1. OGSA Hauptseminar: Data Grid Thema 2: Open Grid Service Architecture
...Everything is service...
Hauptseminar: Data Grid
Thema 2: Open Grid Service Architecture
Vorträger: Lu xin

2. OGSA History OGSA Announced at GGF4 (’02/2) Work Group created (’02/9)
6 interim F2F meetings
OGSA Usecase document at GGF10 (’04/3)
Declared as GGF’s flagship architecture at GGF10 (’04/3)
OGSA document at GGF11 (’04/6)
First version as informational document
Companion OGSA Glossary document 2

3. OGSA
What is OGSA?
Foster:
Open service-oriented architecture based on Web services for addressing Grid scenarios
Component-oriented architecture
Interchangeable components
Meta OS functionalities
Distributed and heterogeneous environment
A rendering of these functions, based on
Web service architecture and specifications 3

4. GOAL OGSA Realization of the modern computing environment:
Manage resources across distributed heterogeneous platforms.
Deliver seamless quality of service (QoS).
Provide a common base for autonomic management solutions.
Define open, published interfaces.
Exploit industry standard integration technologies.
Realization of the modern computing environment:
Discovered
Allocated
Accessed
Monitored
Accounted for
Billed for
etc…
The components can be in general managed as a single virtual system 4

5. Concept & Consensus OGSA
Everything is represented as a Grid service. All components of the environment are virtualized.
keyword:
Grid Service
“ Open Grid Service Architecture suppose a concept called Grid Service, it puts heavy emphasis on the concept of “services”. ”
Interfaces
Service Data
“ The emergence of OGSA represent s a consensus on the standardization of resource accessing interfaces as grid services”
keyword:
Standardization 5

6. OGSA
OGSA Architecture 6

7. Service Oriented Architecture
OGSA
OGSA Architecture
Layers:
Grid applications
OGSA architected services
Web services
+the OGSI extensions that define grid services
Discovery >> UDDI (Universal Description, Discovery & Integration)
Description >> WSDL (Web Services Description Language), XML..
Invocation >> SOAP (Simple Object Access Protocol)
Transport >> HTTP (HyperText Transfer Protocol)
Resources
physical resources and logical resources
Service
Registry
Provider
Requestor
Find
Publish
Bind
WDSL
UDDI
WS-Inspector
SOAP
Service Oriented Architecture 7

8. overview OGSA What is happened here?? Just like web service?? 8
Physical storage
Virtual storage
Client X
Virtual
Storage
Factory
Client X
Client X 8

9. Grid Service OGSA Stateful and potentially transient services
Useful for the Clain Operations(realy?)
Typical Web Service
Grid Service
based on Web Service 9

10. Grid Service OGSA Service Data Service Data Set Lifecycle management
Service Statedata(opertaion result, runtime infos..)
Service Metadata(introspection )
Service Data Element (SDE)
Name
Type (XML type)
Extensibility attributes
Lifetime declarations
Application-specific
Extensibility elements
Service data value
Service Data Set
A set of SDEs
Each Grid Service must have exactly one service Data Set
Accessible in two ways:
FindServiceData
Notification
Lifecycle management
Instance can be created and destoried at any time 10

11. Grid Service Example OGSA Service Data in WSDL 11
<wsdl:definitions xmlns=“…” targetNamespace=“…”>
<gwsdl:portType name=“StorageService”
extends=“gsdl:GridService”>
<wsdl:operation name=getFile> …
</wsdl:operation>
<sdf:serviceData name=“capacity” type=“xsd:integer”/>
<sdf:serviceData name=“lifeTime” type=“xsd:integer”/>
<sdf:serviceData name=“lastResult” type=“xsd:integer”/>
<sdf:serviceData name=“location” type=“xsd:string”/>
<sdf:serviceData name=“speed” type=“xsd:integer”/>
<sdf:serviceData name=“freeSpace” type=“xsd:integer”/>
<sdf:serviceData name=“accessControlPolicy”
type=“tns:PolicyType”/>
</gwsdl:portype>
</wsdl:defintions> 11

12. Grid Service OGSA Interface --- portType extension 12
all Grid Services must extend from a standard portType called GridService
FindServiceData
Input
QueryExpressionType: query mechanism used
QueryExpression: actual query
Output
Result of Query
SetTerminationTime
Request that termination time of this service be changed
Input: client timestamp and new termination time
Output: service timestamp and current termination time
Destroy
Explicit destruction request 12

13. Grid Service Example OGSA 13
<portType name="GridServicePortType">
<operation name="findServiceData">
<input message="tns:FindServiceDataInputMessage"/>
<output message="tns:FindServiceDataOutputMessage"/>
<fault name="QueryNotSupportedFault" message="ogsa-faults:QueryNotSupportedFault"/>
<fault name="InvalidQueryFault" message="ogsa-faults:InvalidQueryFault"/>
</operation>
<operation name="setTerminationTime"> …
<operation name="getTerminationTime">
<operation name="destroy">
</portType>
Grid Service Functionality
Database_PortType
Inherits from GridService
<portType name="Database_PortType" extends “gsdl:GridService”>
<operation name="databaseQueryOperation">
<input message="tns:myDatabaseQuery"/>
<output message="tns:myDatabaseResponse"/>
</operation>
</portType> 13

14. Grid Service OGSA Messaging Notifications 14 SOAP(web service)
Defines the message used in operation
Notifications
Dynamic monitoring
very closely related to service data
Service must implement a notificationSource interface.
Client must implement a notificationSink interface. 14

15. Grid Service OGSA GSH & GSR & Resolves GSH into GSR Factory 15
globally Unique URL
identifies the instance for all time
Location of the Grid Service only
Resolves GSH into GSR
Optionally, the client can do it by itself
Interface: FindByHandl
Input: GSH & unsatisfactory GSRs
Output: GSR
Factory
CreateService()
Input:
TerminationTime
ServiceParameters (specific to a service)
Output: ServiceTimestamp information & Service Locator (to get GSH)
many different forms (WSDL…)
Possible to communicate with Grid Service
& 15

16. Grid Service Example OGSA 16 Community Registry Mining Factory
Database
Service
BioDB 1
Compute Service Provider
User
Application . .
Database
Service
Database
Factory
BioDB n
Storage Service Provider 16

17. Grid Service Example OGSA Service Deployment “I want to create
Community
Registry
Mining
Factory
WDSL
Database
Service
Service Deployment
BioDB 1
Compute Service Provider
User
Application . .
Definition
“I want to create
a personal database
containing data on
e.coli metabolism”
Database
Service
Database
Factory
BioDB n
Storage Service Provider 17

18. Grid Service Example OGSA “I want to create 18 Find Mining Service,
Database Service
GSH
Community
Registry
Mining
Factory
Database
Service
BioDB 1
Compute Service Provider
User
Application . .
“I want to create
a personal database
containing data on
e.coli metabolism”
Database
Service
Database
Factory
BioDB n
Storage Service Provider 18

19. Grid Service Example OGSA 19
m_instance
d_instance
“Create a data mining service with initial lifetime 10”
“Create a
database with initial lifetime 1000”
Community
Registry
Mining
Factory
Database
Service
GSH
BioDB 1
Compute Service Provider
User
Application . .
Database
Service
Database
Factory
GSH
BioDB n
Storage Service Provider 19

20. Grid Service Example OGSA 20 Community Registry Mining Factory
Database
Service
Query
m_instance
d_instance
Notifikation
GSH
BioDB 1
Keepalive
Results
Compute Service Provider
User
Application . .
Database
Service
Database
Factory
Notifikation
BioDB n
Storage Service Provider 20

21. Grid Service Example OGSA 21 Community Registry Mining Factory
Database
Service
m_instance
BioDB 1
Compute Service Provider
User
Application . .
Notify me, if complete
Keepalive
Database
Service
Database
Factory
BioDB n
d_instance
Storage Service Provider 21

22. Make WS Stateful OGSA WSRF OGSA requires 'stateful services‘
WSRF extends Web Services
Developed by OASIS
Grid Service
based on Web Service
Review: Useful for the Clain Operations(realy?) 22

23. WSRF: It's all about state
OGSA
WSRF: It's all about state 23

24. WSRF: It's all about state
OGSA
WSRF: It's all about state 24

25. WSRF = Web Service+Resource
OGSA
WSRF: It's all about state
WSRF = Web Service+Resource 25

26. The WSRF specification
OGSA
The WSRF specification
WS-ResourceProperties
A resource is composed of zero or more resource properties
Filename, Size, and Descriptors…
WS-ResourceLifetime
Resources have non-trivial lifecycles
WS-ServiceGroup
groups of Web Services & groups of WS-Resources
WS-BaseFaults
standard way of reporting faults when something goes wrong during a WS-Service invocation 26

27. Related specifications
OGSA
Related specifications
WS-Addressing
we can use WS-Addressing to address
a Web service + resource pair (a WS-Resource).
WS-Notification
notification producer
notification consumers 27

28. OGSA
Architecture Review 28

29. OGSA
Architecture Review 29

30. OGSA
References
The Open Grid Services Architecture, Version
The Physiology of the Grid -- Ian Foster, Carl Kesselman, Jeffrey M. Nick, Steven Tuecke
OGSA Rising, -- Ian Foster, Argonne National Laboratory
Grid Services Overview, -- Keith R. Jackson, Distributed Systems Department, Lawrence Berkeley National Lab
The Grid Enabling Resource Sharing within Virtual Organizations, -- Ian Forster
-- Tutorial from globus 30

31. OGSA
Danke 31