SOA Overview Session-2

7/31/2019 SOA Overview Session-2

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BPM, ESB,Adapters


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Introduction to BPM

BPM:

Is a technology to create a program that can invokeweb services but presents a very intuitive flow-charttype representation that can be easily understoodand modified

More technically, it is a markup language forcomposing a set of discrete services into an end-to-end process flow

BPEL Process is a web service, hence has a WSDLdocument that describes its operation

invokes operations described in interfaces in theWSDL of other services.


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Orchestration Requirements

Process orchestration coordinates services in a process from asingle run-time environment

Orchestration should enable us to create:

Business processes from services and human activities

Coarse grained business services from fine grained services Integration flows to integrate various applications

Orchestration requirements include:

Execution sequencing including serial, parallel, or other kinds ofcontrol flow dependency patterns

Exception handling including transactions and compensations

Data flow and manipulation

Event handling including timers and other out-of-band events


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BPEL Process Manager

Oracle BPEL Process Manager is implementation ofthe BPEL standard.

The Oracle BPEL Process Manager consists of thethree components. Each component enables you to

perform a specific set of tasks: The design environment (Oracle JDeveloper) enables

you to design and deploy BPEL processes.

The BPEL Server is where the process is deployed

BPEL Control can be used to run and monitor the BPELprocess


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ESB

Just like BPEL, ESB is a technology tocreate SOA Applications

An ESB project is deployed onto theESB server, just like BPEL

There are lot of similarities and some

differences between the capabilitiesof BPEL and ESB


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ESB and BPELwhen to usewhich

Basic points

ESB is useful in typical integration scenarios integrate file to DB, queue to file, Queue to DB, Appsto file, Apps to mainframe etc

BPEL is useful for orchestration scenarios bringtogether finer services into an application

Everything that ESB can do, BPEL can do too.However, ESB is faster to build and faster to execute

compared to similar integration built using BPEL.But BPEL can help develop services that may simplybe impossible to create in ESB.

BPEL has rich features like OBR, Human task, Flow,pick etc. If you require any of these, you need to use

BPEL


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Getting Customer Datausing BPEL


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ESB Capabilities


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TransformConvert data as it flows through

the bus Canonical or point-to-

point transformations

Standard XSLT forexpressingtransformations

Drag-and-drop

graphical mapping tool

Smart mapping tool,dictionary-based


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ESB Capabilities


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RouteReliably transport and route data over

a variety of protocols

Reliable messaging and guaranteed deliveryare keyin highly-distributed, asynchronous, fire-and-forget SOAwhere senders do not wait for a response.

Internally: uses JMS for asynchronous flows

On the edges: wide support of transportsSOAP,JMS, legacy messaging

Hot-pluggable transport: 3rd Party JMS, DB, J2EE


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Route: Taking Decisions

Content-based:if total_price > 500, route toFedEx

Header-based:if message_type = order, route tofulfillment

Standard XPath to definerouting expressions

Graphical expression builder


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ESB Capabilities


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Security

Main security challenges in distributed environments

Islands of security lead to security gaps

No end-to-end visibility

Developers are not necessarily security experts Modifying policies is extremely complex

ESB leverages the Oracle SOA infrastructure for security

J2EE Container (OC4J) at service level

Oracle Web Services Manager to configure global policies

No security hard-coded in endpoints

Deployment options: gateway or agent modes ESB sets and ro a ates securit headers WS-Securit


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ESB Capabilities


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Transactions & ExceptionsHandling

Submitter is in charge:

Persists messages

Resubmit

SYNCHRONOUS FLOW ASYNCHRONOUS FLOW

ESB is in charge:

Persists messages

Retries, resubmit

End-to-end transaction/XA support via JTA

Ability to set transaction boundaries

Built-in error hospital to persist and resubmit failedmessages


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ESB Capabilities


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ESB can call otherservices

ESB can call other services like BPELvia direct invocation or SOAPbindings

Direct invocation can work only whenthe ESB and BPEL servers are on sameapplication server

Direct invocation is faster BPEL can be used for process

orchestration


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ESB Capabilities


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ESB Control Overview

RoutingServices

Transformation

FilterExpression

JMSAdapter

DB

Adapter

FlowInstance

s

OverviewNavigator

BPELProcess

Manage&

Search

FlexibleErrorRetry


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ESB Server Overview

Is the runtime environment for ESBapplications (called ESB Systems)

ESB Systems are composed of a setof one or more services or adapters

The definition of ESB system iscreated in Jdeveloper and stored in

DB by ESB Metadata server At runtime, ESB Metadata server

reads these from database to create

the ESB instance in the ESB Servermemor to rocess re uests


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ESB Designer Overview

RoutingServices

Transformation

Filters

FileAdapt

erJMSAdapt

er

DBAdapt

er

JDevApplicati

on

ComponentPalette

Metadat

a WSDL XSD XSL

JDevProjec

t

Adapter

Services

Operation


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Use ESB when

Use ESB: The payload has everything needed for transforminginto the output format

Use ESB: Transformations and invocations are simple, saysequential

Use ESB: When you dont require a long running process

Use ESB: When you dont need to store data temporarily invariables

Use ESB: Memory footprint - smaller for ESB for similar project(say developing a program that reads a DB and writes a file)

Use ESB: When you want to use DVM (BPEL does support DVMsvia lookup-dvm, but its easier to use them in ESB)

Use ESB: When same or similar data needs to be sent forward.ESB is ideal for this kind of usage pattern

Use ESB: When you are not too concerned about error handlingand dont need a very tight control

Use ESB: When you need to be able to resubmit messages


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Use BPEL when

Use BPEL: Orchestration required

Use BPEL: When you need to call an asynchronous service

Use BPEL: Long-lived or chatty application

Use BPEL: Need to send notification

Use BPEL: Need to use business rules

Use BPEL: Require to split or join payloads

Use BPEL: Want to iterate over data, run a loop

Use BPEL: content validation required based on business rules

(and not necessarily xsd based) Use BPEL: when participating apps support only HTTP/XML

Use BPEL: WSDL operations having multipart in messages

Use BPEL: Need to send binary attachments

Use BPEL: Monitoring using BAM etc. BPEL offers sensors


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Whats an Adapter

An adapter provides an interface thatexposes a non Web-based applicationas Web service endpoint.

This enables the BPEL process tointeract with the service usingstandard BPEL Invoke, Receive, andReply activities

The adapters enable customers andpartners to leverage investments inexisting custom or otherwise unique

applications, and to integrate them


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Taxonomy of Adapters

Technology Adapters

Used to integrate with transport protocols, data stores,and messaging middleware

Examples file, FTP, database, JMS, AQ adapters

Packaged-Applications Adapter

Integration with packaged applications

Examples Oracle Applications adapter, Siebel adapter,Peoplesoft adapter, SAP adapter

Legacy Adapters

Integration with legacy and mainframe systems

Examples: Tuxedo adapter, CICS adapter, VSAM adapter,IMS/TM adapter, IMS/DB adapter

It is possible to create your own adapters too (custom

SOA Overview Session-2

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