steve graham [email protected]
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WS-ResourceFramework Technical Overview. OASIS Tutorial Sunday, April 26th, 2004. Steve Graham [email protected]. Agenda. Introduction, Motivation and Core concepts Overview of the WS-ResourceFramework specifications Resource Properties Resource Lifetime ServiceGroup BaseFaults - PowerPoint PPT PresentationTRANSCRIPT
Steve Graham [email protected]
WS-ResourceFrameworkTechnical Overview
OASIS Tutorial Sunday, April 26th, 2004
© 2004 IBM Corporation 2
Agenda
Introduction, Motivation and Core concepts
Overview of the WS-ResourceFramework specifications
• Resource Properties• Resource Lifetime• ServiceGroup• BaseFaults
Demo
WS-Notification discussion
Conclusions
© 2004 IBM Corporation 3
Motivation
Stateful entities exist in most systems
• Data in a purchase order• Current usage agreement for resources • Metrics associated with work load on a server
Hitherto: no standard way to deal with state in Web services context
• Each system does it in “idiosyncratic way”• Integration impediment
Goal:
• Formalize a mechanism to represent “state” in Web services• In order to help unify Grid computing, Systems management
and e-business computing
© 2004 IBM Corporation 4
Scope of WS-ResourceFramework
How to represent state in a Web services context
How is state referenced and “identified” in Web services
How is state modeled in XML and WSDL
How is state accessed through Web services
How to reason about lifetime of state
How to aggregate/collect stateful resources
How to reason about fault messages
© 2004 IBM Corporation 5
Overview of Scenario
At several points we will use examples from the systems management domain
In particular, imagine applications that use Web services to view/manipulate operating systems and processes that run on them
processProcessPropertiescreationClassNamecreationDatecsCreationClassNamecsNameexecutionStatehandlekernelModeTimenameosCreationClassNameosNamepriorityterminationDateworkingSetSizeCurrentTimeTerminationTime
GetResourceProperty()QueryResourceProperties()Destroy()
OperatingSystemOSPropertiescreationClassNamecsCreationClassNamecsNamefreePhysical MemoryfreeVirtualMemorynamenumberOfProcessesnumberOfUsersoperationalStatusosTypetotalSwapSpaceSizetotalVirtualMemorytotalVisibleMemoryversionCurrentTimeTerminationTime
findAllOperatingSystems()findHostedPorcesses()GetResourceProperty()QueryResourceProperties()Destroy()
© 2004 IBM Corporation 6
What is a Web Service ?
An operation execution component made available at an endpoint address
• A service is defined in terms of the operations it implements
– An operation is defined in terms of a message exchange
• The supported set of messages exchanges (operations) implemented by a service may be described as a WSDL portType
• The Web service itself is typically stateless Accessible through use of a WS-Addressing Endpoint
Reference
Lifecycle of a Web service typically described in terms of “deployment”
© 2004 IBM Corporation 7
What do we mean by Stateful Resource ?
A specific set of state data expressible as an XML document;
Has a well-defined identity and lifecycle; and Known to, and acted upon, by one or more Web
services. Many possible implementations
• Files, Database tables, EJB Entities, XML documents, Composed from multiple data sources, etc.
Lifecycle expressed in terms of resource creation and destruction• Multiple independent instances may be created and destroyed• Identity is assigned at creation time
© 2004 IBM Corporation 8
WS-Addressing: Referencing Web services Standardizes the representation of the address of a Web service
deployed at a given network endpoint A WS-Addressing endpoint reference is an XML serialization of a
network-wide pointer to a Web service EPRs can be used to pass services to other services by reference Dynamic generation and customization of service endpoint descriptions Identification and description of specific service instances that are
created as the result of stateful interactions An EPR contains:
• Service address (wsa:Address)• Metadata associated with the Web service such as service description
information (WSDL)• Policy information related to the use of the service• Reference properties, which can be used to identify specific stateful
resource instances associated with the Web service at the endpoint address (wsa: ReferenceProperties)
© 2004 IBM Corporation 9
Inte
rface
WebService
message
message
address
Endpoint Reference
Run-time environment
Invoking a Web service using WS-Addressing
© 2004 IBM Corporation 10
WS-Resource
WS-Resource: Web service + associated resource• In other words:
– A resource with an associated Web service A WS-Resource has:
• Identity: Can be uniquely identified/referenced• Lifetime: Often created & destroyed by clients• State: Can be projected as an XML document • Type: Its Web service interface
An EPR “points to” a WS-Resource• WS-Resource Qualified Endpoint Reference• Implied Resource Pattern
© 2004 IBM Corporation 11
Contents of EndpointReference
Service
Requestor
A
B
C
1
5
4
2
<wsa:EndpointReference> <wsa:Address> http://someOrg.com/process </wsa:Address> <wsa:ReferenceProperties> <tns:process> C </tns:process> </wsa:ReferenceProperties> </wsa:EndpointReference> 3
© 2004 IBM Corporation 12
context
Inte
rface
WebService
messageid
message
id
address
resource
Run-time environment
Endpoint Reference
Using an EPR to Access a WS-Resource
© 2004 IBM Corporation 13
context
Inte
rface
WebService
messageid
message
id
address
resource
resource
Endpoint ReferenceEndpoint Reference
Different WS-Resources, Different EPRs
Run-time environment
© 2004 IBM Corporation 14
The WS-Resource Qualified Endpoint Reference
Service
Requestor
<soap:Envelope> <soap:Header> <tns:process> C </tns:process> </soap:Header> <soap:Body> … some message </soap:Body> </soap:Envelope> … </soap:Envelope>
A
B
C
3
2
1 C
4
An endpoint reference containing a WS-Resource identifier is a WS-Resource-qualified endpoint reference.
© 2004 IBM Corporation 15
WS-Resource Identifier
The WS-Resource identifier is a “lookup key” the WS-Resource to be used in the execution of the request message
• The set of reference properties
The content of the WS-Resource identifier is opaque to the service requestor
• The service requestor’s applications should not examine or attempt to interpret the contents of the WS-Resource identifier
• The WS-Resource identifier is meaningful only to the Web service
From the point of view of the service requestor:
• EPR is a pointer to the Web service + WS-Resource • In other words, the EPR represents a pointer to a WS-Resource
accessible through a Web service
© 2004 IBM Corporation 16
Inte
rface
WebService
message
message
address
Endpoint Reference
resource
Endpoint Reference
address
id
Creating/Locating a WS-Resource
Run-time environment
© 2004 IBM Corporation 17
WS-Resource Relationship Cardinality
A Web service can execute message exchanges against zero or more WS-Resources of a given type
One Stateful resource can be “associated” with multiple Web services
• Different interfaces, or same interface for redundancy At the type level, a WSDL 1.1 portType, defining the interface to a Web
service, can be associated with at most one “kind” or “type” of WS-Resource
One “kind” or “type” of WS-Resource can be associated with many WSDL 1.1 portTypes
A
CWS1
B
WS2
© 2004 IBM Corporation 18
WS-Resource Composability
WS-RF is part of the Web services set of technologies
Key to Web services is the notion of composability• Web services is a (growing) set of small(ish) specs• Systems are built by “composing” these specs in
various ways• Eg
– WS-RF DOES NOT define a security model» Use WS-Security
– WS-RF DOES NOT define a reliable messaging model» Use WS-ReliableMessaging
– WS-RF DOES NOT define a transactions model» Use WS-AtomicTransaction, etc.
– ETC.
© 2004 IBM Corporation 19
Agenda
Introduction, Motivation and Core concepts
Overview of the WS-ResourceFramework specifications
• Resource Properties• Resource Lifetime• ServiceGroup• BaseFaults
Demo
WS-Notification discussion
Conclusions
© 2004 IBM Corporation 20
WS-ResourceFramework
A family of documents and specifications• CA, Fujitsu, Globus, HP, IBM
White papers:• Modeling Stateful Resources with Web services
– “State Paper”
• WS-Resource Framework overview• OGSI -> WS-RF
Specifications• WS-ResourceProperties• WS-ResourceLifetime• WS-ServiceGroup• WS-BaseFaults
WS-
Serv
ice
Gro
ups
WS-
Not
ifica
tion
Modeling Stateful
Resources with Web Services
WS-B
ase Faults
WS-ResourceProperties W
S-Resource
Lifetime
© 2004 IBM Corporation 21
Status of WS-ResourceFramework
Specifications announced on January 20, 2004• WS-ResourceProperties, WS-ResourceLifetime, State Paper• http://www-106.ibm.com/developerworks/webservices/library/ws-resource/
Co-author feedback session on February 16
Public feedback session February 23
Specifications updated March 5
• Added the WS-RF overview paper and OGSI->WSRF paper OASIS Technical Committee call for participation March 9
WS-BaseFaults and WS-ServiceGroup on March 31
• Public feedback April 16 Interoperability “fest” April 20
First meeting of OASIS TC April 28
© 2004 IBM Corporation 22
Agenda
Introduction, Motivation and Core concepts
Overview of the WS-ResourceFramework specifications
• Resource Properties• Resource Lifetime• ServiceGroup• BaseFaults
Demo
WS-Notification discussion
Conclusions
© 2004 IBM Corporation 23
Defines:• How to use XML schema to model elements of
resource state • How to associate resource’s state model with
WSDL portType• Standard operations for getting, setting, querying, • Standard mechanism to use WS-Notification to
subscribe for state value changes
Why:• Basis for standard resource inspection, monitoring
and state management
WS-ResourceProperties
© 2004 IBM Corporation 24
How is State Modeled?
XML of course
• Instance document associated with a WS-Resource• The WS-Resource’s “Resource Properties document”
Elements of state are modeled as child elements of the root <process:ProcessProperties>
<process:csName> xclock </process:csName> <process:executionState> Suspended Ready </ …> <process:handle> 2824 </process:handle>… <wsrl:CurrentTime> 23 Apr 2004 19:45:29 GMT </ … > <wsrl:TerminationTime xsi:nil=“true” /></process:ProcessProperties>
XSD:ref is used to “combine” Resource Properties from various definitions
© 2004 IBM Corporation 25
<!-- RPDoc declaration for Process --><xsd:element name="ProcessProperties" type="process:ProcessPropertiesType"/>
<xsd:complexType name="ProcessPropertiesType">
<xsd:sequence>
<xsd:element ref="process:Name"/>
<xsd:element ref="process:CSName"/>
<xsd:element ref="process:OSName"/>
<xsd:element ref="process:Handle"/>
<xsd:element ref="process:Priority"/>
<xsd:element ref="process:ExecutionState"/>
<xsd:element ref="process:CreationDate"/>
<xsd:element ref="process:TerminationDate"/>
<xsd:element ref="process:KernelModeTime"/>
<xsd:element ref="process:WorkingSetSize"/>
<xsd:element maxOccurs="1" minOccurs="1" ref="process:resourceID"/>
<xsd:element maxOccurs="1" minOccurs="1" ref="wsrl:CurrentTime"/>
<xsd:element maxOccurs="1" minOccurs="1" ref="wsrl:TerminationTime"/>
…
© 2004 IBM Corporation 26
ResourceProperties Document and WSDL
ResourceProperties document is associated with the wsdl portType:
<wsdl:portType name="Process"
wsrp:ResourceProperties="process:ProcessProperties">
<wsdl:operation name="findHostingOperatingSystem"> …
<wsdl:operation name="GetResourceProperty"> …
<wsdl:operation name="QueryResourceProperties"> …
<wsdl:operation name="Destroy"> …
</wsdl:portType>
@ResourceProperties provides meta-data to assist developers and value-add tooling
© 2004 IBM Corporation 27
WS-ResourceProperties Operations
GetResourceProperty
• Simple single resource property element getter• Required• <wsrp:GetResourceProperty> process:handle</wsrp:GetResourceProperty>
• <wsrp:GetResourcePropertyResponse> <process:handle>1577 </process:handle></wsrp:GetResourceProperty>
<wsrp:GetResourceProperty> QName </wsrp:GetResourceProperty>
© 2004 IBM Corporation 28
WS-ResourceProperties Operations
Get Multiple Resource Properties
• More sophisticated multiple property value retrieval• Optional • <wsrp:GetMultipleResourceProperties> <wsrp:ResourceProperty>process:handle </ …> <wsrp:ResourceProperty>process:executionState <wsrp:ResourceProperty>process:csName </…></wsrp:GetMultipleResourceProperties>
• <wsrp:GetMultipleResourcePropertiesResponse> <process:handle>2824 </process:handle> <process:executionState>Suspended Ready </… <process:csName> xclock </process:csName></wsrp:GetMultipleResourcePropertiesResponse>
<wsrp:GetMultipleResourceProperties> <wsrp:ResourceProperty>QName </wsrp:ResourceProperty>* </wsrp:GetMultipleResourceProperties>
© 2004 IBM Corporation 29
WS-ResourceProperties Operations
QueryResourceProperties
• Execute an expression against the resource properties document
• Optional• QueryExpression defines dialect by URI
– XPath 1.0, 2.0– XQuery– SQL– StevesAmazingQueryExpression
<wsrp:QueryResourceProperties> <wsrp:QueryExpression dialect=”URI”> xsd:any </wsrp:QueryExpression> </wsrp:QueryResourceProperties>
© 2004 IBM Corporation 30
WS-ResourceProperties
Set Resource Properties
• Modify a resource property document• optional
<wsrp:SetResourceProperties> { <wsrp:Insert > xsd:any* </wsrp:Insert> |
<wsrp:Update > xsd:any * </wsrp:Update> |
<wsrp:Delete ResourceProperty=”QName” /> }+ </wsrp:SetResourceProperties>
© 2004 IBM Corporation 31
Agenda
Introduction, Motivation and Core concepts
Overview of the WS-ResourceFramework specifications
• Resource Properties• Resource Lifetime• ServiceGroup• BaseFaults
Demo
WS-Notification discussion
Conclusions
© 2004 IBM Corporation 32
WS-ResourceLifetime Defines:
• Immediate, synchronous destruction operation• Time-based, scheduled destruction operation
– “Soft-state” or “leased” lifetime management– Termination time no required to monotonically increase
• Resource properties:– CurrentTime: Can be used to determine clock skew– TerminationTime: Current scheduled termination time
• Notification of resource termination Why:
• Define clear means by which WS-Resources can be destroyed
© 2004 IBM Corporation 33
WS-ResourceLifetime
Immediate Destruction
Scheduled Destruction
Resource Properties
• Current Time• Termination Time
<wsrl:Destroy />
<wsrl:SetTermination> <wsrl:RequestedTerminationTime> xsd:dateTime </wsrl:RequestedTerminationTime> </wsrl:SetTerminationTime>
© 2004 IBM Corporation 34
Agenda
Introduction, Motivation and Core concepts
Overview of the WS-ResourceFramework specifications
• Resource Properties• Resource Lifetime• ServiceGroup• BaseFaults
Demo
WS-Notification discussion
Conclusions
© 2004 IBM Corporation 35
WS-ServiceGroup Defines:
• Web service interfaces for representing and managing a by-reference collection of EPRs to Web services or WS-Resources
• Each entry is member EPR + associated content– WS-RP used for representing the entries– Can have rules to membership and content– Members may be homogenous or heterogenous, depending on the
purpose and membership rules of the group• Has a registration interface for adding entries
– Follows the WS-Resource factory pattern– The entry is represented as a WS-Resource
• WS-RL used for removing entries Why:
• Myriad of reasons for groups: E.g. Registries, collective operations, federated services, etc.
© 2004 IBM Corporation 36
ServiceGroup Model
© 2004 IBM Corporation 37
ServiceGroup Interfaces ServiceGroup
• A collection of Web services and the information that pertains to them.
• Purpose is application domain specific ServiceGroupEntry
• A Web service that represents the member and associated content
ServiceGroupRegistration
• Message exchange for adding new members to a ServiceGroup• Membership may occur in other ways
Member
• (any Web service)
© 2004 IBM Corporation 38
ServiceGroup Characteristics When a ServiceGroup is destroyed, all of the
ServiceGroupEntries are also recommended to be destroyed. However, the members are not affected.
Once a ServiceGroup is destroyed, no assumptions can be made about either the existence of the ServiceGroupEntry or it’s contents.
A member may belong to several ServiceGroups.
A member may belong to the same ServiceGroup more then once.
The member of a ServiceGroup may implement message exchanges from various interfaces.
If a member is destroyed, the ServiceGroup may destroy the corresponding ServiceGroupEntry(s).
© 2004 IBM Corporation 39
ServiceGroup Resource Properties MembershipContentRule
• These elements specify the constraints on membership of the service group
Entry
• These elements represent the projection of the aggregation of the resource property documents of the ServiceGroup’s entry resources
© 2004 IBM Corporation 40
Agenda
Introduction, Motivation and Core concepts
Overview of the WS-ResourceFramework specifications
• Resource Properties• Resource Lifetime• ServiceGroup• BaseFaults
Demo
WS-Notification discussion
Conclusions
© 2004 IBM Corporation 41
WS-BaseFaults Defines
• Set of “common” properties of a fault• Convention for specializing “common” fault• How “common” fault type is used in WSDL
Why?
• Increases the likelihood that service requestors to automatically (without human intervention) understand and/or adapt to faults requires interface designers to define rich, structured fault messages
• Standard fault messages encourage tooling that can assist interface designers, service implementers, and client implementers
© 2004 IBM Corporation 42
BaseFault Element<BaseFault> <-- type=BaseFaultType -->
<Timestamp>xsd:dateTime</Timestamp>
<OriginatorReference>
wsa:EndpointReferenceType
</OriginatorReference> ?
<ErrorCode dialect="anyURI">xsd:string</ErrorCode> ?
<Description>xsd:string</Description> *
<FaultCause>wsbf:BaseFault</FaultCause> *
</BaseFault>
© 2004 IBM Corporation 43
BaseFaultType Information Items Timestamp (required)
• Time at which the fault occurred OriginatorReference (optional)
• WS-Addressing EndpointReference of the WS that generated the fault
• Can omit if it is clearly implied• Useful particularly with FaultCause
ErrorCode (optional)• String error code for supporting legacy fault reporting systems• @dialect: URI specifying context of string
Description (0..unbounded)• Plain language description(s) of the fault• Use with xsi:lang
FaultCause (0..unbounded)• BaseFault element(s) that describes the underlying cause of
this fault.
© 2004 IBM Corporation 44
Using BaseFaultType For each distinct fault on WSDL operation
1. Define XSD complexType that extends BaseFaultType• Represents the fault’s distinct type• May not define any additional fields
2. Define XSD element with this extended fault type3. Define WSDL message using this fault element4. Define WSDL operation fault element using this
messag
© 2004 IBM Corporation 45
Binding to SOAP
WS-BaseFaults only specifies what is done at WSDL 1.1 abstract interface (portType) level
• Intended for defining service/application faults Binding a fault message to SOAP is the purview of
a WSDL binding definition
• Use standard WSDL 1.1 SOAP 1.1 binding Issue: Some redundancy between WS-BaseFault
information and SOAP 1.2 faults
• May want some changes to WS-BaseFaults for WSDL 2.0 and its SOAP 1.2 binding
© 2004 IBM Corporation 46
Agenda
Introduction, Motivation and Core concepts
Overview of the WS-ResourceFramework specifications
• Resource Properties• Resource Lifetime• ServiceGroup• BaseFaults
Demo
WS-Notification discussion
Conclusions
© 2004 IBM Corporation 47
The Demo Services and Scenarios
Ability to find known operating systems represented as services. Ability to find all processes hosted on a given operating system
represented as services. Monitor and introspect both operating system and process state via
resources properties. Destroy (terminate) a selected process resource via its services
interface.
Operating System
Service
Process
Service
Pegasus CIMOMHa
nd
lers
Process
OS
WebSphere
© 2004 IBM Corporation 48
Demo Details
Pegasus CIMOM
ProcessOS
Ha
nd
lers
Operating System
Service
Process
Service
WebSphere
Client
Proxies
EPRHelpers
Ha
nd
lersClient
UI
Client Container
Web Services
Servlets
Stateless
Session
Beans
EJB Container
EPRHelpers
Ha
nd
lers
Web Container
Entity
Beans
© 2004 IBM Corporation 49
Demo
WSAD IE 5.1 on Windows XP• Integration Test Server 5.1
– WBI Runtime
Pegasus 2.3.1 on RH 9.0
• sblim base providers
© 2004 IBM Corporation 50
Agenda
Introduction, Motivation and Core concepts
Overview of the WS-ResourceFramework specifications
• Resource Properties• Resource Lifetime• ServiceGroup• BaseFaults
Demo
WS-Notification discussion
Conclusions
© 2004 IBM Corporation 51
WS-Notification WS-Notification
• Brings enterprise quality publish and subscribe messaging to Web services
– Loosely coupled, asynchronous messaging in a Web services context
• WS Notification exploits WS Resource framework and other Web services technologies
• Direct and Brokered notification• Topics and Topic Spaces• More on subscribe• Use of WS-Notification in WS-RF
© 2004 IBM Corporation 52
WS-Notification Family of Documents
WS-Notification is a family of documents:• Publish-Subscribe for Web services
– Whitepaper describing roles, concepts, terms, etc.
• Base Notification– Basic interfaces: Producer, Consumer, Subscription
• Topics– Topics and TopicSpaces model in XML– Topic Expression Dialects
• Brokered Notification– Mechanisms of Publish and the Broker role
Authored by:• CA, Fujitsu, Globus, HP, IBM
+ Akamai, SAP, Sonic, Tibco
© 2004 IBM Corporation 53
Status of WS-Notification
Specification announced on January 20, 2004• http://www-106.ibm.com/developerworks/webservices/library/ws-notification/
Co-author feedback session on February 17
Public feedback session February 24
Specifications updated March 5
• Factored into 4 documents (see previous slide) OASIS Technical Committee call for participation
March 9
Interoperability “fest” April 21
First meeting of OASIS TC April 29
© 2004 IBM Corporation 54
Consumer
Producer
Subscriber
WS-Notification: Base Notification
subscribe
subscribe
S
notify
EPR
Defines the Basis for the familyDirect notification: Three primary rolesSubscriber deals directly with the
producer of the Notifications• indicates interest in a particular
“Topic” by issuing a “subscribe” request
An EPR to the subscription is returned
Producer is responsible fordetecting situation and creating the notification
Subscriptions that matchreceive the notification
© 2004 IBM Corporation 55
Similar roles as in direct, adding ‘Broker’ Role
• Broker (intermediary) permits decoupling Publisher and Subscriber
Subscriber indicates interest in a particular “Topic” by issuing a “subscribe” request
“Subscriptions” are WS-Resources
• Various subscriptions are possible New role: Publisher
• need NOT be a Web Service Publisher detects situation:
• Publishes the Notification to a broker
Broker responsible for disseminating notifications
• examines current subscriptions for match Brokers may provide “value add”
• “Transform” or “interpret” topics• Federate to provide scalability
Broker
Subscriber
WS-Notification: Brokered Notification
Publisher
subscribe
subscribe
S S S
notify
notify
notify
notify
© 2004 IBM Corporation 56
WS-Notification
More on Subscribe Request
Returns EPR to a Subscription WS-Resource
<wsnt:Subscribe> <wsnt:ConsumerReference>EPR </wsnt: ConsumerReference> <wsnt:TopicExpression dialect=“URI”/> <wsnt:UseNotify> xsd:boolean </wsnt:UseNotify>? <wsnt:Precondition> wsrp:QueryExpression </Precondition>? <wsnt:Selector> wsrp:QueryExpression </wsnt:Selector>? <wsnt:SubscriptionPolicy> any </wsnt:SubscriptionPolicy>? <wsnt:InitialTerminationTime> xsd:dateTime </wsnt:InitialTerminationTime>?</wsnt: Subscribe>
© 2004 IBM Corporation 57
WS-Notification
Topics and Topic Spaces
• Meta-data to help– Organize Notifications– Tell the Subscriber what to subscribe to<?xml version="1.0" encoding="UTF-8"?>
<wstop:topicSpace name="TopicSpaceExample1" targetNamespace="http://example.org/topicSpace/example1" … > <wstop:topic name="t1"> <wstop:topic name="t2" messageTypes=“tns:m1 tns:m2"/> <wstop:topic name="t3" messageTypes=“tns:m3"/> </wstop:topic> <wstop:topic name="t4"> <wstop:topic name="t5" messageTypes=“tns:m3"/> <wstop:topic name="t6" aliasRef="tns:t1/t3"/> </wstop:topic></wstop:topicSpace>
© 2004 IBM Corporation 58
WS-ResourceProperties
Subscription for Value Change Rules for mapping resource properties to Topics
• QName of resource property corresponds QName of Topic To subscribe to changes in process:ExecutionState:
Suggested format of value change message
<wsnt:Subscribe> <wsnt:ConsumerReference>… <wsnt:TopicExpression dialect=“uri”> process:executionState <wsnt:TopicExpression> …</wsnt: Subscribe>
© 2004 IBM Corporation 59
Shameless Plug for My (upcoming) Book
© 2004 IBM Corporation 60
Credits
Most of the material is the result of collaborative effort from:• Steve Graham, Jeff Frey, Jay Unger, Steve Tuecke
and Tom Maguire. BaseFaults section derived from material courtesy
of Steve Tuecke ServiceGroup section derived from material
courtesy of Tom Maguire Demo and scenario derived from material courtesy
of:• Mike Williams, Revathi Subramanian, JaiPaul
Antony, Bob Hansen