Transcript EGL Integration with Web Services

© 2009 IBM Corporation
IBM Software Group
EGL Integration with COBOL and Web Services
Mark Evans ([email protected])
EGL Development
®
IBM Software Group | Rational software
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Agenda

Brief Introduction to Web Services

RBD/EGL – A tool for Building Web Services

Options for EGL Integration with COBOL Web Services
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Enterprise Modernization – Why Web Services ?
 Web services provide standardized access to assets
for different software applications residing on
disparate platforms
 Web service definitions provide abstract interfaces
which allow for loose coupling between business
components – implementation can vary without
affecting consumers
 You can reuse applications exposed as Web services
in a variety of service-oriented architecture
frameworks, such as a process choreographer or an
enterprise service bus.
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Enterprise Modernization and Web Services
 Basic Problem Statement:
 An Existing COBOL program on CICS contains the business/data logic for a business
transaction
 A requestor/client outside CICS needs to obtain this information
 Solution
 Create Web Service to “front end” the called program
 Provides standard interface
 Many tools work with and can access web services
CICS TS 3.x or Later
Requester
Needs info
From CICS
Web Service
Callable
COBOL
Program
DB2
Or
Files
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Enterprise Modernization and Web Services – Getting Started
 What’s Required?
1.
Standard Definition of the Services interface

SOAP format to contain the messages going back and forth

WSDL (Web Services Definition Language) to define the message content
2.
3.
A Web service (SOAP message) processor such as one of the following:

WebSphere Application Server

CICS

Tomcat

Other application servers
Tools to help build the necessary interfaces and work with the runtimes
CICS TS 3.x or later
CICS
Web
Service
Runtime
Callable
COBOL
Program
DB2
Or
Files
SOAP Message/WSDL
Requester
Needs info
From CICS
Web Service
WebSphere
Web Service
Support
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Agenda

Brief Introduction to Web Services

RBD/EGL – A tool for Building Web Services

Options for EGL Integration with COBOL Web Services
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EGL Services Support – High Level View
At development time…
focus on the business logic
implement SOA design elements: Services & Interfaces
leverage existing COBOL or RPG developers for new SOA
development
ignore deployment targets/technology while coding/testing
Use Deployment Descriptor file to describe Deployment
considerations
Use existing non-EGL Web Service
Create EGL Interface and EGL Records
automatically based on existing WSDL
EGL
RUI/JSF/TUI
EGL
Interface
EGL
Records
EGL
Records
EGL
Service
W
S
D
L
Build & expose EGL Web Service
Non-EGL
User of
EGL Service
W
S
D
L
Existing
Service
EGL applications invoke
operations in EGL Interface and
send Records as parameters
Deploy EGL Services…
in Java to Java to WAS, Tomcat, Win, Linux, HP-UX,
Solaris, iSeries
in COBOL to CICS, System i
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Service Part – Built into the language

A service is similar to a library,
with the major exception that a
service may be located remotely
from its client.

The client – which can be a
program, JSF handler, library, or
other service - uses (invokes)
the functions defined in the
service.

Services have one or more
public functions that contain
business logic. Once you have
written the business logic, you
can deploy the service as one of
the following:
 an EGL Java™ service
 a Web service
 an EGL COBOL service
 a CICS® Web Service

In general, you create a Service
part when you want to make
your business logic available to
other programs, either locally or
remotely, in an encapsulated
way.
Example of an EGL Service
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EGL Interfaces - Concepts built into the language
SOA
 Interface part
Provides abstract definition of Service
Can be created directly from WSDL for use by Web Service clients
Access external services as EGL services
Interface IStockQuoteService
Function getQuote(symbol String) returns (money);
end
Service StockQuoteService implements IStockQuoteService
Function getQuote(symbol String) returns (money)
…
end
end
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EGL Services – EGL Deployment Descriptor Files

EGL Deployment
Descriptor files are used
to describe how EGL
service applications are
bound to the clients that
call them, and vice versa
 Generates wrapper
program for each service

Service Client Bindings
 How to invoke the
service

Services Deployment
 How the service is
invoked

Sharable Protocols
 Common information for
clients and services
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Agenda

Brief Introduction to Web Services

RBD/EGL – A tool for Building Web Services

Options for EGL Integration with COBOL Web Services
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RBD/EGL SOA Integration with Enterprise Programs – Options
CICS TS 3.x or later
Web Service Based
Option 1
Channel
Web Service Based
Option 2
EGL and non-EGL client
CICS
Web
Service
Runtime
Callable
COBOL/EGL
Program
Cobol Call
Channel
Web Service
Requester
RDz
Generated
Handlers
SOAP Message
EGL
COBOL Cobol Call
Web Service
Wrapper
EGL
COBOL
Service
WSDL
Service Invocation
WebSphere
Call Interface Based
Option 3
EGL
Client
CICSECI or CICS J2C
Call Statement
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RBD/EGL SOA Integration – Option 1
EGL Integration with RDz Generated WSDL/Handlers
Web Service Based
Option 1
Web Service
Requester
SOAP Message
CICS TS 3.x or later
CICS
Web
Service
Runtime
Channel
RDz
Generated
Handlers
Callable
COBOL/EGL
Program
Cobol Call
WSDL
EGL and non-EGL client
 Use Rational Developer for zSeries tools to:
 Create WSDL and/or WSBIND needed by CICS Web Services Runtime
 Create COBOL “wrappers” to front end the COBOL program
 More on this later
 Use EGL to:
 Create an EGL interface from the RDz generated WSDL
 Create a client binding (how to invoke the service) in the EGL deployment Descriptor
 Create a EGL Client (e.g. Service) to invoke this interface
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Create web services for zOS runtimes – RDz* Tooling
 Build, Deploy, and Test Web services from existing
applications
 Create source code skeletons from web service
definitions
 Map web service definitions to existing application
modules
 Supports traditional languages
 COBOL
 PL/I
 Supports zOS specific runtimes
 CICS
 IMS
 Batch
*RDz = Rational Developer for system z
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Consuming EGL Web Services – Create Interface and Client bindings

Copy the WSDL from RDz into the EGL project

Select the WSDL file and choose:
1.
“Create EGL Client Interface”
2.
Choose which web service you want to interface with
(Next)
3.
Choose (filled in for you based on WSDL)
4.

Location of source

Which functions to interface with
Click “Next” to specify client bindings
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Consuming non-EGL Web Services – Resulting Definitions



Need to fill in URI with URL used to invoke the web service
–
http://<hostname>:<soaplistenerport>/<relativepathofservice>
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EGL CICS Web Service Client
CICS TS 3.1
EGL COBOL
Program
or
Service
(including
3270 pgms)
Cobol Call
COBOL
Web Service
Proxy
Channel
CICS
Web
Service
Runtime
SOAP Message
Service
Provider
HFS
WSDL
WSBIND
 Generated from the EGL deployment Descriptor (web service client bindings)
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RBD/EGL SOA Integration – Option 2
Using EGL Web Services to create new logic or wrapper existing programs
CICS TS 3.x or later
Web Service Based
Option 2
Web Service
Requester
SOAP Message
WSDL
EGL and non-EGL client
CICS
Web
Service
Runtime
Callable
COBOL/EGL
Program
Cobol Call
Channel
EGL
COBOL Cobol Call
Web Service
Wrapper
EGL
COBOL
Service
 Use RBD/EGL to:
 Create a service part (see previous slides)
 Service part calls native COBOL program
 Add EGL Service Binding information to the EGL Deployment Descriptor
 Generate EGL service and Deployment Descriptor which creates
 WSDL and WSBIND needed by CICS Web Service Runtime
 COBOL modules to implement the EGL COBOL web service
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EGL CICS Web Services – Generation Process
Deployment
Descriptor file
HFS
WSBIND
(.egldd file)
WSDL
Build Descriptor file
EGL Build
(.eglbld file)
Server
CICS
Generation
Services Source
z/OS
(.egl files)
PDS w/Load
Modules
Workstation
z/OS
 Deployment Descriptor File  WSBIND, WSDL, & Wrapper COBOL programs
 Services  COBOL program
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EGL CICS Web Services – Deploying Service on CICS
 For resulting load modules:
 In CICS DFHRPL;


Add PDS with load modules for service and service wrapper
Add EGL COBOL Runtime library
 In CICS CSD


Add CICS Program entries (unless dynamically created)
Add any required DB2 related entries if program accesses DB2
 Install CICS groups/entries as necessary
 Perform CICS NEWCOPY if replacing existing load modules
 For Web Services Infrastructure:
 Add CICS Pipeline Entry to specify target HFS directories that generation writes to
(one time if you want to always generate to same HFS directory)
 Perform a CEMT P PIPELINE SCAN to:



Enable the Pipeline
Create WebService entry based on information in generated WSBIND file
Create URIMAP entry based on information in generated WSBIND file
NOTE: CICS Userid must have permission to write to HFS directories specified in Pipeline definition
 If using Transaction other than CPIH in Web Service Entry



Recommended if using EGL generated Web Service
Still must be associated with same program example as CPIH
Can be done by CEDA COPY command:
–
CEDA COPY TRANSACTION(CPIH) GROUP(DFHPIPE) AS(<newname>) TO(<group>)
 Install CICS group/entries as necessary
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RBD/EGL SOA Integration – Option 3
EGL Services and Call Interface
CICS TS 3.x or later
EGL and non-EGL client
Callable
COBOL/EGL
Program
CICS
Web
Service
Runtime
Cobol Call
Channel
Web Service
Requester
SOAP Message
EGL
COBOL Cobol Call
Web Service
Wrapper
EGL
COBOL
Service
WSDL
Service Invocation
WebSphere
Call Interface Based
Option 3A and 3B
EGL
Client
CICSECI or CICS J2C
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EGL Services for CICS (Option 3A)
 EGL also has the concept of an EGL service
 Which is:
 Accessing the generated service directly using
– CICS ECI (remote invocation)
– CICS JCA/J2C (remote invocation)
– COBOL Calls
 From EGL Web Service Client
– EGL generated Java under WAS (libraries/services/jsfHandlers)
– EGL generated Java running outside WAS
– EGL generated COBOL running as 3270/CICS Batch programs in CICS
 With remote invocation (CICS ECI or CICS J2C)






No XML parsing
No WSDL processing
Can utilize Channels and Containers
Data can be dynamic length (dynamic arrays, in and out types, etc)
EGL handles the data conversion
Should be better performance (less parsing)
 Can use same generated EGL Service code as used through Web Services
 i.e. no re-generation required
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EGL Services vs Web Services – Controlled via Web Client Bindings
 You can create multiple Web
Client Bindings
 Allows you to create multiple
ways for the services to be
invoked
and
 Allows service client to determine
which protocol to use by
 Referencing name in the
service/interface declaration
using “bindingKey”
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EGL Clients – Calling COBOL/EGL Programs – Option 3B
 Standard EGL Call statement identifies the program
Call “myprog” (parm1, parm2,…);
Parameters:
Can be items and/or records (up to 30)
Passed as values across network
Converted to pointers on mainframe as needed
Data converted on Client side before sending to mainframe
All are treated as in/out parameters (sent both ways)
CICS and IMS…total records can only be 32K unless channel/containers used
Data received using normal “linkage” methods for target program
 EGL communications layer
Provides the interface to various target specific communication protocols
Developer does not need to know anything about:
APIs to make the remote call
How the call is physically implemented
Anything about conversions
The details of making the connection to the remote system are specified in an
EGL “build file” through a linkage options part
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EGL Clients – Calling COBOL/EGL Programs – Option 3B
 Shows
existing
called
programs
in name
space.
 Resulting
code
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RBD/EGL SOA Integration with COBOL – Call Interfaces
z/OS
AIX/Linux/zOS
Client
DB2
CTG Server
WAS web
Services
WAS server
TCP/IP
Call Programx
J2C Config
Tcpipservice port
EGL Generated
Web Service
code
MRO/EXCI
CTG Server
EGL
Generated
ProgramX
Or
Native
COBOL
Programx
CICS
 Web Service is created using EGL wizard based on already created EGL Programx
 No additional coding needed by programmers…just develop called program and generate needed artifact
CTG Server can reside on distributed or z/OS system…not needed on both.
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Linkage Options Build Part Editor – Specifying the linkage option
EGL Build File
1
Program callLink
applies to
1.
Type of callLink
Build Descriptor
must associate the
linkage options to
use (this does not
happen by default!)
So can be different
ones for debugging
vs deployment if
you have different
build descriptors
Properties vary
by type
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Example calling COBOL/CICS from via Java J2C
WebSphere Application Server
1
LAB5SER
Called
Program)
2
3
CICS
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RBD/EGL SOA Integration with COBOL – Which option?
Option 1
Option 2
Option 3:
Description
Create WSDL using RDz
and use EGL to invoke
this WSDL (service)
Use EGL to create CICS
Based web Services
Use Application Server
for Web Service and call
COBOL pgm
Required
Development Tool
Rational Developer
for zSeries with EGL
Rational Business
Developer
Rational Business
Developer
Infrastructure
CICS Web Service
CICS Web Service
WAS (application server)
CICS Transaction
Gateway
Other Factors
Does not require a
separate application
server
Does not require a
separate application
server
Allows use of existing
application server if
already in place
Allows use of “native”
COBOL tooling (RDz) to
build required artifacts
Allows development of
client, service, and
interaction with native
program in single tool
(RBD)
Supports both binary
(CICSJ2C) AND SOAP
based web service from
same generated artifacts
Separate client
technology tool needed
Defined EGL records
can be used.
EGL Records can be
used or created from
COBOL copybooks
(native COBOL)
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Let’s drill down a little more
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Services Considerations
 Services can represent a grouping of business logic:
 Each function in service is a piece of logic related to the group
 E.g. AccountService
– GetAccount
– UpdateAccount
– DeleteAccount
– Etc.
 One function can combine multiple business functions
 More on this in following slides
 Make sure you use exception handling for calls to host programs
 Use UI records (type basicRecords) on calls from RUI Handlers to service
functions. Use different records (if needed) to call back to host programs.
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How would the “call” be used in a service
 Example: Change Amortize to call a program (on CICS) instead of calculating within it.
 Uses 1 record to pass data between RUI handler and service (inputData) (flexible)
 Uses different record to pass data between reused called program and service (usually fixed if from
VAGen
 Can be different depending on needs
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Can also combine multiple calls from one service invocation
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Summary
 Reuse of existing CICS assets is possible
 Several ways to interact/reuse these assets
 Combination of RDz and RBD give:
 Great Flexibility in how the assets are invoked
 Ability to work within existing architectures/infrastructures
 The tools traditional programmers can use to build web services for the enterprise
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Backup
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EGL Web Services – What is generated?
TCPIPSERVICE
SOAP message
Service
Requester
CSOL
CWXN
CICS TS V3.1
CPIH/User Defined Xact
Pipeline
URIMAP
matching
HFS
pipeline
config
WSDL
URIMAP
dynamic
install
PIPELINE
data mapping
Wrapper Pgm
dynamic
install
WSBind
WEBSERVICE
Service Pgm
Generated by EGL
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Defining the CICS Web Services Resources
 Define a TCPIPSERVICE
For Port to listen on for SOAP requests
 Define a PIPELINE
To define the location of the
 WSDL
 WSBIND file (defines mapping of XML to data structure)
 Install the PIPELINE definition and issue CEMT PERFORM PIPELINE
SCAN
This does the following
 Locates the WSBind file
 From the WSBind file, CICS will dynamically create a WEBSERVICE
resource
 CICS will also dynamically create a URIMAP definition
– URIMAP – URL to WebService mapping
 Can define everything individually if preferred
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CICS Pipeline Definition
 Configuration info
Supplied by CICS
 HFS location for CICS
to store resource info
 Location of:
WSBIND
WSDL
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CICS URIMAP

Created by CICS from Pipeline Definition
 URIMAP name
 Generated by CICS
 Relative Path in URL
 Transaction to Start
 Pipeline to use
 Service Name
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CICS WebService Definition
 Created by CICS from Pipeline Definition
 Service name
 Pipeline to use
 URIMAP resource
definition
 Program to run
 Wsbind/WSDL file
location for data
mapping
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