Synchronize MongoDB (without shard keys) to MongoDB (sharded cluster architecture)

Data Transmission Service (DTS) supports synchronizing data from a source MongoDB instance without shard key fields to a MongoDB sharded cluster architecture and specifying default values for shard keys. This topic uses ApsaraDB for MongoDB (ReplicaSet architecture) as the source and ApsaraDB for MongoDB (sharded cluster architecture) as the destination to describe the synchronization steps.

Prerequisites

The destination ApsaraDB for MongoDB (sharded cluster architecture) has been created. For more information, see Create a sharded cluster instance.
Note
- If the source is a sharded cluster architecture ApsaraDB for MongoDB, you need to apply for connection addresses for all Shard nodes, and ensure that the accounts and passwords of each Shard are consistent. For application methods, see Apply for Shard or ConfigServer node connection addresses.
- For supported versions, see Synchronization solution overview.
The storage space of the destination ApsaraDB for MongoDB is larger than that of the source ApsaraDB for MongoDB. It is recommended that the storage space of the destination is 10% larger than that of the source.
According to business needs, create the databases and collections that need to be sharded in the destination ApsaraDB for MongoDB, configure data sharding, enable the Balancer, and perform pre-sharding. For more information, see Set data sharding to fully utilize Shard performance and How to handle uneven data distribution in MongoDB sharded cluster architecture.
Note
Configuring data sharding can prevent data from being synchronized to the same Shard, which would otherwise hinder cluster performance. Enabling the Balancer and performing pre-sharding can prevent data skew issues.

Notes

Type	Description

Type	Description
Source database limitations	Bandwidth requirements: The server where the source database resides must have sufficient outbound bandwidth. Otherwise, the data synchronization rate will be affected. The collections to be synchronized must have primary keys or UNIQUE constraints, and all fields must be unique. Otherwise, duplicate data may appear in the destination database. If the granularity of the synchronization object is a collection and needs editing (such as collection name mapping), a single synchronization task supports synchronizing up to 1,000 collections. If the number exceeds the limit, a request error will be displayed after the task is submitted. In this case, it is recommended to split the collections to be synchronized, configure multiple tasks in batches, or configure a task to synchronize the entire database. The size of a single data entry to be synchronized from the source database cannot exceed 16 MB. Otherwise, the task fails. If the source MongoDB is a sharded cluster instance, the number of source Mongos nodes cannot exceed 10. The source database cannot be an Azure Cosmos DB for MongoDB cluster or an Amazon DocumentDB elastic cluster. The oplog feature must be enabled for the source database and must retain log data for at least seven days. Alternatively, change streams must be enabled to ensure that DTS can subscribe to data changes in the source database within the last seven days. Otherwise, DTS may fail to obtain data changes in the source database and data synchronization fails. In some circumstances, data inconsistency or data loss may occur. Issues that arise in such circumstances are not covered by the service level agreement (SLA) of DTS. Important We recommend that you use the oplog to record data changes in the source database. Only MongoDB 4.0 and later allow you to use change streams to obtain data changes in the source database. Two-way synchronization is not supported when you use change streams to obtain data changes in the source database. If the source database is a non-elastic Amazon DocumentDB cluster, you must enable change streams and set the Migration Method parameter to ChangeStream and the Architecture parameter to Sharded Cluster. Source database operation limitations: During schema synchronization and full data synchronization, do not change the schemas of the databases or collections, including the update of array type. Otherwise, the data synchronization task fails or data inconsistency may occur between the source and destination databases. If only full data synchronization is performed, do not write new data to the source instance. Otherwise, the data between the source and destination databases will be inconsistent. To maintain real-time data consistency, it is recommended to select schema synchronization, full data synchronization, and incremental data synchronization. You cannot synchronize collections that contain time to live (TTL) indexes. If the source database contains TTL indexes, data inconsistency may occur between the source and destination databases after the synchronization. Ensure that there are no orphaned documents in the MongoDB instance with a sharded cluster architecture. Otherwise, data inconsistency or even task failure may occur. For more information, see Orphaned documents and How to clean orphaned documents in MongoDB (sharded cluster architecture). If the source database is a MongoDB with a sharded cluster architecture, and the Balancer of the source database has balancing data behavior, it may cause instance latency.
Other limitations	During synchronization, newly added collections on the source side do not support setting default values for shard keys. When the source is a non-sharded cluster and the destination is Alibaba Cloud MongoDB (sharded cluster architecture), it will enter the Configure Database and Table Fields stage. When the version of the destination MongoDB (sharded cluster architecture) is lower than 4.4, the default value of the ShardKey set in the Configure Database and Table Fields stage will take effect. DTS fills the original data with the default value you set and writes it to the destination. If the destination MongoDB (sharded cluster architecture) is version 4.4 or above, the default value set in the Configure Database and Table Fields stage will not take effect. DTS writes the original data to the destination by default. It is recommended that the MongoDB database versions of the source and destination databases remain consistent, or synchronize from a lower version to a higher version to ensure compatibility. If synchronizing from a higher version to a lower version, there may be database compatibility issues. Synchronization of data in the admin and local databases is not supported. If a collection of the destination database has a unique index or the `capped` attribute of a collection of the destination database is `true`, the collection supports only single-thread data writing and does not support concurrent replay during incremental data synchronization. This may increase synchronization latency. Transaction information is not retained. Transactions in the source database are converted to single records when synchronized to the destination database. Before performing data synchronization, evaluate the performance of the source and destination databases. It is also recommended to perform data synchronization during off-peak business hours. Otherwise, during full data synchronization, DTS occupies certain read and write resources of the source and destination databases, which may increase the load on the databases. Because full data synchronization performs INSERT operations concurrently, it causes fragmentation in the collections of the destination database. Therefore, after full synchronization is complete, the collection storage space of the destination database will be larger than that of the source instance. During DTS synchronization, do not write data to the destination database from sources other than DTS. Otherwise, data inconsistency between the source and destination databases will occur. DTS will attempt to recover synchronization tasks that failed within seven days. Therefore, before switching business to the destination instance, be sure to end or release the task, or revoke the write permissions of the DTS access account to the destination instance. This prevents the task from being automatically recovered and overwriting the destination data with the source data. Because DTS writes data concurrently, the storage space occupied by the destination is 5% to 10% larger than that of the source. The count number of the destination MongoDB needs to be queried using the `db.$table_name.aggregate([{ $count:"myCount"}])` syntax. Ensure that the destination MongoDB does not have the same primary key as the source (the default is _id). Otherwise, data loss will occur. If the destination has the same primary key as the source, clear the relevant data in the destination without affecting business (delete the document in the destination with the same _id as the source). If a DTS task fails to run, DTS technical support will try to restore the task within 8 hours. During the restoration, the task may be restarted, and the parameters of the task may be modified. Note Only the parameters of the task may be modified. The parameters of databases are not modified. The parameters that may be modified include but are not limited to the parameters in the "Modify instance parameters" section of the Modify the parameters of a DTS instance topic.
Special cases	When the source database is a self-managed MongoDB: During synchronization, if the source database undergoes a primary-secondary switch, the synchronization task will fail. Because the delay time of DTS is calculated based on the comparison between the timestamp of the last data synchronized to the destination database and the current timestamp, if the source database has not performed update operations for a long time, the delay information may be inaccurate. If the delay time displayed by the task is too large, you can perform an update operation on the source database to update the delay information. Note If the synchronization object is selected as the entire database, you can also create a heartbeat that periodically updates or writes data every second.

Billing

Synchronization type	Task configuration fee

Synchronization type	Task configuration fee
Schema synchronization and full data synchronization	Free of charge.
Incremental data synchronization	Charged. For more information, see Billing overview.

Synchronization types

Synchronization type	Description

Synchronization type	Description
Schema synchronization	DTS synchronizes the schemas of the selected objects from the source ApsaraDB for MongoDB instance to the destination ApsaraDB for MongoDB instance.
Full data synchronization	DTS synchronizes the historical data of the selected objects from the source ApsaraDB for MongoDB instance to the destination ApsaraDB for MongoDB instance. Note DTS supports full data synchronization for the following types of objects: databases and collections.
Incremental data synchronization	DTS synchronizes incremental data from the source ApsaraDB for MongoDB instance to the destination ApsaraDB for MongoDB instance. Use oplog Use change streams A DTS task does not synchronize incremental data from databases that are created after the task starts to run. DTS synchronizes incremental data generated by the following operations: CREATE COLLECTION and CREATE INDEX DROP DATABASE, DROP COLLECTION, and DROP INDEX RENAME COLLECTION The operations that are performed to insert, update, and delete documents in a collection. Note When a DTS task synchronizes incremental data of a file, Only `$set` command can be synchronously run. DTS synchronizes incremental data generated by the following operations: DROP DATABASE and DROP COLLECTION RENAME COLLECTION The operations that are performed to insert, update, and delete documents in a collection. Note When a DTS task synchronizes incremental data of a file, Only `$set` command can be synchronously run.

Permissions required for database accounts

Database	Required permissions	Creation and authorization method

Database	Required permissions	Creation and authorization method
Source ApsaraDB for MongoDB	Read permissions for the databases to be synchronized, config database, admin database, and local database.	Manage MongoDB database users using DMS
Destination ApsaraDB for MongoDB	dbAdminAnyDatabase permission, readWrite permission for the destination database, read permission for the local database, and read permission for the config database.	Manage MongoDB database users using DMS

Procedure

Use one of the following methods to go to the Data Synchronization page and select the region in which the data synchronization instance resides.
DTS console
DMS console
1. Log on to the DTS console.
2. In the left-side navigation pane, click Data Synchronization.
3. In the upper-left corner of the page, select the region in which the data synchronization instance resides.
Note
The actual operations may vary based on the mode and layout of the DMS console. For more information, see Simple mode and Customize the layout and style of the DMS console.
1. Log on to the DMS console.
2. In the top navigation bar, move the pointer over Data + AI and choose DTS (DTS) > Data Synchronization.
3. From the drop-down list to the right of Data Synchronization Tasks, select the region in which the data synchronization instance resides.
Click Create Task to go to the task configuration page.
Optional. Click New Configuration Page in the upper-right corner of the page.
Note
- Skip this step if the Back to Previous Version button is displayed in the upper-right corner of the page.
- Specific parameters in the new and previous versions of the configuration page may be different. We recommend that you use the new version of the configuration page.

Configure the source and destination databases. The following table describes the parameters.

Category	Configuration	Description

Category	Configuration	Description
None	Task Name	The name of the DTS task. DTS automatically generates a task name. 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 Existing Connection	The database that you want to use. You can choose whether to use an existing database based on your business requirements. If you select an existing database, DTS automatically populates the parameters for the database. If you do not select an existing database, you must configure the following database information. Note In the DTS console, register a database with DTS on the Database Connections page or the new configuration page. For more information, see Manage database connections. In the DMS console, you can select an existing database from the Select a DMS database instance. drop-down list. You can also click Add DMS Database Instance or go back to the homepage of the DMS console to register a database with DMS. For more information, see Register an Alibaba Cloud database instance and Register a database hosted on a third-party cloud service or a self-managed database.
	Database Type	Select MongoDB.
	Access Method	Select Alibaba Cloud Instance.
	Instance Region	Select the region where the source ApsaraDB for MongoDB instance resides.
	Replicate Data Across Alibaba Cloud Accounts	This example is for synchronization between the same Alibaba Cloud account. Select No.
	Architecture	This example selects Replica Set. Replica Set: Achieves high availability and read/write splitting by deploying multiple nodes. For more information, see ReplicaSet architecture. Sharded Cluster: Provides three components: Mongos, Shard, and ConfigServer. You can freely choose the number and configuration of Mongos and Shard. For more information, see Sharded cluster architecture.
	Migration Method	The method used to synchronize incremental data from the source database. Select a method based on your business requirements. Valid values: Oplog (recommended): This option is available if the oplog feature is enabled for the source database. Note By default, the oplog feature is enabled for both self-managed MongoDB databases and ApsaraDB for MongoDB instances. This feature allows you to synchronize incremental data at a low latency because of a fast log pulling speed. Therefore, we recommend that you select Oplog for the Migration Method parameter. ChangeStream: This option is available if change streams are enabled for the source database. For more information, see Change Streams. Note If the source database is an inelastic Amazon DocumentDB cluster, you can set the Migration Method parameter only to ChangeStream. If you select Sharded Cluster for the Architecture parameter, you do not need to configure the Shard account and Shard password parameters.
	Instance ID	Select the instance ID of the source ApsaraDB for MongoDB.
	Authentication Database	Enter the name of the database to which the database account of the source ApsaraDB for MongoDB instance belongs. If it has not been modified, the default is admin.
	Database Account	Enter the database account of the source ApsaraDB for MongoDB instance. For permission requirements, see Permissions required for database accounts.
	Database Password	The password that is used to access the database.
	Encryption	Specifies whether to encrypt the connection to the source database. You can select Non-encrypted, SSL-encrypted, or Mongo Atlas SSL based on your business requirements. The options available for the Encryption parameter are determined by the values selected for the Access Method and Architecture parameters. The options displayed in the DTS console prevail. Note If the Architecture parameter is set to Sharded Cluster, and the Migration Method parameter is set to Oplog for the ApsaraDB for MongoDB database, the Encryption parameter SSL-encrypted is unavailable. If the source database is a self-managed MongoDB database that uses the Replica Set architecture, the Access Method parameter is not set to Alibaba Cloud Instance, and the Encryption parameter is set to SSL-encrypted, you can upload a certification authority (CA) certificate to verify the connection to the source database.
Destination Database	Select Existing Connection	The database that you want to use. You can choose whether to use an existing database based on your business requirements. If you select an existing database, DTS automatically populates the parameters for the database. If you do not select an existing database, you must configure the following database information. Note In the DTS console, register a database with DTS on the Database Connections page or the new configuration page. For more information, see Manage database connections. In the DMS console, you can select an existing database from the Select a DMS database instance. drop-down list. You can also click Add DMS Database Instance or go back to the homepage of the DMS console to register a database with DMS. For more information, see Register an Alibaba Cloud database instance and Register a database hosted on a third-party cloud service or a self-managed database.
	Database Type	Select MongoDB.
	Access Method	Select Alibaba Cloud Instance.
	Instance Region	Select the region where the destination ApsaraDB for MongoDB instance resides.
	Replicate Data Across Alibaba Cloud Accounts	In this example, a database of the current Alibaba Cloud account is used. Select No.
	Architecture	This example requires selecting Sharded Cluster.
	Instance ID	Select the instance ID of the destination ApsaraDB for MongoDB.
	Authentication Database	Enter the name of the database to which the database account of the destination ApsaraDB for MongoDB instance belongs. If it has not been modified, the default is admin.
	Database Account	Enter the database account of the destination ApsaraDB for MongoDB. For permission requirements, see Permissions required for database accounts.
	Database Password	The password that is used to access the database.
	Encryption	Specifies whether to encrypt the connection to the destination database. You can select Non-encrypted, SSL-encrypted, or Mongo Atlas SSL based on your business requirements. The options available for the Encryption parameter are determined by the values selected for the Access Method and Architecture parameters. The options displayed in the DTS console prevail. Note If the destination database is an ApsaraDB for MongoDB instance and the Architecture parameter is set to Sharded Cluster, the Encryption parameter SSL-encrypted is unavailable. If the destination database is a self-managed MongoDB database that uses the Replica Set architecture, the Access Method parameter is not set to Alibaba Cloud Instance, and the Encryption parameter is set to SSL-encrypted, you can upload a CA certificate to verify the connection to the destination database.

Click Test Connectivity and Proceed in the lower part of the page.
Note
- Make sure that the CIDR blocks of DTS servers can be automatically or manually added to the security settings of the source and destination databases to allow access from DTS servers. For more information, see Add the CIDR blocks of DTS servers.
- If the source or destination database is a self-managed database and its Access Method is not set to Alibaba Cloud Instance, click Test Connectivity in the CIDR Blocks of DTS Servers dialog box.

Configure the objects to be synchronized.

In the Configure Objects step, configure the objects that you want to synchronize.

Configuration	Description

Configuration	Description
Synchronization Types	The synchronization types. By default, Incremental Data Synchronization is selected. You must also select Schema Synchronization and Full Data Synchronization. After the precheck is complete, DTS synchronizes the historical data of the selected objects from the source database to the destination cluster. The historical data is the basis for subsequent incremental synchronization.
Processing Mode of Conflicting Tables	Precheck and Report Errors: checks whether the destination database contains collections that have the same names as the collections in the source database. If the source and destination databases do not contain collections that have identical collection names, the precheck is passed. Otherwise, an error is returned during the precheck, and the data synchronization task cannot be started. Note If the source and destination databases have collections with identical names and the collections in the destination database cannot be deleted or renamed, you can use the object name mapping feature to rename the collections that are synchronized to the destination database. For more information, see Rename an object to be synchronized. Ignore Errors and Proceed: skips the precheck for identical collection 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. If a data record in the destination database has the same primary key value or unique key value as a data record in the source database, DTS does not synchronize the data record to the destination database. The existing data record in the destination database is retained. Data may fail to be initialized, only specific columns are synchronized, or the data synchronization task fails.
Synchronization Topology	Select One-way Synchronization.
Capitalization of Object Names in Destination Instance	The capitalization of database names, table names, and column names in the destination instance. By default, DTS default policy is selected. You can select other options to ensure that the capitalization of object names is consistent with that in the source or destination database. For more information, see Specify the capitalization of object names in the destination instance.
Source Objects	Select one or more objects from the Source Objects section and click the icon to add the objects to the Selected Objects section. Note The granularity of selecting synchronization objects is database or collection.
Selected Objects	To specify the database name in the destination MongoDB (sharded cluster architecture) for receiving data: Right-click the desired database under Selected Objects, and within the Edit Schema dialog box that appears, update the Schema Name to match the destination MongoDB database name (sharded cluster architecture) that will receive the data. For more information, see Single mapping of database table columns. To specify the collection name in the destination MongoDB (sharded cluster architecture) for receiving data: Right-click the collection under Selected Objects, and in the pop-up Edit Table dialog box, rename the Table Name to match the collection name in the destination MongoDB, which utilizes a sharded cluster architecture, to facilitate data reception. Important Only when the granularity of the synchronization object is a collection can you specify the collection for receiving data. Note If you need to establish filter conditions for data (note that filter conditions are supported during the full synchronization phase but not during the incremental synchronization phase), right-click the table you want to sync in Selected Objects, and define the filter conditions in the dialog box that appears. For instructions on how to configure these conditions, see Set filter conditions. If you use the object name mapping feature (specifying the database or collection for receiving data), it may cause synchronization failures for other objects that depend on this object.

Click Next: Advanced Settings to configure advanced settings.

Configuration	Description

Configuration	Description
Dedicated Cluster for Task Scheduling	By default, DTS schedules the task to the shared cluster if you do not specify a dedicated cluster. If you want to improve the stability of data synchronization tasks, purchase a dedicated cluster. For more information, see What is a DTS dedicated cluster.
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 this 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 specify different retry time ranges for multiple data synchronization tasks that have the same source or destination database, the shortest retry time range 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.
Retry Time for Other Issues	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 this 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 Retry Time for Other Issues parameter must be smaller than the value of the Retry Time for Failed Connections parameter.
Enable Throttling for Full Data Migration	During full data synchronization, DTS uses the read and write resources of the source and destination databases. This may increase the load on the database servers. You can configure the Queries per second (QPS) to the source database, RPS of Full Data Migration, and Data migration speed for full migration (MB/s) parameters for full data synchronization tasks to reduce the load on the destination database server. Note This parameter is displayed only if Full Data Synchronization is selected for the Synchronization Types parameter.
Only one data type for primary key _id in a single table	Whether the data type for primary key `_id` in a collection of the data to be synchronized is unique. Valif value: Note This parameter is displayed only if Full Data Synchronization is selected for the Synchronization Types parameter. Yes: The data type is unique. During full data synchronization, DTS does not scan the data type for primary key `_id` of the data to be synchronized from the source database. No: The data type is not unique. During full data synchronization, DTS scans the data type for primary key `_id` of the data to be synchronized from the source database.
Enable Throttling for Incremental Data Synchronization	Specifies whether to enable throttling for incremental data synchronization. You can enable throttling for incremental data synchronization based on your business requirements. To configure throttling, you must configure the RPS of Incremental Data Synchronization and Data synchronization speed for incremental synchronization (MB/s) parameters. This reduces the load on the destination database server.
Environment Tag	You can select an environment tag to identify the instance based on your actual situation. This example does not require selection.
Configure ETL	Specifies whether to enable the extract, transform, and load (ETL) feature. For more information, see What is ETL? Valid values: Yes: configures the ETL feature. You can enter data processing statements in the code editor. For more information, see Configure ETL in a data migration or data synchronization task. No: does not configure the ETL feature.
Monitoring and Alerting	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: No: does not enable alerting. Yes: configures alerting. In this case, you must also configure the alert threshold and alert notification settings. For more information, see the "Configure monitoring and alerting when you create a DTS task" section of the Configure monitoring and alerting topic.

Click Next Step: Data Verification to configure data verification.
For more information about how to use the data verification feature, see Configure a data verification task.
Click Next: Configure Database and Table Fields to set the default value for the ShardKey.
1. Click Set Default Value in the corresponding row of the target collection.
  Note
  If the Number of Shard Keys is 0 for a Table Name(collection), this indicates that the target collection does not contain a shard key, and setting a default value is unnecessary.
2. Select the Shard key default value type.
  Note
  The current Shard key default value type supports only string and int data types.
3. Set the Default Value for the ShardKey.
  Important
  - The set ShardKey default value will only take effect when the version of the destination MongoDB (sharded cluster architecture) is lower than 4.4.
  - You must assign default values to all ShardKeys within the objects slated for synchronization. If not, an alert will be triggered during the Precheck phase, potentially causing the task to fail.

Save the task settings and run a precheck.
- To view the parameters to be specified when you call the relevant API operation to configure the DTS task, move the pointer over Next: Save Task Settings and Precheck and click Preview OpenAPI parameters.
- If you do not need to view or have viewed the parameters, click Next: Save Task Settings and Precheck in the lower part of the page.
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 data synchronization task fails the precheck, click View Details next to each failed item. After you analyze the causes based on the check results, troubleshoot the issues. Then, rerun the precheck.
- 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 issue. 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.

Purchase an instance.

Wait until the Success Rate becomes 100%. Then, click Next: Purchase Instance.

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

Section	Parameter	Description

Section	Parameter	Description
New Instance Class	Billing Method	Subscription: You pay for a subscription when you create a data synchronization 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 billed 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 data synchronization instance, you can release the instance to reduce costs.
	Resource Group Settings	The resource group to which the data synchronization instance belongs. Default value: default resource group. For more information, see What is Resource Management?
	Instance Class	DTS provides instance classes that vary in synchronization speed. You can select an instance class based on your business requirements. For more information, see Instance classes of data synchronization instances.
	Subscription Duration	If you select the subscription billing method, specify the subscription duration and the number of data synchronization 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.

Read and select Data Transmission Service (Pay-as-you-go) Service Terms.
Click Buy and Start. In the dialog box that appears, click OK.
You can view the progress of the task in the task list.

Prerequisites

Notes

Billing

Synchronization types

Permissions required for database accounts

Procedure

Sales Support

Technical Support

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