Azure Synapse¶

Note

You might want to start with our resources on data connections in the Knowledge Base.

DSS has native support for Microsoft Azure Synapse Dedicated SQL Pools (formerly known as Azure SQL Data Warehouse)

DSS supports the full range of features on Microsoft Azure Synapse

Reading and writing datasets
Executing SQL recipes
Performing visual recipes in-database
Using live engine for charts

Installing the JDBC driver ¶

Azure Synapse uses the Microsoft SQL Server JDBC driver, which can be downloaded from Microsoft website (at time of writing, from https://docs.microsoft.com/en-us/sql/connect/jdbc/download-microsoft-jdbc-driver-for-sql-server).

Make sure to select the version which is appropriate for your version of SQL Server and your version of Java. At the time of writing, these constraints are summarized here. In particular, Java 8 requires driver 4.2 or later, and Java 10 requires driver 7.0 or later.

Download the “tar.gz” distribution archive (for Unix)
Unarchive the downloaded file
Take only the “enu/mssql-jdbc-VERSION.jreX.jar”

The driver is the single JAR file called mssql-jdbc-VERSION.jreX.jar where X is the corresponding Java version.

Copy the JAR file to the lib/jdbc driver of DSS
Restart DSS

Write into Azure Synapse ¶

Loading data into Synapse using the regular SQL “INSERT” statements is very inefficient and should only be used for extremely small datasets.

The recommended way to load data into a Synapse table is through a bulk COPY from files stored in Azure Blob Storage.

DSS can automatically use this fast load method. For that, you require an Azure Blob Storage connection. Then, in the settings of the Synapse connection:

Enable “Automatic fast-write”
In “Auto fast write connection”, enter the name of the Azure Blob Storage connection to use
In “Path in connection”, enter a relative path to the root of the Azure Blob Storage connection, such as “synapse-tmp”. This is a temporary path that will be used in order to put temporary upload files. This should not be a path containing datasets.

DSS will now automatically use the optimal Azure-Blob-to-synapse copy mechanism when executing a recipe that needs to load data “from the outside” into Synapse, such as a code recipe.

Note that when running visual recipes directly in-database, this does not apply, as the data does not move outside of the database.

Explicit sync from Azure Blob Storage ¶

In addition to the automatic fast-write that happens transparently each time a recipe must write into Synapse, the Sync recipe also has an explicit “Azure Blob to Synapse” engine. This is faster than automatic fast-write because it does not copy to the temporary location in Azure Blob first.

Unload data from Synapse to Azure Blob ¶

Unloading data from Synapse directly to DSS using JDBC is reasonably fast. However, if you need to unload data from Synapse to Azure Blob, the sync recipe has a “Synapse to Azure Blob” engine that implements a faster path.

In order to use Synapse to Azure Blob sync, the following conditions are required:

The source dataset must be stored on Azure Synapse
The destination dataset must be stored on Azure Blob
The Azure Blob bucket and the Synapse cluster must be in the same Azure region

The schema of the input dataset must match the schema of the output dataset, and values stored in fields must be valid with respect to the declared Synapse column type

Login using OAuth ¶

DSS can login using OAuth on Azure Synapse. OAuth login can be performed either:

Using a single service account
Using per-user credentials. In the latter case, each user must grant DSS permission to access the database on his behalf.

Login as a single account ¶

Make sure that you have at least version 7.2 of the JDBC driver
Create a new App (Azure Portal > Azure Active Directory > App registrations). DSS will connect with the identity of this app
In the Overview tab, note the Application (client) ID
In the Overview tab, click Endpoints and note the OAuth 2.0 token endpoint (v1) URL
Create a client secret for this application (App registration > Certificates & Secrets), note the client secret
Add this app as a user in the Azure SQL Server database (see below)
Create a new SQLServer connection
Fill the “Host” and “Database” fields with the SQL Server host and database name
Enable “Login with Azure OAuth”
The STS URL is the OAuth 2.0 token endpoint (v1) URL
Client id is the application id
Client secret is the one you created earlier

Note

How to add the app as a user in the Azure SQL Server database

Before DSS can login as an app, this app must be registered as a valid user in the Azure SQL server database. This is done by entering the SQL command CREATE USER [appName] FROM EXTERNAL PROVIDER while connected as an administrator to the database.

This is technically independent from DSS, but it can be practical to do it from DSS. The difficulty is that in order to perform this command, you must be logged in as an AD user on the database.

The following procedure is provided as a best-effort help:

First, make sure that you have setup a AAD user as administrator of this database. Follow instructions here: https://docs.microsoft.com/en-us/azure/sql-database/sql-database-aad-authentication-configure
Create a new temporary SQL Server connection in DSS
- Fill the “Host” and “Database” fields with the SQL Server host and database name
- Enter the AD login/password of the AD admin user
- Add a new JDBC property with key authentication and password ActiveDirectoryPassword
- Create the connection
Create a new SQL notebook on this connection
Run the command CREATE USER [appName] FROM EXTERNAL PROVIDER with “appName” the name of the app you created previously
Delete the SQL Server connection (from now on, you’ll be logging as the app instead)

Login with per-user OAuth tokens ¶

Make sure that you have at least version 7.2 of the JDBC driver
Create a new App (Azure Portal > Azure Active Directory > App registrations). DSS will connect with the identity of this app
In the Overview tab, note the Application (client) ID
In the Overview tab, click Endpoints and note the OAuth 2.0 token endpoint (v1) URL
Go to API permissions, Add a permission, APIs my organization uses
Search for Azure SQL and add the Azure SQL Database permission, Delegated permissions, user_impersonation
Go to Authentication, and set “Default client type” > “Treat as a public client” to “Yes”. Check the “login.microsoftonline.com” URL in the “Suggested Redirect URIs” section. Save your changes.
Create a new SQLServer connection
Fill the “Host” and “Database” fields with the SQL Server host and database name
Set “Credentials mode” to “Per user”
Enable “Login with Azure OAuth”
The STS URL is the OAuth 2.0 token endpoint (v1) URL
Client id is the application id
Create the connection (you can’t test it yet)

Then for each user:

Go to user profile > connection credentials
Click the “Edit” button next to the new connection name
Follow the instructions that appear

Important: the account you log with must be a “Member” on the AAD directory. A “guest” account cannot login

Common errors ¶

Problem: when clicking on “Continue” in the OAuth setup modal, the user gets AADSTS70016: Pending end-user authorization.
Solution: the user has not completed the devicelogin registration

.

Problem: When the user goes to the devicelogin page, he gets AADSTS500113: No reply address is registered for the application.
Solution: You have not checked the “login.microsoftonline.com” URL in the “Suggested Redirect URIs” section.

.

Problem: You were able to authenticate the end-user, but connection fails with SQLServerException: Azure Active Directory is only supported on Windows operating systems.
Solution: Your driver is too old; Upgrade to 7.2 or higher

.

Problem: You were able to authenticate the end-user, but connection fails with SQLServerException: Login failed for user 'NT AUTHORITY\ANONYMOUS LOGON'.
Solution: the user account is a “Guest” on the AAD. Only “Members” are acceptable