Replicate Multiple Azure Data Lake Storage Accounts via the CData Sync CLI

CData Sync for Azure Data Lake Storage is a stand-alone application that provides solutions for a variety of replication scenarios such as replicating sandbox and production instances into your database. Both Sync for Windows and Sync for Java include a command-line interface (CLI) that makes it easy to manage multiple Azure Data Lake Storage connections. In this article we show how to use the CLI to replicate multiple Azure Data Lake Storage accounts.

Configure Azure Data Lake Storage Connections

You can save connection and email notification settings in an XML configuration file. To replicate multiple Azure Data Lake Storage accounts, use multiple configuration files. Below is an example configuration to replicate Azure Data Lake Storage to SQLite:

Windows

<?xml version="1.0" encoding="UTF-8" ?>
<CDataSync>
 <DatabaseType>SQLite</DatabaseType>
 <DatabaseProvider>System.Data.SQLite</DatabaseProvider>
 <ConnectionString>Schema=ADLSGen2;Account=myAccount;FileSystem=myFileSystem;AccessKey=myAccessKey;InitiateOAuth=GETANDREFRESH;</ConnectionString>
 <ReplicateAll>False</ReplicateAll>
 <NotificationUserName></NotificationUserName>
 <DatabaseConnectionString>Data Source=C:\my.db</DatabaseConnectionString>
 <TaskSchedulerStartTime>09:51</TaskSchedulerStartTime>
 <TaskSchedulerInterval>Never</TaskSchedulerInterval>
</CDataSync>

Java

<?xml version="1.0" encoding="UTF-8" ?>
<CDataSync>
<DatabaseType>SQLite</DatabaseType>
 <DatabaseProvider>org.sqlite.JDBC</DatabaseProvider>
 <ConnectionString>Schema=ADLSGen2;Account=myAccount;FileSystem=myFileSystem;AccessKey=myAccessKey;InitiateOAuth=GETANDREFRESH;</ConnectionString>
 <ReplicateAll>False</ReplicateAll>
 <NotificationUserName></NotificationUserName>
 <DatabaseConnectionString>Data Source=C:\my.db</DatabaseConnectionString>
</CDataSync>

Authenticating to a Gen 1 DataLakeStore Account

Gen 1 uses OAuth 2.0 in Entra ID (formerly Azure AD) for authentication.

For this, an Active Directory web application is required. You can create one as follows:

1. Sign in to your Azure Account through the
2. Select "Entra ID" (formerly Azure AD).
3. Select "App registrations".
4. Select "New application registration".
5. Provide a name and URL for the application. Select Web app for the type of application you want to create.
6. Select "Required permissions" and change the required permissions for this app. At a minimum, "Azure Data Lake" and "Windows Azure Service Management API" are required.
7. Select "Key" and generate a new key. Add a description, a duration, and take note of the generated key. You won't be able to see it again.

To authenticate against a Gen 1 DataLakeStore account, the following properties are required:

• Schema: Set this to ADLSGen1.
• Account: Set this to the name of the account.
• OAuthClientId: Set this to the application Id of the app you created.
• OAuthClientSecret: Set this to the key generated for the app you created.
• TenantId: Set this to the tenant Id. See the property for more information on how to acquire this.
• Directory: Set this to the path which will be used to store the replicated file. If not specified, the root directory will be used.

Authenticating to a Gen 2 DataLakeStore Account

To authenticate against a Gen 2 DataLakeStore account, the following properties are required:

• Schema: Set this to ADLSGen2.
• Account: Set this to the name of the account.
• FileSystem: Set this to the file system which will be used for this account.
• AccessKey: Set this to the access key which will be used to authenticate the calls to the API. See the property for more information on how to acquire this.
• Directory: Set this to the path which will be used to store the replicated file. If not specified, the root directory will be used.

Configure Queries for Each Azure Data Lake Storage Instance

Sync enables you to control replication with standard SQL. The REPLICATE statement is a high-level command that caches and maintains a table in your database. You can define any SELECT query supported by the Azure Data Lake Storage API. The statement below caches and incrementally updates a table of Azure Data Lake Storage data:

REPLICATE Resources;

You can specify a file containing the replication queries you want to use to update a particular database. Separate replication statements with semicolons. The following options are useful if you are replicating multiple Azure Data Lake Storage accounts into the same database:

You can use a different table prefix in the REPLICATE SELECT statement:

REPLICATE PROD_Resources SELECT * FROM Resources 

Alternatively, you can use a different schema:

REPLICATE PROD.Resources SELECT * FROM Resources

Run Sync

After you have configured the connection strings and replication queries, you can run Sync with the following command-line options:

Windows

ADLSSync.exe -g MyProductionADLSConfig.xml -f MyProductionADLSSync.sql

Java

java -Xbootclasspath/p:c:\sqlitejdbc.jar -jar ADLSSync.jar -g MyProductionADLSConfig.xml -f MyProductionADLSSync.sql