Module 10: Creating Transactional Business Processes

Overview Lesson 1: Introduction to Transactions Lesson 2: Configuring Transactions

Lesson 1: Introduction To Transactions What Are Transactions? What Is Instance Persistence? Persistence Points in an Orchestration Steps for Setting Up a Transaction

What Are Transactions? Transaction Types Scope Shape Atomic — provide rollback capabilities Long-running — save state at persistence points Scope Shape Framework for transactions Enables exception handling Enables compensation handling Scope { } Drop a shape from the toolbox here

What Is Instance Persistence? State Persistence Orchestration engine manages the persistence and restoration of orchestration service instances Critical when resources required by service instances are greater than resources available Persistence Functions Dehydration and rehydration Instance recovery Transaction compensation Controlled system shutdown

Persistence Points in an Orchestration Message sent within a non-atomic scope End of transactional scope Starting a new orchestration instance (Start Orchestration shape) Debug break point Dehydration Orchestration completes System shutdown Persist State MessageBox

Steps for Setting Up a Transaction Create a scope 1 Identify the type of transaction required 2 Determine if the transaction requires compensation 3 Identify potential errors 4 Add appropriate exception handlers 5 Define compensation code 6

Lesson 2: Configuring Transactions Defining an Orchestration as Transactional Creating a Long-Running Transaction Creating an Atomic Transaction Creating Modular Business Processes Demonstration: Creating Transactions Adding Compensation Code Demonstration: Adding Compensation Code

Defining an Orchestration as Transactional Transactional orchestration Use to define an entire orchestration as transactional You can nest a long-running or atomic transaction within a transactional orchestration You cannot nest a transactional scope within an orchestration that is not transactional Set the Transaction Type property to specify the transaction type for the orchestration

Creating a Long-Running Transaction Long-running transactions Long-Running Transaction May run for an extended time Used when ACID properties are not required Data is not locked and can be modified Individual steps are committed during the transaction The transaction itself is not committed until the last statement has completed Can be nested to provide atomic components Loan application received Request Credit Report Order Appraisal Sign Documents

Creating an Atomic Transaction Atomic Transactions Guarantee rollback for transaction failures Used when ACID properties are required Isolate state changes until committed Can set entire orchestration to atomic Atomic Transaction Debit Account A Credit Account B Commit Commit

Creating Modular Business Processes Invokes another orchestration synchronously Calling orchestration waits Invokes another orchestration asynchronously Calling orchestration continues processing Call Orchestration Start Orchestration

Demonstration: Creating Transactions In this demonstration, you will see how to: Set an orchestration as transactional Add a transactional scope to an orchestration Add an exception handler to a scope

Adding Compensation Code Can be used for long-running or atomic transactions Reverses the effects of a transaction Called after the transaction has been completed Uses default compensation for nested transactions Atomic Transaction Commit Credit Account A Credit Account B Compensation Code Reverse Debit Reverse Credit

Demonstration: Adding Compensation Code In this demonstration, you will see how to: Add a compensation block to a transaction

Lab: Creating Transactional Business Processes Exercise 1: Adding Exception Handling to an Orchestration Exercise 2: Adding Compensation to an Orchestration Exercise 3: Calling Compensation Exercise 4: Testing the Application