Resolving the serviceUnavailable Error in SharePoint Graph Query with Azure AD App Permissions

Описание: Discover strategies to troubleshoot and solve the `503: 'serviceUnavailable'` error when using multiple Azure AD App permissions with SharePoint Graph Queries.
---
This video is based on the question https://stackoverflow.com/q/60985658/ asked by the user 'Hans van den Akker' ( https://stackoverflow.com/u/10951944/ ) and on the answer https://stackoverflow.com/a/62749590/ provided by the user 'Sanket Ghorpade' ( https://stackoverflow.com/u/1723852/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Running into 'serviceUnavailable' SharePoint graph query forever when combining Azure AD App permissions

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding the serviceUnavailable Error in SharePoint Graph Queries

If you're using Azure Active Directory (AD) and Microsoft Graph API, you might run into an issue where your application encounters a 503: 'serviceUnavailable' error during queries. This is particularly frustrating, especially when you’re working with multiple application permissions that should, in theory, function seamlessly together. In this post, we will explore the underlying issue and offer a practical workaround to help you overcome this challenge.

The Problem

The main issue arises when multiple specific Azure AD Application permissions are assigned to your application. Despite following the proper procedure, you receive a serviceUnavailable response type when you attempt to make a query. This can be quite perplexing, especially since this should not happen under normal circumstances.

Context on the Issue

Before diving into the solution, let's briefly understand the context:

Application Permissions: The issue specifically pertains to app-only authentication, meaning that it does not involve delegated permissions. The token retrieval method is as follows:

[[See Video to Reveal this Text or Code Snippet]]

Query Execution: Once the access token is generated, the query to access SharePoint site using the following GET request could end up failing.

[[See Video to Reveal this Text or Code Snippet]]

Reproducing the Error

To understand this issue better, it might help to reproduce it through a series of deliberate steps:

Create an Azure AD Application.

Add Application Permission: Sites.ReadWrite.All.

Grant Admin Consent.

Create Secret.

Generate Access Token and run your initial query (this works, as expected).

Now, to intentionally cause the failure, follow these steps:

Add Application Permission: Group.Create.

Grant Admin Consent again.

Generate Access Token and run the query (this will likely fail).

By trying different combinations of permissions, you can isolate the permissions that are causing the serviceUnavailable error.

Diagnosing the Permissions

Some additional testing helps clarify which permissions can safely coexist without triggering the error:

Tested Combinations

With Group.Create alongside Group.ReadWrite.All and Sites.ReadWrite.All: Fails.

With only Group.ReadWrite.All and Sites.ReadWrite.All: Works without issues.

Effective Workaround

To resolve this problem without getting stuck in an endless cycle of failures, we recommend the following workaround:

Split Up Your Permissions: Divide the permissions across multiple Azure AD applications. For instance, configure one application to have Group.ReadWrite.All and another for Sites.ReadWrite.All. This way, you can still achieve your objectives without triggering the serviceUnavailable error.

Key Takeaways

It’s unnecessary to have both Group.Create and Group.ReadWrite.All; the latter suffices for most operations.

When incorporating multiple permissions, monitor for a serviceUnavailable response, and be prepared to distribute permissions across applications to maintain functionality.

Conclusion

Running into a serviceUnavailable error when combining Azure AD app permissions can halt your development progress. However, by understanding the issue and successful strategies to work around it, you can keep your application running smoothly. If you encounter this type of problem, remember to consider the organization of your permissions—it can make a world of difference for your SharePoint queries.

By following the outlined steps and insights, you can effectively manage your Azure AD Application permissions while avoiding unnecessary headaches. S