Assess shortcut from Azure (ADLSgen2) to Fabric

  • Compare access control mechanisms between Azure and Fabric for ADLS shortcuts

  • Evaluate security implications of ADLS Gen2 shortcuts in Fabric

  • Latency consideration


Version

Date

Description

Contributor

V0.1

 

Initial document

COLOMBANI Théo







SYSM-389 - Compare access control mechanisms between Azure and Fabric for ADLS shortcuts

Key message

Access to ADLS Gen2 data through Fabric shortcuts is governed by two distinct control planes: Azure controls access to the storage target, while Fabric controls access to the shortcuted data experience. The design question is not only “who can connect”, but also “which layer authorizes what, with which identity, and at which granularity.”

Description

This section compares how access to ADLS Gen2 data is managed in Azure versus Fabric, focused on three dimensions:

DimensionAzureFabric
AuthenticationMicrosoft Entra identity, service principal, managed identity, SAS, Shared Key depending on access modeShortcut credential such as Workspace Identity, Service Principal, Organizational account, SAS, or Account Key
AuthorizationAzure RBAC plus POSIX-style ACLs on folders/filesWorkspace roles, item permissions, and OneLake security roles on folders/tables
Access scopeStorage account, container, directory, fileWorkspace, item, shortcut path, folder, table

Azure vs Fabric comparison

TopicAzure ADLS Gen2Fabric
Primary purposeProtect the storage resource itselfProtect access to data through Fabric items and experiences
Identity modelEntra users, groups, service principals, managed identitiesFabric users plus shortcut credential / workspace identity
Main authorization modelAzure RBAC + ACLWorkspace roles + item permissions + OneLake security
GranularityRBAC = broad, ACL = file/folder levelWorkspace/item = broad, OneLake security = folder/table level
Default security postureDepends on RBAC/ACL assignmentsOneLake security follows deny-by-default once enabled on the item
Non-Entra accessSAS and Shared Key supportedSAS and Account Key can be used for shortcuts, but reduce identity-based governance
Operational ownerAzure / platform / infra teamFabric / analytics / data platform team

SYSM-388 - Evaluate security implications of ADLS Gen2 shortcuts in Fabric

Shortcut-specific access model

QuestionPractical answer
Who authenticates to ADLS?The identity configured on the shortcut
Who authorizes storage access?Azure ADLS
Who authorizes visibility in Fabric?Fabric workspace/item permissions and, when enabled, OneLake security
What happens if both layers apply?The effective access is constrained by both layers; for shortcuts, Fabric documents a most-restrictive logic between shortcut path and target path
Is behavior identical across engines?

No; some scenarios use delegated identity differently, including owner-based access patterns in specific engines

Access flow

LayerWhat it controlsExamples
Fabric layerWho can see and use the shortcut inside FabricWorkspace role, item access, OneLake security
Shortcut layerWhich identity is used to reach ADLSWorkspace Identity, Service Principal, Organizational account, SAS, Account Key
Azure layerWhether the target storage path can actually be readRBAC, ACL, firewall / trusted access


Shortcut authentification models

Delegated shortcuts access data by using some intermediate credential, such as another user or an account key.

These shortcuts allow for permission management to be separated or 'delegated' to another team or downstream user to manage.

Delegated shortcuts always break the flow of security from one system to another.


Diagram showing the delegated identity used to access the data in the shortcut target.



Latency consideration

Latency view

DimensionWhat it meansShortcut impact
Exposure latencyTime to make data available in FabricLow, because no ingestion copy is required. (Microsoft Learn)
First-read latencyTime for the first query/read to access ADLS dataCan be higher than fully ingested local data because Fabric still reads the external target. (Microsoft Learn)
Repeated-read latencyTime for subsequent reads of the same dataOften improved when cache is used. (Microsoft Learn)
Refresh latencyDelay before changes in ADLS are reflectedDepends on engine and cache refresh behavior; Spark intelligent cache automatically detects underlying file changes. (Microsoft Learn)

Cache Solution for Shortcuts

Mecanism


Settings

 Shortcut caching currently supports Google Cloud Storage (GCS), S3, S3 compatible, and on-premises data gateway shortcuts.

Screenshot of workspace settings panel with OneLake tab selected.