Stardust/Knowledge Base/Transaction Management/Understanding Transaction Management in Stardust

Introduction

There is often a requirement to define units of work in a business process. The analyst may want a set of operations to be executed atomically (all-or-nothing). It is important to understand the transaction management process in Stardust to be able to define such execution semantics. It is relevant for the execution of a process to specify where a transaction starts and where it is committed. Specification of where a transaction begins and where it is committed is referred to as transaction demarcation. Transaction demarcation in Stardust is done implicitly and is compliant with the mechanisms of the EJB standard:

Normally, each call to start or continue a process demarcates the boundaries of a transaction. A two-phase commit is performed against all involved data sources after this call returns. If the client submitting this call has already demarcated a transaction, the commit may even be postponed until that point.

This article explores various transaction management scenarios under resource local and distributed transactions contexts involving the Stardust Audit Trail and external database. All artifacts referenced in the article may be downloaded from here.

Scenario

We consider a scenario where a Stardust process is kicked off and the user is prompted for some basic Employee information (Emp Id, First Name and Last Name). This data is persisted in a subsequent activity to the external data store. We simulate a TX Rollback exception by generating a PK violation from the database if the Emp Id provided already exists in the database. A Non-TX exception is generated if the Emp Id provided exceeds the value 1000.