🔗 Azure Logic Apps
★ Serverless workflow automation — no-code/low-code integration and B2B orchestration
Table of Contents
- Product Overview
- Hosting Models
- Connectors
- Stateful vs Stateless Workflows (Standard only)
- B2B & Enterprise Integration
- Error Handling & Reliability
- Security
- Logic Apps vs Azure Functions vs Power Automate
- Common Exam Scenarios
Product Overview
Azure Logic Apps is a serverless, cloud-based workflow automation service that lets you build automated workflows connecting applications, data, services, and systems — with minimal or no code. It uses a visual designer with 500+ pre-built connectors covering Azure services, SaaS applications (Salesforce, Office 365, ServiceNow), on-premises systems, and custom HTTP endpoints.
Logic Apps is Azure’s answer for business process automation, enterprise integration (EAI), B2B trading partner workflows, and light orchestration — where teams prefer no-code/low-code over writing Functions code.
flowchart LR
subgraph Triggers["Triggers"]
HTTP["HTTP Request\n(webhook)"]
REC["Recurrence\n(schedule)"]
SB["Service Bus\nmessage"]
O365["Office 365\nnew email"]
SF["Salesforce\nnew record"]
end
subgraph WF["Logic App Workflow"]
direction TB
T["Trigger"]
A1["Action: Condition"]
A2["Action: Parse JSON"]
A3["Action: Send Email"]
A4["Action: Write to SQL"]
T --> A1 --> A2 --> A3
A2 --> A4
end
subgraph Conn["Connectors (500+)"]
AZURE["Azure Services\n(Storage, SQL, Event Hubs)"]
SAAS["SaaS\n(Salesforce, SAP, ServiceNow)"]
ONPREM["On-premises\n(SQL, File, SAP via gateway)"]
CUSTOM["Custom\n(HTTP, OpenAPI)"]
end
Triggers --> WF
WF --> Conn
Hosting Models
Logic Apps has two hosting models with significant differences — this is the most exam-tested distinction:
| Feature | Consumption | Standard |
|---|---|---|
| Hosting | Multi-tenant, fully managed | Single-tenant, Azure App Service-based |
| Workflows per instance | 1 workflow per Logic App | Multiple workflows in one Logic App |
| Pricing | Per action execution | Per App Service Plan hour + execution |
| VNet Integration | ❌ | ✅ |
| Private Endpoints | ❌ | ✅ |
| On-premises connector | Via Data Gateway (agent-based) | Via VNet Integration (direct) |
| ISE (Integration Service Environment) | Replaced by Standard | N/A |
| Stateful workflows | ✅ | ✅ |
| Stateless workflows | ❌ | ✅ |
| Deployment | Portal / ARM / Bicep | Portal / ARM / VS Code / CI-CD |
| SLA | 99.9% | 99.95% |
| Built-in connectors | Limited set | Extended set (run in-process) |
⚠️ Exam Caveat — ISE is Retired: The Integration Service Environment (ISE) was retired in August 2024. All ISE capabilities (VNet injection, dedicated resources, private endpoints) are now delivered by Logic Apps Standard. If an exam question references ISE for VNet connectivity, the modern answer is Logic Apps Standard.
⚠️ Exam Caveat — VNet Connectivity: If the scenario requires Logic Apps to connect to private resources (SQL MI, on-premises systems without a public endpoint, internal APIs), the answer is Logic Apps Standard — not Consumption. Consumption can only reach public endpoints or use the on-premises Data Gateway.
Connectors
Connectors are grouped into categories:
| Category | Examples | Notes |
|---|---|---|
| Built-in | HTTP, Schedule, Request, Azure Functions, Service Bus | Run in-process; faster, no connection management |
| Managed (Azure-hosted) | Office 365, Salesforce, SharePoint, SQL, Blob | Hosted in Microsoft’s multi-tenant connector service |
| On-premises | SQL Server, File System, SAP, Oracle | Require On-premises Data Gateway (Consumption) or VNet (Standard) |
| Enterprise | SAP, IBM MQ, IBM 3270 | Premium connectors; licensed separately |
| Custom | OpenAPI spec, HTTP webhooks | Bring-your-own connector via OpenAPI |
⚠️ Exam Caveat — On-premises Data Gateway: For Consumption plan to reach on-premises systems, the On-premises Data Gateway must be installed on a machine with network access to the on-premises resource. It acts as a relay agent. Standard plan does not need the gateway if VNet Integration is configured.
Stateful vs Stateless Workflows (Standard only)
| Mode | State Storage | Use Case | History |
|---|---|---|---|
| Stateful | State stored in external storage (Azure Storage) | Long-running, reliable, survives restarts | Full run history available |
| Stateless | In-memory only | Low-latency, short-duration workflows | No persistent history |
⚠️ Exam Caveat — Stateless Workflows: Stateless workflows in Logic Apps Standard are faster and cheaper but have no replay, no history, and no persistence — a restart loses state. Use stateless for workflows that complete in seconds and do not require auditing.
B2B & Enterprise Integration
Logic Apps is Azure’s primary platform for B2B trading partner integration and enterprise application integration (EAI):
| Feature | Detail |
|---|---|
| Integration Account | Repository for B2B artefacts: partners, agreements, schemas, maps, certificates |
| EDI | AS2, X12, EDIFACT message exchange with trading partners |
| XML processing | XML validation, XSLT transformation, XPath extraction |
| Flat file encoding/decoding | Convert flat files to/from XML |
| RosettaNet | Industry-specific B2B protocol support |
⚠️ Exam Caveat — Integration Account Tiers:
Tier Use Case Price Free Dev/test; limited throughput Free Basic Receive-only trading partners, simple transformations Low Standard Full B2B: EDI, XSLT maps, complex schemas Standard Integration Account must be linked to a Logic App (Consumption or Standard) to use B2B connectors.
Error Handling & Reliability
| Feature | Detail |
|---|---|
| Run After | Configure actions to run after Success, Failure, Timeout, or Skipped — enables try/catch patterns |
| Retry policies | Built-in retry with configurable interval and count per action |
| Dead-lettering | Failed runs are logged with full input/output for debugging |
| Correlation | Track related runs via correlation IDs |
| Timeout | Per-action and per-run timeouts configurable |
Try / Catch Pattern
[Action: Call API] ← configure "Run After" = Success
↓ (on failure)
[Scope: Error Handler] ← configure "Run After" = Failed, TimedOut
↓
[Action: Send Alert Email]
[Action: Log to Storage]
Security
| Feature | Detail |
|---|---|
| Managed Identity | Authenticate to Azure services without storing credentials in connector config |
| IP restrictions | Restrict inbound trigger calls to specific IPs or service tags |
| SAS-secured HTTP trigger | Generated SAS token in the trigger URL; expires or can be regenerated |
| Obfuscate inputs/outputs | Mark sensitive parameters as Secure String — hidden in run history |
| Private Endpoints | Logic Apps Standard only; inbound calls from VNet only |
| Key Vault integration | Reference secrets from Key Vault in connection strings |
Logic Apps vs Azure Functions vs Power Automate
| Aspect | Logic Apps | Azure Functions | Power Automate |
|---|---|---|---|
| Target user | Developer / IT Pro | Developer | Business user |
| Coding required | No (visual) | Yes (code) | No (visual) |
| Custom logic complexity | Medium | High | Low |
| Connectors | 500+ managed | Custom + bindings | 500+ (same as LA) |
| B2B / EDI support | ✅ | ❌ | ❌ |
| Long-running workflows | ✅ (days/weeks) | ✅ (Durable) | ✅ |
| VNet integration | ✅ (Standard) | ✅ (Premium) | ❌ |
| Pricing | Per action / per plan | Per execution | Per user/flow |
⚠️ Exam Caveat — Logic Apps vs Functions: Use Logic Apps when the workflow is connector-heavy, visual, or B2B-oriented. Use Functions when the logic requires complex code, custom algorithms, or tight performance control. They are complementary — a Logic App can call a Function for complex logic steps.
Common Exam Scenarios
| Scenario | Answer |
|---|---|
| Automate email-to-SharePoint document workflow, no code | Logic Apps Consumption |
| Logic App must call an on-premises SQL Server (private) | Logic Apps Standard + VNet Integration |
| EDI X12 B2B trading partner integration | Logic Apps + Integration Account (Standard) |
| Try/catch error handling in a Logic App | Scope + Run After = Failed |
| VNet-isolated Logic App replacing ISE | Logic Apps Standard |
| Low-latency, in-memory, short workflow, no history needed | Logic Apps Standard — Stateless workflow |
| Multiple workflows in one deployment unit | Logic Apps Standard |
| Complex custom algorithm in a workflow step | Logic Apps calling an Azure Function |
| Schedule a weekly report email from Office 365 | Logic Apps Consumption + Recurrence trigger |
| Cheapest per-execution B2B integration at low volume | Logic Apps Consumption |