Something that we get asked about all the time when modernizing integration platforms (e.g. BizTalk to Azure), is how do we configure access from Azure to On-Premises systems (SQL Servers, File Shares, SAP, etc.) when using a Hybrid environment. The answer depends on the Azure artifacts being used. Here is a simple breakdown:

1. Azure Logic Apps: On-Premises Data Gateway

• Azure Logic Apps connects using the On-premises Data Gateway. Install the gateway on a local server (on-premises).
• Configure the Logic App connectors (e.g. SQL Server) to use the gateway.
• The data flows through the gateway securely.

2. Azure Data Factories: Self-hosted Integration Runtime

• Data Factories connects using the Integration Runtime. Install the runtime on a local server (on-premises). While the runtime concept is similar to the Data Gateway, it handles data movement at scale.
• Configure the Data Factory to use the runtime, which acts as a data movement engine.
• The runtime handles extraction, transformation and loading (ETL).

3. Azure Functions: VNet Integration + VPN/ExpressRoute or Hybrid Connections

• There are two options:
  • VNet Integration + VPN/ExpressRoute
    • Makes use of Azure VPN Gateway and Azure ExpressRoute.
    • Azure VPN Gateway is a managed hybrid connectivity service in Microsoft Azure that provides secure, encrypted network tunnels between on-premises environments and Azure virtual networks (VNets).
    • Azure ExpressRoute is a private, dedicated network connection service from Microsoft Azure that enables organizations to extend their on-premises networks into Azure data centers.
  • Hybrid Connections
    • Make use of Azure Relay Hybrid Connections.
    • Azure Relay Hybrid Connections is a feature of Azure Relay, a service within Microsoft Azure that enables secure communication between applications across network boundaries. It allows on-premises services to be accessed from the cloud without opening inbound firewall ports or modifying network infrastructure.
• The Azure Functions run in Azure with network level connectivity to on-premises systems.
• They work with any protocol.

The following table outlines key differences at a glance:

Feature	Logic Apps	Data Factory	Azure Functions
Primary Method	Data Gateway	Integration Runtime	VNet / Hybrid Connection
Setup Complexity	Low	Medium	High
Use Case	Workflows	Data pipelines	Custom code
Real-time Support	Yes	Limited	Yes
Performance	Moderate	High (batch)	High (customizable)
Flexibility	Low–Medium	Medium	Very High

For assistance using Azure Integration Services, reach out to DMS Group, we can help.