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

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

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

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

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

OGSA OGSA Architecture 6

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

OGSA Architecture Review 28

OGSA Architecture Review 29

OGSA References The Open Grid Services Architecture, Version 1.0 -- http://forge.gridforum.org/projects/ogsa-wg 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 http://http://gdp.globus.org/gt4-tutorial/ -- Tutorial from globus 30

OGSA Danke 31