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>AuthScheme=AccessKey;AzureStorageAccount=myAccount;AzureAccessKey=myAccessKey;</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>AuthScheme=AccessKey;AzureStorageAccount=myAccount;AzureAccessKey=myAccessKey;</ConnectionString>
 <ReplicateAll>False</ReplicateAll>
 <NotificationUserName></NotificationUserName>
 <DatabaseConnectionString>Data Source=C:\my.db</DatabaseConnectionString>
</CDataSync>

To connect with Azure Data Lake Storage, set the following connection properties:

• Connection Name: Enter a connection name of your choice.
• File Format: Select the file format you want to use. Sync supports CSV, PARQUET, and AVRO file formats.
• Azure Storage Account: Enter the name of your Azure storage account.
• URI: Enter the path of the file system and folder that contains your files (for example, adl://MyFileSystem/MyFolder).

CData Sync supports several authentication methods, including Azure Active Directory, Azure Managed Service Identity, Azure Service Principal, Service Principal Certificate, Azure Access Key, and Shared Access Signature.

Azure Access Key

To connect with an Azure access key, set the following properties:

• Auth Scheme: Select Access Key.
• Azure Access Key: Enter the access key associated with your storage account. Find it in the Azure portal under your storage account's Settings > Access keys.

For other authentication methods, refer to the Help documentation.

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 MyFolder;

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_MyFolder SELECT * FROM MyFolder 

Alternatively, you can use a different schema:

REPLICATE PROD.MyFolder SELECT * FROM MyFolder

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