IBM WebSphere survey Kristian Bisgaard Lassen

University of AarhusIBM WebSphere survey2 Tools  WebSphere Application Server Portal Studio Business Integration Server

University of AarhusIBM WebSphere survey3 BPEL4WS (abbr. BPEL)  Business Process Execution Language for Web Services (OASIS specification)  XML syntax and typed by XML Schema  Mapped to EJB components

University of AarhusIBM WebSphere survey4 Example of BPEL

University of AarhusIBM WebSphere survey5 Modeling features  Sequencing (dashed arrow)  Concurrency (free grouping)  Synchronization (solid arrow)  Hierarchy (sub process)  Reuse (instances)

University of AarhusIBM WebSphere survey6 WSDL description  Web Service Definition Language  Port type Describes the operations the process supports  Operation Defined by input and output messages  Both does not need to be defined Similar to a function declaration

University of AarhusIBM WebSphere survey7 BPEL general  Describes processes by what activities they perform and which processes they interact with  Visualization of a BPEL process can be done in several ways in contrast to e.g. state charts

University of AarhusIBM WebSphere survey8 Basic activity content (1)  Name  Join condition Default expression is a logic OR of link status of incoming links Can be defined as any Boolean expression  Suppress join failure (yes | no)

University of AarhusIBM WebSphere survey9 Basic activity content (2)  Source links Optional transition condition  Target links

University of AarhusIBM WebSphere survey10 Basic activity content (3)  All activities can have event handlers  Event handlers are invoked concurrently with the activity  Semantics of event handlers are similar to that of the Pick activity

University of AarhusIBM WebSphere survey11 BPEL process activities (1)  Receive Blocking wait for a message  Reply Constructs a message to a message received in a Receive activity

University of AarhusIBM WebSphere survey12 BPEL process activities (2)  Invoke Allows a process to invoke a one-way operation on a port type offered by a partner Possible to specify  Exception handlers  Compensation handlers

University of AarhusIBM WebSphere survey13 BPEL process activities (3)  Assign Update variables with data  Throw Generate a named exception  Wait Makes the process wait for a certain period of time

University of AarhusIBM WebSphere survey14 BPEL process activities (4)  Empty No operation Useful for  Synchronization  Suppressing exceptions  Sequence Perform activities sequentially  Switch Allows conditional branching

University of AarhusIBM WebSphere survey15 BPEL process activities (5)  While Perform a certain activity until a condition is meet  Pick Blocking activity waiting for a message or an ‘alarm’ to go off  Flow Construct allows one or more activity to be performed concurrently

University of AarhusIBM WebSphere survey16 BPEL process activities (6)  Scope A nested activity  Compensate Fault handler for scoped activities

University of AarhusIBM WebSphere survey17 Process lifecycle  BPEL4WS processes are long running stateful interactions  Process instantiation is implicit  Termination can happen if The activity completes normally A fault is reached in the process scope Explicit termination

University of AarhusIBM WebSphere survey18 Partner links (1)  The type characterizes relationship between two services by roles (e.g. buyer and seller) A role specifies a WSDL port type  Partner link is an instantiation of a partner link type  Partners can be selected both statically and dynamically through assignment (Assign)

University of AarhusIBM WebSphere survey19 Partner links (2)  Business partner A subset of a partner link type  Endpoint reference Dynamical reference of port. Used typically when a certain instance of a service is needed

University of AarhusIBM WebSphere survey20 Business Process Choreographer  BPEL processes can be contained in BPC  BPC add to BPEL staff activities Activities which requires human interaction

University of AarhusIBM WebSphere survey21 Staff activity  When a staff activity is invoked work items are generated  A role can have three roles Potential owner  Can claim the activity, complete it or transfer it to another potential owner Editor  Can add information to the work item but not complete it Reader  Can only check the work item status

University of AarhusIBM WebSphere survey22 BPEL+  WebSphere specific  Integrated with Java, e.g. in Variable type declarations Transition conditionals In Invoke constructs

University of AarhusIBM WebSphere survey23 WebSphere Studio (1)

University of AarhusIBM WebSphere survey24 WebSphere Studio (2)

University of AarhusIBM WebSphere survey25 WebSphere Studio (3)

University of AarhusIBM WebSphere survey26 Future work  Develop a running example of something in WebSphere Studio  Port the Bankdata model to BPEL or BPEL+ in WebSphere Studio  Compare BPEL to the Eindhoven business flow model  Investigate ways to restrict CPN models so they can translate to BPEL