Extend Microsoft Sentinel across workspaces and tenants

When you onboard Microsoft Sentinel, your first step is to select your Log Analytics workspace. While you can get the full benefit of the Microsoft Sentinel experience with a single workspace, in some cases, you might want to extend your workspace to query and analyze your data across workspaces and tenants. For more information, see Design a Log Analytics workspace architecture and Prepare for multiple workspaces and tenants in Microsoft Sentinel.

If you onboard Microsoft Sentinel to the Microsoft Defender portal, see Microsoft Defender multitenant management.

Manage incidents on multiple workspaces

Microsoft Sentinel supports a multiple workspace incident view where you can centrally manage and monitor incidents across multiple workspaces. The centralized incident view lets you manage incidents directly or drill down transparently to the incident details in the context of the originating workspace.

Query multiple workspaces

Query multiple workspaces to search and correlate data from multiple workspaces in a single query.

  • Use the workspace( ) expression, with the workspace identifier as the argument, to refer to a table in a different workspace.

  • Use the union operator alongside the workspace( ) expression to apply a query across tables in multiple workspaces.

  • Use saved functions to simplify cross-workspace queries. For example, you can shorten a long reference to the SecurityEvent table in Customer A's workspace by saving the expression:

    workspace("/subscriptions/<customerA_subscriptionId>/resourcegroups/<resourceGroupName>/providers/microsoft.OperationalInsights/workspaces/<workspaceName>").SecurityEvent
    

    as a function called SecurityEventCustomerA. You can then query Customer A's SecurityEvent table with this function: SecurityEventCustomerA | where ... .

  • A function can also simplify a commonly used union. For example, you can save the following expression as a function called unionSecurityEvent:

    union 
    workspace("/subscriptions/<subscriptionId>/resourcegroups/<resourceGroupName>/providers/microsoft.OperationalInsights/workspaces/<workspaceName1>").SecurityEvent, 
    workspace("/subscriptions/<subscriptionId>/resourcegroups/<resourceGroupName>/providers/microsoft.OperationalInsights/workspaces/<workspaceName2>").SecurityEvent
    

    Then, write a query across both workspaces by beginning with unionSecurityEvent | where ... .

Include cross-workspace queries in scheduled analytics rules

You can include cross-workspace queries in scheduled analytics rules. You can use cross-workspace analytics rules in a central SOC, and across tenants (using Azure Lighthouse), suitable for MSSPs. This use is subject to the following limitations:

  • You can include up to 20 workspaces in a single query. However, for good performance, we recommend including no more than 5.
  • You must deploy Microsoft Sentinel on every workspace referenced in the query.
  • Alerts generated by a cross-workspace analytics rule, and the incidents created from them, exist only in the workspace where the rule was defined. The alerts won't be displayed in any of the other workspaces referenced in the query.
  • A cross-workspace analytics rule, like any analytics rule, will continue running even if the user who created the rule loses access to workspaces referenced in the rule's query. The only exception to this is in the case of workspaces in different subscriptions and/or tenants than the analytics rule.

Alerts and incidents created by cross-workspace analytics rules contain all the related entities, including those from all the referenced workspaces and the "home" workspace (where the rule was defined). This way, analysts get a full picture of alerts and incidents.

Note

Querying multiple workspaces in the same query might affect performance, and therefore is recommended only when the logic requires this functionality.

Use cross-workspace workbooks

Workbooks provide dashboards and apps to Microsoft Sentinel. When working with multiple workspaces, workbooks provide monitoring and actions across workspaces.

Workbooks can provide cross-workspace queries in one of three methods, suitable for different levels of end-user expertise:

Method Description When should I use?
Write cross-workspace queries The workbook creator can write cross-workspace queries (described above) in the workbook. I want the workbook creator to create a workspace structure that is transparent to the user.
Add a workspace selector to the workbook The workbook creator can implement a workspace selector as part of the workbook. I want to allow the user to control the workspaces shown by the workbook, with an easy-to-use dropdown box.
Edit the workbook interactively An advanced user modifying an existing workbook can edit the queries in it, selecting the target workspaces using the workspace selector in the editor. I want to allow a power user to easily modify existing workbooks to work with multiple workspaces.

Hunt across multiple workspaces

Microsoft Sentinel provides preloaded query samples designed to get you started and get you familiar with the tables and the query language. Microsoft security researchers constantly add new built-in queries and fine-tune existing queries. You can use these queries to look for new detections and identify signs of intrusion that your security tools might have missed.

Cross-workspace hunting capabilities enable your threat hunters to create new hunting queries, or adapt existing ones, to cover multiple workspaces, by using the union operator and the workspace() expression as shown above.

Manage multiple workspaces using automation

To configure and manage multiple Log Analytics workspaces enabled for Microsoft Sentinel, you need to automate the use of the Microsoft Sentinel management API.

Manage workspaces across tenants using Azure Lighthouse

As mentioned above, in many scenarios, the different Log Analytics workspaces enabled for Microsoft Sentinels can be located in different Microsoft Entra tenants. You can use Azure Lighthouse to extend all cross-workspace activities across tenant boundaries, allowing users in your managing tenant to work on workspaces across all tenants.

Once Azure Lighthouse is onboarded, use the directory + subscription selector on the Azure portal to select all the subscriptions containing workspaces you want to manage, in order to ensure that they'll all be available in the different workspace selectors in the portal.

When using Azure Lighthouse, it's recommended to create a group for each Microsoft Sentinel role and delegate permissions from each tenant to those groups.

Next step

In this article, you learned how Microsoft Sentinel's capabilities can be extended across multiple workspaces and tenants. For practical guidance on implementing Microsoft Sentinel's cross-workspace architecture, see the following articles: