {
                  "Action": "sts:AssumeRole",
                  "Effect": "Allow",
                  "Principal": {
                      "RAM": [
                          "acs:ram::<ID of the Alibaba Cloud account>:root"
                      ],
                      "Service": [
                          "<ID of the Alibaba Cloud account>@dts.aliyuncs.com"
                      ]
                  }
              }
          ],
          "Version": "1"
      }
    5. In the preceding code, replace ID of the Alibaba Cloud account with the Alibaba Cloud account ID that is used to create the DTS task.

    6. Click OK.

Procedure

  1. Use the Alibaba Cloud account that owns the destination ApsaraDB for Redis instance to log on to the new DTS console and go to the Data Synchronization page.

    1. Log on to the Data Management (DMS) console.

    2. In the top navigation bar, click DTS.

    3. In the top navigation bar, choose DTS > Data Synchronization.

  2. From the drop-down list to the right of Data Synchronization Tasks, select the region in which the data synchronization instance resides.
    Note If you use the new DTS console, you must select the region in which the data synchronization instance resides in the top navigation bar.
  3. Click Create Task. On the page that appears, configure the source and destination databases.

    Warning

    After you configure the source and destination databases, we recommend that you read the limits that are displayed in the upper part of the page. Otherwise, the task may fail or data inconsistency may occur.

    Section

    Parameter

    Description

    N/A

    Task Name

    The name of the task. DTS automatically assigns a name to the task. We recommend that you specify a descriptive name that makes it easy to identify the task. You do not need to specify a unique task name.

    Source Database

    Select an existing DMS database instance

    The database instance that you want to use. You can determine whether to select an existing instance based on your business requirements.

    • If you select an existing instance, DTS automatically populates the parameters for the instance.

    • If you do not select an existing instance, you must configure parameters for the source database.

    Database Type

    The type of the source database. Select ApsaraDB for Redis Enhanced Edition (Tair).

    Access Method

    The access method of the source database. Select Alibaba Cloud Instance.

    Instance Region

    The region in which the source ApsaraDB for Redis instance resides.

    Replicate Data Across Alibaba Cloud Accounts

    Specifies whether to synchronize data across Alibaba Cloud accounts. In this example, Yes is selected.

    Note

    The two accounts can be an Alibaba Cloud account on the China site (aliyun.com) and an Alibaba Cloud account on the International site (alibabacloud.com).

    Alibaba Cloud Account

    The ID of the Alibaba Cloud account that owns the source ApsaraDB for Redis instance.

    Note

    To obtain the ID of the Alibaba Cloud account, you can log on to the Account Management console by using this account. The account ID is displayed on the Basic Information page.

    获取云账号ID

    RAM Role Name

    The name of the RAM role that you created by following the instructions in the Preparations section of this topic.

    Instance ID

    The ID of the source ApsaraDB for Redis instance.

    Database Password

    The database password of the source ApsaraDB for Redis instance. The database account that corresponds to the password must have the read permissions. If you forget the password, you can reset the password. For more information, see Change or reset the password.

    • If you use the default account whose username is the same as the instance ID, you need to enter only the password.

    • If you use a custom account, specify the password in the <Custom account username>:<Password> format. Example: testaccount:Test1234.

    Note

    This parameter is optional and can be left empty if no database password is set for the source Redis database.

    Destination Database

    Select an existing DMS database instance

    The database instance that you want to use. You can determine whether to select an existing instance based on your business requirements.

    • If you select an existing instance, DTS automatically populates the parameters for the instance.

    • If you do not select an existing instance, you must configure parameters for the destination database.

    Database Type

    The type of the destination database. Select ApsaraDB for Redis Enhanced Edition (Tair).

    Access Method

    The access method of the destination database. Select Alibaba Cloud Instance.

    Instance Region

    The region in which the destination ApsaraDB for Redis instance resides.

    Instance ID

    The ID of the destination ApsaraDB for Redis instance.

    Database Password

    The database password of the destination ApsaraDB for Redis instance. The database account that corresponds to the password must have the read permissions. If you forget the password, you can reset the password. For more information, see Change or reset the password.

    • If you use the default account whose username is the same as the instance ID, you need to enter only the password.

    • If you use a custom account, specify the password in the <Custom account username>:<Password> format. Example: testaccount:Test1234.

  4. In the lower part of the page, click Test Connectivity and Proceed.

    If the source or destination database is an Alibaba Cloud database instance, such as an ApsaraDB RDS for MySQL or ApsaraDB for MongoDB instance, DTS automatically adds the CIDR blocks of DTS servers to the whitelist of the instance. If the source or destination database is a self-managed database hosted on an Elastic Compute Service (ECS) instance, DTS automatically adds the CIDR blocks of DTS servers to the security group rules of the ECS instance, and you must ensure that the ECS instance can access the database. If the source or destination database is a self-managed database that is deployed in a data center or provided by a third-party cloud service provider, you must manually add the CIDR blocks of DTS servers to the whitelist of the database to allow DTS to access the database. For more information, see Add the CIDR blocks of DTS servers to the security settings of on-premises databases.

    Warning

    If the CIDR blocks of DTS servers are automatically or manually added to the whitelist of the database or instance, or to the ECS security group rules, security risks may arise. Therefore, before you use DTS to synchronize data, you must understand and acknowledge the potential risks and take preventive measures, including but not limited to the following measures: enhancing the security of your username and password, limiting the ports that are exposed, authenticating API calls, regularly checking the whitelist or ECS security group rules and forbidding unauthorized CIDR blocks, or connecting the database to DTS by using Express Connect, VPN Gateway, or Smart Access Gateway.

  5. Configure the objects to be synchronized and advanced settings.

    Parameter

    Description

    Synchronization Type

    By default, Incremental Data Synchronization is selected. You must also select Full Data Synchronization. After the precheck, DTS synchronizes all the existing data of the selected objects from the source database to the destination database. The data is the basis for subsequent incremental synchronization.

    Note

    Full data synchronization is supported only for ApsaraDB for Redis Enhanced Edition (Tair) instances.

    Synchronization Topology

    The synchronization topology of the data synchronization task. Select One-way Synchronization.

    Processing Mode of Conflicting Tables

    • Precheck and Report Errors: checks whether the destination database contains tables that have the same names as tables in the source database. If the source and destination databases do not contain tables that have identical table names, the precheck is passed. Otherwise, an error is returned during the precheck and the data synchronization task cannot be started.

    • Ignore Errors and Proceed: skips the precheck for identical table names in the source and destination databases.

      Warning

      If you select Ignore Errors and Proceed, data inconsistency may occur and your business may be exposed to potential risks.

    Source Objects

    Select one or more objects from the Source Objects section and click the Rightwards arrow icon to add the objects to the Selected Objects section.

    Note

    You can select only databases as the objects to be synchronized. You cannot select keys as the objects to be synchronized.

    Selected Objects

    In the Selected Objects section, right-click an object. In the dialog box that appears, select the commands that you want to synchronize. For more information, see the Commands that can be synchronized section of this topic.

    Note

    In this scenario, you cannot rename the objects.

  6. Click Next: Advanced Settings to configure advanced settings.

    • Data Verification Settings

      For more information about how to configure the data verification feature, see Enable data verification.

    • Advanced Settings

      Parameter

      Description

      Set Alerts

      Specifies whether to configure alerting for the data synchronization task. If the task fails or the synchronization latency exceeds the specified threshold, alert contacts will receive notifications. Valid values:

      Retry Time for Failed Connections

      The retry time range for failed connections. If the source or destination database fails to be connected after the data synchronization task is started, DTS immediately retries a connection within the time range. Valid values: 10 to 1440. Unit: minutes. Default value: 720. We recommend that you set the parameter to a value greater than 30. If DTS reconnects to the source and destination databases within the specified time range, DTS resumes the data synchronization task. Otherwise, the data synchronization task fails.

      Note
      • If you set different retry time ranges for multiple DTS tasks that have the same source or destination database, the shortest retry time range that is set takes precedence.

      • When DTS retries a connection, you are charged for the DTS instance. We recommend that you specify the retry time range based on your business requirements. You can also release the DTS instance at your earliest opportunity after the source and destination instances are released.

      The wait time before a retry when other issues occur in the source and destination databases.

      The retry time range for other issues. For example, if the DDL or DML operations fail to be performed after the data synchronization task is started, DTS immediately retries the operations within the time range. Valid values: 1 to 1440. Unit: minutes. Default value: 10. We recommend that you set the parameter to a value greater than 10. If the failed operations are successfully performed within the specified time range, DTS resumes the data synchronization task. Otherwise, the data synchronization task fails.

      Important

      The value of the The wait time before a retry when other issues occur in the source and destination databases parameter must be smaller than the value of the Retry Time for Failed Connection parameter.

      Enable Throttling for Full Data Migration

      During full data migration, DTS uses the read and write resources of the source and destination databases. This may increase the loads of the database servers. You can configure the Queries per second (QPS) to the source database, RPS of Full Data Migration, and BPS of Full Data Migration parameters for full data synchronization tasks to reduce the pressure on the destination database.

      Note

      This parameter can be configured only if Full Data Synchronization is selected as Synchronization Types.

      Enable Throttling for Incremental Data Synchronization

      You can configure the RPS of Incremental Data Migration and BPS of Incremental Data Migration parameters for incremental data synchronization tasks to reduce the pressure on the destination database.

      Environment Tag

      The environment tag that is used to identify the DTS instance. You can select an environment tag based on your business requirements. In this example, no environment tag is selected.

      Extend Expiration Time of Destination Database Key

      The extended time period for keys synchronized from the source database to the destination database to remain valid. Unit: seconds. If specific commands are used, such as the following commands, we recommend that you set the parameter to 600 to ensure data consistency.

      EXPIRE key seconds
      PEXPIRE key milliseconds
      EXPIREAT key timestamp
      PEXPIREAT key timestampMs

      Configure ETL

      Specifies whether to configure the extract, transform, and load (ETL) feature. For more information, see What is ETL?. Valid values:
  7. Click Next: Save Task Settings and Precheck in the lower part of the page.

    You can move the pointer over Next: Save Task Settings and Precheck and click Preview OpenAPI parameters to view the parameter settings of the API operation that is called to configure the instance.

    Note
    • Before you can start the data synchronization task, DTS performs a precheck. You can start the data synchronization task only after the task passes the precheck.

    • If the task fails to pass the precheck, click View Details next to each failed item. After you troubleshoot the issues based on the causes, run a precheck again.

    • If an alert is triggered for an item during the precheck:

      • If an alert item cannot be ignored, click View Details next to the failed item and troubleshoot the issues. Then, run a precheck again.

      • If an alert item can be ignored, click Confirm Alert Details. In the View Details dialog box, click Ignore. In the message that appears, click OK. Then, click Precheck Again to run a precheck again. If you ignore the alert item, data inconsistency may occur, and your business may be exposed to potential risks.

  8. Wait until the success rate becomes 100%. Then, click Next: Purchase Instance.

  9. On the Purchase Instance page, configure the Billing Method and Instance Class parameters for the data synchronization instance. The following table describes the parameters.

    Section

    Parameter

    Description

    New Instance Class

    Billing Method

    • Subscription: You pay for the instance when you create an instance. The subscription billing method is more cost-effective than the pay-as-you-go billing method for long-term use.

    • Pay-as-you-go: A pay-as-you-go instance is charged on an hourly basis. The pay-as-you-go billing method is suitable for short-term use. If you no longer require a pay-as-you-go instance, you can release the pay-as-you-go instance to reduce costs.

    Resource Group

    The resource group on which the instance is run. Default value: default resource group. For more information, see What is Resource Management?.

    Instance Class

    DTS provides various synchronization specifications that provide different performance. The synchronization speed varies based on the synchronization specifications that you select. You can select a synchronization specification based on your business scenario. For more information, see Specifications of data synchronization instances.

    Subscription Duration

    If you select the subscription billing method, set the subscription duration and the number of instances that you want to create. The subscription duration can be one to nine months, one year, two years, three years, or five years.

    Note

    This parameter is available only if you select the Subscription billing method.

  10. Read and select the check box to agree to the Data Transmission Service (Pay-as-you-go) Service Terms.

  11. Click Buy and Start to start the data synchronization task. You can view the progress of the task in the task list.