Manage Permissions in Azure Analysis Services

Azure Analysis Services provides robust security features to control access to your data models. Managing permissions effectively ensures that users can only access the data they are authorized to see. This document outlines the different roles and permission levels available and how to configure them.

Understanding Roles and Permissions

In Azure Analysis Services, permissions are managed using roles. A role is a collection of permissions that can be assigned to users or groups. The primary roles are:

Administrator: Full control over the Analysis Services server, including managing databases, roles, and users.
Database Reader: Can view all data within a specific database.
Database Owner: Full control over a specific database, including managing its metadata, data, and roles.
Model Explorer: Can browse the metadata of a database (tables, columns, measures, etc.) but cannot view the data itself.

Managing Roles

You can manage roles directly through the Azure portal or using tools like SQL Server Management Studio (SSMS) or Azure Data Studio.

Using the Azure Portal

Navigate to your Azure Analysis Services resource in the Azure portal.
In the left-hand menu, under Settings, select Roles.
You will see a list of existing roles. You can add new roles or modify existing ones.
To add a new role, click Add role.
Enter a name for the role, select the desired permissions (e.g., Administrator, Database Reader, Owner), and add members (users or Azure AD groups) to the role.
Click Save to apply the changes.

Using SQL Server Management Studio (SSMS)

SSMS provides a familiar interface for managing Analysis Services objects.

Connect to your Azure Analysis Services server in SSMS.
In the Object Explorer, expand the Databases node and then expand the specific database for which you want to manage permissions.
Right-click on the Roles folder and select New Role....
In the Role Editor, provide a name for the role.
Under the Membership tab, add members to the role.
Under the Permissions tab, grant the necessary permissions.
Click OK to create the role.

Row-Level Security (RLS)

For more granular control, you can implement row-level security (RLS). RLS allows you to filter data based on the user's identity, ensuring they only see relevant rows.

RLS is configured by creating Row Filters within roles.

Creating Row Filters

In SSMS, connect to your Analysis Services server and database.
Right-click on an existing role or create a new one.
In the Role Editor, navigate to the Row Filters tab.
Select the table for which you want to define a filter.
In the Filter Expression field, write a DAX expression that defines the filter. For example, to restrict users to see only data for their assigned region:
```
[Region] = USERPRINCIPALNAME()
                        
```
This expression assumes a column named Region and that user principal names are formatted to match region names. You might need to adjust this based on your Azure AD structure and data.
Repeat for other tables and roles as needed.
Click OK to save the role.

Note: When using USERPRINCIPALNAME(), ensure that the format of the user principal name in Azure AD aligns with the data in your table's filter column.

Permissions for Service Principals

Service principals can also be assigned roles to allow programmatic access to your Analysis Services data. When adding members to a role, you can specify service principals by their Application (client) ID.

Tip: It is recommended to use Azure AD groups to manage role assignments. This simplifies administration by allowing you to manage group membership rather than individual user permissions.

Best Practices for Permission Management

Principle of Least Privilege: Grant users and service principals only the permissions they absolutely need to perform their tasks.
Use Azure AD Groups: Centralize user management by assigning roles to Azure AD security groups.
Regular Audits: Periodically review role assignments and permissions to ensure they are still appropriate.
Document Permissions: Maintain clear documentation of all roles, their assigned permissions, and the members.
Leverage RLS for Confidential Data: Implement row-level security to protect sensitive information within your models.

Important: Changes to role memberships or permissions may not be reflected immediately due to caching. It may take a few minutes for new assignments to become active.

By carefully managing roles and permissions, you can ensure the security and integrity of your data within Azure Analysis Services.