Technical Relationship between WSMX & Globus Toolkit Matthew Moran, Kashif Iqbal
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Transcript of Technical Relationship between WSMX & Globus Toolkit Matthew Moran, Kashif Iqbal
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Technical Relationship betweenWSMX & Globus Toolkit
Matthew Moran, Kashif Iqbal
Digital Enterprise Research Institute, Galway{Matthew.moran, Kashif.Iqbal}@deri.org
14 Jan 2005
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Agenda
• Setting the scene– Introduction & motivation– Distributed computing– Framework for comparison
• Semantic Web Services– Rationale and research focus– WSMX
• Grid Computing– Rationale and research focus– Globus Toolkit
• WSMX and Globus Toolkit• Conclusions
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Introduction
• Two distinct research communities– Semantic Web Services– Grid Computing– Domain of both is distributed computing systems
• General – do Grid and SWS fit together?– SWS on Grid – or – Grid on SWS
• Specific – WSMX and Globus Toolkit– What is the relationship?– Complementary or competing architectures?– If complementary, how do they fit?
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Distributed Computing Systems
• Motivation– The need for system and data integration across
heterogeneous and autonomous systems
• Many previous efforts (more that are not listed)– TP Monitors – CICS,
• Excellent for transaction processing; tight code coupling– Client Server and RPC
• More flexible, still tight code coupling– Corba and DCOM
• Object oriented rather than business process or document integration
• UML a suitable modelling paradigm– Web Services
• Great potential but where are the semantics?• BPM a suitable modelling paradigm
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Distributed Computing Systems
• Functional requirements– Synchronous and asynchronous message exchange– Heterogeneous and autonomous system integration– Publish and deploy services– Discover and invoke services – Data and process mediation
• Non functional requirements– Transparency– Availability– Maximise resource usage– Throughput– Security– Transaction processing – Reliability
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Framework for Comparison
• Agree on terminology– Service– Resource– Publish and deploy– Discovery– Service level agreements (SLA)– Negotiation
• Functional and non-func requirements• Architecture • Messaging• Domain of interest
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Semantic Web Services
• What is the application area for SWS?– Application and process integration– Inter- and intra- business– Focus on business documents and processes– WS not an artificial homogeneity– SWS addresses service discovery, composition
• Problems with WS do they address?– Absence of formal semantics
• Focus for the SWS research community?– Description, discovery, composition, invocation,
mediation
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WSMX
• Mission – To develop an execution environment for dynamic
discovery, selection, mediation and invocation of Semantic Web Services
– To be the middleware for Semantic Web Services
• Conceptual model provided by WSMO– Ontology, Goal, Service, Mediator– Describe concepts from perspectives of both the
requester and provider
• Multiple execution semantics possible– For example, discovery or mediation only.
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WSM* Family
WSMO: Conceptual Model
WSML: Language
WSMX: Architecture & Ref. Implementation
SemanticWeb Services
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WSM* Family
WSMO: Conceptual Model
WSML: Language
WSMX: Architecture & Ref. Implementation
SemanticWeb Services
Ontology
Syntax & semantics
CompositionEvent-basedFramework
Discovery
Invocation Mediation
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WSMX
• Available functionality– Backend adaptors– Accept and parse WSML messages– Store services, goals, mediators, ontologies– Simple discovery– Data mediation– Simple invocation
• Functionality in development– Choreography component– WSMO Editor
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Grid Overview
• What is the application area for Grid?– Traditionally: computational grids– Potential: for business processes and SOA– IBM dream of computing on demand
• WS and Grid– Globus toolkit takes advantage of widely accepted
WS standards to implements its services– WS Addressing to make stateful services
• Research community focus for Grid?– Resource management, security, high throughput,
managed availability amongst others
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What is a Grid? Evolving definition …
• ’98: hardware and software infrastructure that provides dependable, consistent and pervasive access to high-end computational capabilities
• ’00: coordinated resource sharing and problem solving in dynamic, multi-institutional organizations
• ’02 checklist. A grid:– Coordinates resources that are not subject to
centralized control, …– … using standard, open, general-purpose
protocols and interfaces, …– … to deliver non-trivial qualities of service.
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What Kinds of Applications?
• Computation intensive– Interactive simulation (climate modeling)– Very large-scale simulation and analysis (galaxy formation,
gravity waves, battlefield simulation)– Engineering (parameter studies, linked component models)
• Data intensive– Experimental data analysis (high-energy physics)– Image and sensor analysis (astronomy, climate study, etc.)
• Distributed collaboration– Online instrumentation (microscopes, x-ray devices, etc.)– Remote visualization (biology)– Engineering (large-scale structural testing, chemical
engineering)
• Business grids
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What Types of Problems?
• Security: – Hard to keep track of authentication data across institutions
• Monitoring/discovery: – Hard to monitor system and app. status across institutions
• Accessing computing/processing power– Too many ways to submit jobs
• Moving data– Too many ways to store & access files and data
• Managing data– Too many ways to keep track of data
• Managing systems• System packaging/distribution
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Grid and Web Services Convergence
The definition of WSRF means that the Grid and Web services communities can move forward on a common base.
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What Is the Globus Toolkit?
• A Grid development environment– Develop new OGSA-compliant Web Services– Develop applications using Java or C/C++ Grid APIs– Secure applications using basic security mechanisms
• A set of basic Grid services– Job submission/management– File transfer (individual, queued)– Database access– Data management (replication, metadata)– Monitoring/Indexing system information
• Tools and Examples• The prerequisites for many Grid community tools
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Globus Toolkit and Web Services
• Web services have major advantages for Grids– Standard interface definition– Good commercial tooling (eventually)
• However, not a silver bullet or complete solution …• Globus Alliance working to advance specs …
– OGSI/WSRF, OGSA-DAI, WS-Agreement, etc.– WSDL 2.0, WSDM, WS-Security, etc.
• … and implementation– Implementations of low-level specifications– WS-based interface to existing services– New WS-based services
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Components in Globus Toolkit 3.2
GSI
WS-Security
CAS(OGSI)
SimpleCA
Data Managemen
tSecurity
WSCore
Resource Managemen
t
Information Services
RFT(OGSI)
RLS
OGSI-DAI
WU GridFTP
XIO
JAVAWS Core(OGSI)
OGSI C Bindings
MDS2
WS-Index(OGSI)
Pre-WSGRAM
WS GRAM(OGSI)
OGSI Python Bindings
(contributed)
pyGlobus(contributed)
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Deployment View
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Theory -> Practice
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GT3
Security Infrastructure (GSI)
OGSI/WSRF
MJFS
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Network
RRR
A
ServiceLevel
Bringing it All TogetherScenario: Resource management & scheduling
Storage
RRRIBM
IBM
Blades
RRR
Notification
GridScheduler
WS-Resource used to “model” physical
processor resources
WS-Resource Properties “project” processor status (like utilization)
Local processor manageris “front-ended” with A Web service interface
Other kinds of resources are also“modeled” as WS-Resources
JJ
J
WS-Notification can be used to “inform” the
scheduler when processor utilization
changes
Grid “Jobs” and “tasks” are also modeled using
WS-Resources and Resource Properties
Grid Scheduleris a
Web Service
Service Level Agreement
is modeled as a WS-Resource
Lifetime of SLA Resource tied to the duration
of the agreement
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WSMX and Globus – Common
• Both distributed computing systems• Both use WS standards as foundation technology
– WSDL– SOAP
• Both provide approaches to B2B integration• Despite current differences in focus, both face the
same kind of problems– Semantics – service discovery– Service availability management– Security– Service Level Agreements (SLA)
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WSMX and Globus – Differences
• Different research communities• Different functionalities offered right now• WSMX provides SOA event driven framework• Globus is a loose toolkit• WSMX addresses service description, discovery,
invocation and mediation at data and process• Globus provides resource life-cycle mgt, soft-state,
real-time service information, service notification interface, security including delegated security, access to system data and files
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WSM* Family
WSMO: Conceptual Model
WSML: Language
WSMX: Architecture & Ref. Implementation
SemanticWeb Services
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WSM* Family
WSMO: Conceptual Model
WSML: Language
WSMX: Architecture & Ref. Implementation
SemanticWeb Services
Ontology
Syntax & semantics
CompositionEvent-basedFramework
Discovery
Invocation Mediation
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WSM* and Globus
WSMO: Conceptual Model
WSML: Language
WSMX: Architecture & Ref. Implementation
SemanticWeb Services
Globus
Ontologies
Syntax
CompositionEvent-basedFramework
Discovery
Invocation Mediation
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WSM* and Globus
WSMO: Conceptual Model
WSML: Language
WSMX: Architecture & Ref. Implementation
SemanticWeb Services
Globus
Ontologies
Syntax
MonitoringSoft-state
mgt
WSRF
WS-Addressing
CompositionEvent-basedFramework
Discovery
Invocation MediationResource
MgtSecurity
ServiceFactory
SLA Mgt
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WSMX and Globus – Do the fit?
• Complementary or competitive– complementary
• WSMX in Globus – or – Globus in WSMX– Neither – they address different functionalities– GT3 is implemented as a set of WS– For GT3 services to be available to WSMX, they
need to be described in terms of WSMO– A GT3 client could choose to use WSMX as its
discovery and execution engine while using the GT3 core services for resource mgt, security etc.
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Convergence ofGrid and Web Services
Grid
Web
WSRF
Started far apart in apps & tech
OGSI
GT2GT1
HTTPWSDL,
WS-*
WSDL 2,
WSDM
Have beenconverging
• The definition of WSRF means that Grid and Web communities can move forward on a common base• Support from major WS vendors, especially in management space: e.g. HP, IBM
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Scenarios
• Stock exchange statistics example• Scenario 1– WSMX only for discovery
• Scenario 2– WSMX for discovery choreography and invocation
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Conclusion
• WSMX is an execution environment for SWS has a particular focus– Description, discovery, mediation, invocation, etc.
• Globus is a toolkit providing various services that have immediate relevance for computational grids but growing relevance for business process integration
• Both technologies are based on WS standards facilitates interoperability
• Little overlap between service offered