BPEL, BPEL vs ESB (Integration)

BPELFOR BPM OR I N T EGR AT ION?

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AGENDA

BPM Definition

What is BPEL

BPEL in detail

BPEL Extensions

BPEL or Integration/ESB

BPM

a management discipline that focuses on the design of business processes and continuous improvement of the speed, cost, and quality of business operations.

emphasizes the documentation of repeatable business processes as the basis for analysis and improvement

WHAT IS BPEL

Business Process Execution Language (BPEL), short forWeb Services Business Process Execution Language (WS-BPEL) is • executable language (XML) for specifying actions within business

processes with web services

• an open standard ratified by OASIS

• Web-service interactions can be described in two ways: • as executable business processes

that models an actual behavior of a participant in a business interaction

• as abstract business processes- partially specified processes that are not intended to be executed- may hide some of the required concrete operational details

• WS-BPEL aims to model the behavior of both executable and abstract processes

!! WS-BPEL does not specify notation for diagraming (visualizing) the process

WHAT IS BPEL NOT?

• “ BPEL is block-structured only and therefore not usable for business users”

• “ BPEL does not support multiple transport protocols” - Look at WSDL

• “ BPEL interactions are only synchronous” - Look at WSDL

• “ Look at this ugly XML, business people won’t understand this cumbersome stuff”

• Not meant to be hand-written, use tools!

• BPEL is not a modeling notation

HISTORY OF BPEL

IBM’s Web Services Flow Language (WSFL)

Microsoft’s eXtensible Language (XLANG)

Original name is BPEL4WS (Business Process Execution Language for Web Services) 1.0 and 1.1.

WS-BPEL 2.0 was ratified as a standard in 2007

HISTORY OF BPEL

WHAT IS WS-BPEL 2.0 (AGAIN)

http://xml.coverpages.org/bpel4ws.html

• an XML based language enabling users to describe business process activities as Web services and define how they can be connected to accomplish specific tasks

• to specify business processes that are both composed of, and exposed as, Web Services (that are exposed using WSDL 1.1)

• an orchestration language

BPEL explanation from the OASIS

http://xml.coverpages.org/bpel4ws.html

ORCHESTRATION - CHOREOGRAPHY

An orchestration is from one actor's point of view, where choreography looks at a global system and all the actors, and their interactions, without looking at any single actor's internals.

Unlike an orchestration, there is no conductor in choreography — it is a peer to peer set of relationships.

• Orchestration• Business process with central coordinator – WS-BPEL

• Choreography• Business collaboration – WS-CDL

EXAMPLE: PURCHASE ORDER

Example in the specification document: http://docs.oasis-open.org/wsbpel/2.0/OS/wsbpel-v2.0-OS.html

On receiving the purchase order from a customer, the process initiates three paths concurrently: calculating the final price for the order, selecting a shipper, and scheduling the production and shipment for the order. While some of the processing can proceed concurrently, there are control and data dependencies between the three paths. In particular, the shipping price is required to finalize the price calculation, and the shipping date is required for the complete fulfillment schedule. When the three concurrent paths are completed, invoice processing can proceed and the invoice is sent to the customer.

Requires data from

Requires data from

IMPLEMENTATION USING DESIGNER TOOL

BPEL IN DETAIL

WEB SERVICES: BPEL 13

ReceivePurchaseOrder

ArrangeLogistics

CompleteProductionScheduling

CompletePriceCalculation

DecideOnShipper

InitiateProductionScheduling

InitiatePriceCalculation

InvoiceProcessing

Production SchedulingportType

ShippingServicesportType

InvoiceServices

portType

PurchaseOrder

portType

BPEL & WSDL



ArrangeLogistics



DecideOnShipper



InvoiceProcessing



InvoiceServices

portType

PurchaseOrder

portType

BPEL & WSDL

operation

message



ArrangeLogistics



DecideOnShipper



InvoiceProcessing



InvoiceServices

portType

PurchaseOrder

portType

BPEL & WSDL

operation

message

<portType name=“schedulingPT”<operation name=“requestProductionScheduling”>

<input message=“pos:POMessage”/></operation><operation name=“sendShippingSchedule”>

<input message=“pos:scheduleMessage”/></operation>

</portType>

STRUCTURE OF A BPEL PROCESS


Web services the process interacts with

Data used by the process

Used to support asynchronous interactions

Alternate execution path to deal with faulty conditions

Code to execute when “undoing” an action

What the process actually does

<process ...>

<partners> ...</partners>

<containers> ...</containers>

<correlationSets> ...</correlationSets>

<faultHandlers> ...</faultHandlers>

<compensationHandlers> ...</compensationHandlers>

(activities)*

</process>


BPEL AND WSDL PARTNERS

Partner A

WSDL A

Partner B

Process

WSDL


Partner A

WSDL A

Partner B

Service Link Type

BPEL AND WSDL PARTNERS

PARTNER LINKS

• Partner links are used to represent interactions (‘contract channels) between a service and each of the parties with which it interacts

• Partner links define the messages and port types used in the interactions in both directions, along with role names

• Mutual call-back dependency

• Partner Links define which partner takes which role

Key concept to enable asynchronous messaging!



A partner is accessed over a WS “channel”, defined by a service link type

A SLT defines two roles and the portTypes that each role needs to support

PARTNER DEFINITIONS AND LINKS

<partner name=“...” serviceLinkType=“...”partnerRole=“...” myRole=“...”/>

<serviceLinkType name=“...”><role name=“...">

<portType name=“...” />*</role><role name=“...”>

<portType name=“...”/>*</role>

</serviceLinkType>


“Shipping”partner link

“Invoicing”partner link

“Scheduling”partner link

“Purchasing”partner link

<partnerLink name="scheduling" partnerLinkType="lns:schedulingLT"

partnerRole="schedulingService"/>

<plnk:partnerLinkType name="schedulingLT"> <plnk:role name="schedulingService">

<plnk:portType name="pos:schedulingPT"/> </plnk:role>

</plnk:partnerLinkType>

The portType used in the partner link

PARTNER LINKS

PARTNER LINKS

Consumer

Producer

Producer

Producer


Activities represent units of processing

Flow of data is explicitly modeled through data links

Activities are mapped to application invocations or human actions

Control links define execution flow as a directed acyclic graph

TRADITIONAL FLOW MODELS


BPEL DATA MODEL

Assignment activities move data around

Activities input / output is kept in global variables

Globally scoped data variables typed as WSDL messages

<container name=“...” message=“...”/>*


Invokes an operation on a partner

Receives invocation from a partner

Sends a reply message in partner invocation

Data assignment between containers

<assign><copy>

<from container=“...”/> <to container=“...”/></copy>+

</assign>

BPEL BASIC ACTIVITIES

<invoke partner=“...” portType=“...” operation=“...”inputContainer=“...” outputContainer=“...”/>

<receive partner=“...” portType=“...” operation=“...”container=“...” [createInstance=“...”] />

<reply partner=“...” portType=“...” operation=“...”container=“...”/>


Basic Activities Structured Activities

<invoke> <sequence><receive> <while><reply> <pick><assign> <flow><throw> <scope><wait> <compensate><empty> <switch><exit> <link><catch> <if><rethrow> <repeatUntil>

<foreach>

BPEL BASIC ACTIVITIES


BPEL COMPOSITION OF WEB SERVICES

Component A

A’s WSDL

Component B

Service Link Type

B’s WSDL

Process WSDL


Detects processing error and switches into fault processing mode

Pull the plug on this instance

Execution stops for a specified amount of time

Do nothing; a convenience element

MORE BASIC ACTIVITIES

<wait for=“...”? until=“...”? />

<throw faultName=“...” faultContainer=“...”/>

<terminate/>

<empty>


<sequence>

execute activities sequentially

<flow>

execute activities in parallel

<while>

iterate execution of activities until condition is violated

<pick>

several event activities (receive message, timer event) scheduled for execution in parallel; first one is selected and corresponding code executed

<link ...>

defines a control dependency between a source activity and a target

BPEL STRUCTURED ACTIVITIES


Flow

Seq Seq

Seq

While

<sequence><receive .../><flow>

<sequence><invoke ... /><while ... >

<assign> ... </assign></while>

</sequence><sequence>

<receive ... /><invoke ... />

</sequence></flow><reply ... />

</sequence>

NESTING STRUCTURED ACTIVITIES: EXAMPLE


ASYNCHRONOUS INTERACTIONS IN BPEL

BPEL can model many types of interactions:

Simple stateless interactions

Stateful, long running, asynchronous interactions

For the latter case, how to ensure that two (or more) messages are referring to the same “session” ?


Associating two or more messages with each other in an

asynchronous environment

Done by associating contents in a given message with its correlating

message

For example, in a purchase order/invoice scenario, the invoice may

contain the corresponding purchase order number

<PurchaseOrder><PurchaseOrderNumber><PurchaseOrderDate>

........</PurchaseOrder>

Purchase Order:

<Invoice><InvoiceNumber><InvoiceDate><PurchaseOrderNumber>........

</Invoice>

Invoice:

MESSAGE CORRELATION

common in both messages


CORRELATION SETS

What is a correlation set?

A set of business data fields that capture the state of the interaction (“correlating business data”), e.g., a “purchase order number”, a “customer id”, etc.

Each set is initialized once

Its values do not change in the course of the interaction

CSs : the data used to maintain the state of the interaction (a “conversation”)

At the process end of the interaction, CSs allow incoming messages to reach the right process instance


A CS is a named set of properties. Properties are defined as WSDL extensibility elements

A property has a simple XSD type and a global name

DEFINING CORRELATION SETS

<correlationSet name=“...” properties=“...”/>

<bpws:property name=“...” type=“...” />


PROPERTIES

A property is “mapped” to a field in a WSDL message type

The property can thus be found in the messages actually exchanged

Typically a property will be mapped to several different message types and carried on many interactions, across operations and portTypes

<bpws:propertyAliaspropertyName=“...”messageType=“...” part=“...”query=“...” />


USING CORRELATION

An input or output operation identifies which correlation sets apply to the messages received or sent

That CS will be used to assure that the message is related to the appropriate stateful interaction

A CS is initialized once, in an interaction where the set appears with the “initiation” attribute set to “yes”. Its value may never be changed afterward

<receive partner=“...” operation=“...” portType=“...”container=“...”>

<correlations><correlation set=“PurchaseOrder” initiation=“yes”/>

</correlations></receive>


A customer ID and order number represent a unique purchase order

A vendor ID and invoice number represent a unique invoice

EXAMPLE: DEFINING CORRELATION SETS

<correlationSet name=“PurchaseOrder”properties=“cor:customerID cor:orderNumber”/>

<correlationSet name=“Invoice”properties=“cor:vendorID cor:invoiceNumber”/>


Declares correlation between purchase order and invoice

EXAMPLE: USING CORRELATION SETS

<invoke partnerLink=“Buyer” portType=“SP:BuyerPT”operation=“AsyncPurchaseResponse”inputVariable=“POResponse”>

<correlations> <correlation set=“PurchaseOrder”

initiate=“no” pattern=“out”><correlation set=“Invoice”

initiate=“yes” pattern=“out”> </correlations>

</invoke>


BPEL HANDLERS AND SCOPES

scopeFault Handler

CompensationHandler

A scope is a set of (basic or

structured) activities

Each scope can have two types

of handlers associated:

Fault handlers

Many can be attached,

for different fault types

Compensation handler

A single compensation

handler per scope


EB

D

C

Fault

A

SCOPE AND FAULT EXAMPLE


HOW HANDLERS WORK

A fault handler defines alternate execution paths when a fault occurs within the scope

Typical scenario:

1. Fault is thrown (retuned by invoke or explicitly by process)

2. Execution of scope is terminated

3. Appropriate fault handler located (with usual propagation semantics)

4. Main execution is compensated to “undo” business effects of unfinished work

A compensation handler is used to reverse the work performed by an already completed scope

A compensation handler can only be invoked by the fault handler or compensation handler of its immediate enclosing scope


Business processes are often of long duration, which means that a business process may need to be cancelled after many transactions have been committed during its progress

Consider a situation in which a user cancels a purchase order:

In this situation, it is not possible to lock system resources (ex: database records) for extended periods of time

Therefore, the partial work must be undone as best as possible

Submit

Purchase

Order

Process

Purchase

Order

Check

Inventor

y

Order

From

Supplier

User

Cancels!

Revert back to original state

PARTIAL WORK UNAVOIDABLE


Invoked to perform compensation activities — a “wrapper” for compensation activities:

Specifies a compensating operation on a given portType for a given partner link:

COMPENSATION HANDLERS

<compensationHandler> <invoke partnerLink=“Seller”

portType=“SP:Purchasing”operation=“CancelPurchase”inputVariable=“getResponse”outputVariable=“getConfirmation”>

<correlations> <correlation set=“PurchaseOrder” pattern=“out”/>

</correlations> </invoke>

</compensationHandler>

The CancelPurchase

operation invokes a

cancellation

The response to the

purchase request is used

as input


The relevant information about a partner service can be set up as part of business process deployment

This is a more “static” approach

However, it is also possible to select and assign partner services dynamically

BPEL uses endpoint references defined in the WS-Addressing specification for this capabilityhttp://msdn.microsoft.com/ws/2003/03/ws-addressing

DYNAMIC SERVICE SELECTION AND INVOCATION

<wsa:EndpointReference xmlns:wsa=“...”>

<wsa:Address>http://www.someendpoint.com</wsa:Address>

<wsa:PortType>PurchaseOrderPortType</wsa:PortType>

</wsa:EndpointReference>

PortType and Address assocation

BPEL EXTENSIONS

BPEL4SWS

• Support for Semantic Web Services

(Service Discovery)

• Data Mediation

BPEL light

• WSDL-less BPEL

• Is about message exchanges

BPEL JS/E4X

• Use JavaScript/E4X for variable

assignments

BPEL4People/WS-HT

• Support for Human Tasks

• Standardization Committee at

OASIS currently active

BPEL-SPE

• Support for sub-processes

• Autonomy is key

BPELJ

• Use Java in BPEL Activities

• Use Java types in BPEL

BPEL IN THE PRODUCT

BPEL sometimes includes in BPM product or Integration product like ESB (Enterprise Service Bus)

• IBM BPM Advanced (in the Process Server and considered as part of embedded ESB)• No BPEL in WebSphere ESB, IBM Integration Bus (WebSphere Message Broker)

• Microsoft BizTalk

• Oracle SOA Suite (in the BPEL Process Manager component).• No BPEL in Oracle Service Bus (OSB)

• No BPEL in BPM Suite but SOA Suite is prerequisite of BPM Suiter

• Red Hat JBoss Fuse Service Woks (FSW)• No BPEL in JBoss BPM Suite

• Currently added as optional add-on in JBoss Fuse (FSW is merged with Fuse)

• TIBCO ActiveMatrix BusinessWorks (as an optional extension)• Not included in TIBCO BPM

https://en.wikipedia.org/wiki/List_of_BPEL_engines

BPEL OR INTEGRATION

There are many more aspects, but for simplification the most important one:

• For high level business automation, like implement a purchase flow with multiple systems, long running processes (you usually need to suspend and wait until approve from manager) and business logic, you want BPEL

• If your processes are more short-term and no people are involved, you want ESB (e.g. Camel).

This not always applicable and these two worlds do not have strong boundaries, but you can simplify that.

BPEL OR INTEGRATIONOTHER VIEW

Apache Camel is one example of integration framework. It is used by several ESB product e.g. Red Hat JBoss Fuse, Apache ServiceMix, Talend ESB

ESB (e.g. Camel) is stateless (also scales better because of that), so if you need state you'd have to handle that yourself. Camel offers a few components that can help you with that though.

ESB (e.g. Camel) is payload agnostic, can be any pojo, you can even use POJOs for processing data,

BPEL processes are stateful.

BPEL uses (ultimately) xsd defined types, so a bit more complicated.

BPEL IN ORACLE PRODUCTS

History

Oracle ESB

Oracle BPEL

OSB + Mediator (Oracle ESB)

(BPEL PM)

SOA SUITE 11G

Mediator (Oracle ESB from 10g)

OSB VS ORACLE BPEL

• OSB is a 'A proven, lightweight integration Enterprise Service Bus (ESB) specifically designed for the task of integrating, virtualizing, and managing services in a shared services infrastructure, Oracle Service Bus allows you to achieve value more quickly with simple, code-free, configuration-based service integration’

• Oracle BPEL (Business Process Execution Language) Process Manager is a tool for designing and running business processes. This product provides a comprehensive, standards-based and easy to use solution for creating, deploying and managing cross-application business processes with both automated and human workflow steps – all in a service-oriented architecture

OSB VS ORACLE BPEL PM

SOA Design Pattern Oracle BPEL PM OSB

Data Model Transformation X x

Data Format Transformation x

State Repository X

Rules Centralization X x

Process Abstraction X

Process Centralization X

Asynchronous Queuing X x

Intermediate Routing x

Event-Driven Messaging X x

Protocol Bridging x

Atomic Service Transaction X

Compensating Service Transaction X

Reliable Messaging x

Policy Centralization x

https://soamythbusters.wordpress.com/2015/01/20/episode-1-bpel-vs-osb/

BPEL PM = BPEL Process Manager

WHEN TO USE OSB OR ORACLE BPEL PM

• OSB• For service virtualization and brokering activities:

• Endpoint routing (providing location transparency)

• Endpoint abstraction (interface transparency)

• Protocol conversion

• Throttling, message enrichment

• For applying policy-centralization and reliable-messaging techniques on web-services

• For stateless and short-lived web-service orchestrations

• For synchronous entity-based services or pass-through operations

• Oracle BPEL PM• Long running and stateful orchestrated tasks

• Complex composition of parallel flows that involve more than a couple of services.

• For automatizing business activities based on a process definition or process abstraction that enables us to track processes and their interactions with multiple services.

• For incorporating Human Workflow and/or Oracle Business Rules

https://blogs.oracle.com/fmwsoa/entry/oracle_soa_suite_bpel_andhttp://integrationspot.blogspot.co.id/2012/05/when-to-use-oracle-bpel-and-osb.html

https://blogs.oracle.com/fmwsoa/entry/oracle_soa_suite_bpel_and

http://integrationspot.blogspot.co.id/2012/05/when-to-use-oracle-bpel-and-osb.html

WHEN TO USE OSB OR ORACLE BPEL

• If the primary requirement is for a solutions to accomplish content based routing,transformation,message validations,enrichmentsand the integration is enterprise wide and features like message throttling,service virtualization,Reliable messaging are important,the Oracle Service Bus is a great fit .

• If the requirement is for a solution to design, manage and run business processes which are stateful with functionalities like Human Workflow, Business Rules, monitoring and management and composite service implementations, the choice should be BPEL.


RULE OF THUMB

Oracle BPEL Oracle Service Bus

Stateful and long running processes Stateless messaging capablities

Service Orchestration Service virtualization, message throttling,

configuration based service configuration,

Service pooling.

Composite implementation Message validation, content based routing,

transformation.

Integration of Rules and Human Workflow XQuery and XSLT based message transforms.


BPEL IN IBM PRODUCTS

WebSphere Process Server (WPS)WebSphere Integration Developer (WID)

WebSphere Message Broker IBM Integration Bus

WebSphereLombari Edition (BPM)

IBM BPM Advanced• IBM Process Server• IBM Integration Developer

WebSphere ESB

BPELBPEL

WebSphere DataPowerAppliance

WebSphere MQ Workflow Human task in BPEL is deprecated

BPEL IN RED HAT PRODUCTS

JBoss Fuse JBoss Fuse

BPEL

JBoss SOA Platform

Add-on (optional)Since 6.2

JBoss Fuse Service Works

BPEL

BPEL

based on Apache ODE

Current offering (Q1 2016):• Provides BPEL component within the SwitchYard (SCA)

BPEL (based on the Riftsaw project) is no longer being actively developed and will be removed from a future release of JBoss Fuse.

Red Hat recommend that you migrate BPEL to the Red Hat JBoss BPM Suite

ADDITIONAL READINGS

• BPEL or ESB: Which should you use?http://www.ibm.com/developerworks/websphere/library/techarticles/0803_fasbinder2/0803_fasbinder2.html

• BPEL vs BPMN discussion at IBM DeveloperWorkshttps://www.ibm.com/developerworks/community/forums/html/topic?id=e46b13d0-6342-4b63-bfe0-325b421f61c1

http://www.ibm.com/developerworks/websphere/library/techarticles/0803_fasbinder2/0803_fasbinder2.html

https://www.ibm.com/developerworks/community/forums/html/topic?id=e46b13d0-6342-4b63-bfe0-325b421f61c1

THANK YOU

Software

BPEL, BPEL vs ESB (Integration)