Access Azure Data Lake Storage Data as OData Feeds in Tableau

The CData API Server, when paired with the ADO.NET Provider for Azure Data Lake Storage (or any of 200+ other ADO.NET Providers), provides Azure Data Lake Storage data as OData Web services. This article will explain how to use the API Server to provide the underlying connectivity to Azure Data Lake Storage data in Tableau's business intelligence tool.

Set Up the API Server

Follow the steps below to begin producing secure Azure Data Lake Storage OData services:

Deploy

The API Server runs on your own server. On Windows, you can deploy using the stand-alone server or IIS. On a Java servlet container, drop in the API Server WAR file. See the help documentation for more information and how-tos.

The API Server is also easy to deploy on Microsoft Azure, Amazon EC2, and Heroku.

Connect to Azure Data Lake Storage

After you deploy the API Server and the ADO.NET Provider for Azure Data Lake Storage, provide authentication values and other connection properties needed to connect to Azure Data Lake Storage by clicking Settings -> Connections and adding a new connection in the API Server administration console.

Authenticating to a Gen 1 DataLakeStore Account

Gen 1 uses OAuth 2.0 in 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 "Azure Active Directory".
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.

When you configure the connection, you may also want to set the Max Rows connection property. This will limit the number of rows returned, which is especially helpful for improving performance when designing reports and visualizations.

You can then choose the Azure Data Lake Storage entities you want to allow the API Server to access by clicking Settings -> Resources.

Additionally, click Settings -> Server and set the Default Format to XML (Atom) for compatibility with Tableau.

Authorize API Server Users

After determining the OData services you want to produce, authorize users by clicking Settings -> Users. The API Server uses authtoken-based authentication and supports the major authentication schemes. Access can also be restricted based on IP address; by default only connections to the local machine are allowed. You can authenticate as well as encrypt connections with SSL.

Create Real-Time Azure Data Lake Storage Data Visualizations

Follow the steps below to create data visualizations based on the remote Azure Data Lake Storage data:

1. In Tableau, select 'Connect to data'. In the 'On a server' section, click OData.

   

2. In the resulting wizard, enter the URL of the OData endpoint for the API Server. Append the name of the table you want to access to the OData entry URL. For example:

   https://your-server/api.rsc/Resources
3. Select the 'Use a Username and Password' option and enter the username and password of a user who has access to the API Server.

4. Tableau uses the table metadata exposed by the API Server to detect dimension and measure columns.

   

5. To view the Azure Data Lake Storage data, right-click under the table name in the Data section of the dashboard and select the View Data option. The Azure Data Lake Storage data will appear in Tableau.