Microsoft SQL Server

DSS supports the full range of features on Microsoft SQL Server:

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

Installing the JDBC driver

The SQL Server JDBC driver 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

Azure DataWarehouse mode

DSS has experimental support for the Azure Data Warehouse. Configure a Azure Data Warehouse connection by enabling the “Azure Data Warehouse” option of a SQL Server connection

Warning

This option must only be used for “Azure Data Warehouse” databases. You must not use this option for regular SQLServer databases hosted on Azure.

Setting the “Azure Data Warehouse” option on a regular SQLServer database will result in a non-functional connection

Warning

Writing data to a Azure Data Warehouse dataset is slow (apart from the case where the input is on the same database and the recipe uses the SQL / In Database engine)

Importing data to Azure Data Warehouse can be speed up by using an Azure Blob Storage as data source and selecting “Azure to SQLServer” as recipe engine.

Warning

When using the Azure to SQLServer engine, discrepancies may appear in strings if the use of quote characters is not coherent throughout the input dataset.

Kerberos authentication

In default connection mode, DSS authenticates to SQL Server by way of a username and password defined in the connection configuration page.

Alternatively, it is possible for DSS to connect to the database with Kerberos authentication, provided a number of prerequisites are met:

  • Kerberos authentication should be enabled on the SQL Server

  • The Kerberos client configuration file (typically /etc/krb5.conf) should be correctly configured on the DSS host.

  • Create a Kerberos account for DSS on the KDC (or domain controller) and note the Kerberos principal for it, say DSSKerberosPrincipal@KERBEROS.REALM.

  • Create a keytab file for this account, and store it in a file accessible only to DSS.

  • At the DSS level, configure the SQL Server connection as follows:

    • Login with Kerberos: enabled

    • Principal: the Kerberos principal created above

    • Keytab: absolute path to the keytab file for this Kerberos principal

    • Advanced JDBC properties: add any SQLServer-specific advanced connection properties required by your database setup. This would typically be:

      integratedSecurity : true
      authenticationScheme : JavaKerberos
      # the following is needed only if the database server service principal name (SPN)
      # is different from the default : MSSQLSvc/FQDN:[email protected]
      serverSpn : SERVER_SPN
      

User impersonation with Kerberos

Note

While this feature is distinct from the User Isolation Framework feature, it is only available for DSS licenses that enable the User Isolation Framework.

This feature requires DSS to run under Java 8

This feature requires the database server to be integrated with a Windows Active Directory domain controller.

It is possible to configure DSS to authenticate to the database using one database account, and perform all data manipulation and SQL queries using another. This typically allows DSS to impersonate its end-users when accessing the database, much as is done for Hadoop or local computations when running in User Isolation Framework mode.

At the DSS level, this is configured by entering the database account name to impersonate in the Impersonated user field of the connection configuration page.

Typical uses of this feature would include:

  • defining this field as %{dssUserLogin} to directly use the DSS user login name as SQLServer account name, in case the DSS and SQLServer account databases match one-for-one
  • defining this field as %{adminProperty:sqlServerLogin} where sqlServerLogin is a custom per-user admin property defined in the DSS user database, in the more general case where usernames have to be remapped

This impersonation mechanism uses the Active Directory “constrained delegation” feature, and should have been authorized accordingly by the domain administrator. This is typically done as follows (refer to Microsoft documentation for details):

  • Add a Service Principal Name to the Active Directory service account used by DSS. This is typically done with setspn, or directly with the ktpass command when creating the Kerberos keytab for DSS
  • In the “Active Directory Users and Computers” tool, open the DSS service account entry, and select the “Delegation” tab (this tab is only visible for accounts which have a SPN set).
  • Check “Trust this user for delegation to specified services only”
  • Check “Use any authentication protocol”
  • Locate or search for the SQL server service entry, and allow the DSS account to delegate to it.

Login using OAuth on Azure SQL Server

DSS can login using OAuth on Azure SQL Server. 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

s* 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 regizstration

.

  • 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