Orchestrating Services with BPEL

Course review:

Orchestrating Services

• web Service basics
• The evolution of SOAP, WSDL and UDDI
• Introducing the concepts of service orchestration
• Design principles of BPEL
• Components of the design
• Process design patterns

The Scenic tour of Process Theory

• Pi-calculus
• Petri nets
• State machines
• Activity diagrams
• BPMN and XPDL

Break the process into scopes

• How scopes are used
• Variables
• Scopes and concurrency
• Scopes and fault handling
• Transaction rollback
• Compensation

Extending the process with fault handling

• Define fault handlers for scopes
• Signal faults to the client
• Signal faults to partner services
• Inline fault handling
• Forced termination
• Suspended state usage

Add a compensation handler

• Define the scenario for compensation
• Define a compensation handler
• Invoke a compensation handler
• Rolling back a transaction
• Undoing business events

Accept more than one response from asynchronous web services

• Use pick instead of receive
• Use pick to signal faults
• Add timeouts
• Synchronous vs Asynchronous approach
• Event-driven approach

Add event handler for a scope

• Message events
• Alarm events
• Adding sensors
• Pick shape usage
• Event driven Architetcure concepts

Use dynamic partner links to invoke partner services

• Define dynamic links
• Assigning partner links
• Chaging partner links
• Choosing a service from the UDDI registry

Understanding correlation

• Define correlation manually
• Declare message properties
• Use of correlation sets
• More than 2 participants in a correlation
• Correlation and Asynchronous approach

Develop a complex parallel execution of activities

• Designing concurrency
• Controlling complex concurrent flows using links
• Implementing convoys
• Human workflow integration
• The newest version of BPEL previewed