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0- 1 Internet Technologies ICEN2202 PART 4 (Grid Computing (OGSA, WSRF) ) Abdullah Said Alkalbani University of Buraimi.

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Presentation on theme: "0- 1 Internet Technologies ICEN2202 PART 4 (Grid Computing (OGSA, WSRF) ) Abdullah Said Alkalbani University of Buraimi."— Presentation transcript:

1 0- 1 Internet Technologies ICEN2202 PART 4 (Grid Computing (OGSA, WSRF) ) Abdullah Said Alkalbani University of Buraimi

2 Open Grid service Architecture (OGSA) OGSA 2 OGSA is a distributed interaction and computing architecture based around services, assuring interoperability on heterogeneous systems so that different types of resources can communicate and share information. OGSA has been described as a refinement of the emerging Web Services architecture, specifically designed to support Grid requirements

3 OGSA 3 An open, service-oriented architecture (SOA) – Dynamic service/resource creation and destruction Built on a Web services infrastructure Build grids from small number of standards- based components Customizable – Support for dynamic, domain-specific content… – …within the same standardized framework

4 4 Why Use an SOA? Logical view of capabilities Relatively coarse-grained functions Reusable and composable behaviors Encapsulation of complex operations Naturally extendable framework Platform-neutral – machine and OS OGSA

5 SOA & Web Services: Key Benefits OGSA 5 SOA Flexible −Locate services on any server −Relocate as necessary −Prospective clients find services using registries Scalable −Add & remove services as demand varies Replaceable −Update implementations without disruption to users Fault-tolerant −On failure, clients query registry for alternate services SOA Flexible −Locate services on any server −Relocate as necessary −Prospective clients find services using registries Scalable −Add & remove services as demand varies Replaceable −Update implementations without disruption to users Fault-tolerant −On failure, clients query registry for alternate services Web Services Interoperable −Growing number of industry standards Strong industry support Reduce time-to-value −Robust development tools for Web services are available −Decrease learning & implementation time Embrace and extend −Leverage effort in developing and driving consensus on standards −Focus limited resources on augmenting & adding standards as needed Web Services Interoperable −Growing number of industry standards Strong industry support Reduce time-to-value −Robust development tools for Web services are available −Decrease learning & implementation time Embrace and extend −Leverage effort in developing and driving consensus on standards −Focus limited resources on augmenting & adding standards as needed

6 Virtualizing Resources OGSA 6 Resources Web services Access Storage Sensors Applications Information Computers Resource-specific Interfaces Common Interfaces Type-specific interfaces

7 A Service-Oriented Grid OGSA 7 Virtualized resources Grid middleware services Brokering Service Registry Service Data Service CPU Resource Printer Service Job-Submit Service Compute Service Notify Advertise Application Service

8 OGSA example user cases OGSA design is driven by a set of functional requirements, which themselves are informed by the use cases. These use cases cover infrastructure and application scenarios for both commercial and scientific areas. Examples are listed in the next slide OGSA 8

9 Use cases User casesSummary Commercial Data CenterManages thousands of IT resources, while reducing management costs and increasing resource utilization. Online Media and EntertainmentDelivering an entertainment experience Grid LiteExtends the use of Grids to small devices—PDAs and cell phones. Virtual OrganizationGives its members access to various computational, instrument-based data and other types of resources. Grid PortalProvides an end-user view of the collected resources available. IT Infrastructure ManagementJob execution, cycle sharing and provisioning scenarios. Application Use CasesPeer-to-Peer PC Grid computing, file sharing and content delivery scenarios. OGSA 9 For full a detail see GFD-I.080:The Open Grid Services Architecture, Version 1.5

10 10 OGSA Capabilities Security Cross-organizational users Trust nobody Authorized access only Security Cross-organizational users Trust nobody Authorized access only Information Services Registry Notification Logging/auditing Information Services Registry Notification Logging/auditing Execution Management Job description & submission Scheduling Resource provisioning Execution Management Job description & submission Scheduling Resource provisioning Data Services Common access facilities Efficient & reliable transport Replication services Data Services Common access facilities Efficient & reliable transport Replication services Self-Management Self-configuration Self-optimization Self-healing Self-Management Self-configuration Self-optimization Self-healing Resource Management Discovery Monitoring Control Resource Management Discovery Monitoring Control OGSA OGSA “profiles” Web services foundation OGSA

11 Execution Management OGSA Submit the job 3. Select from or deploy required resources Job 4. Manage the job 1. Describe the job JSDL Job CDL  The basic problem  Provision, execute and manage services/resources in a grid  Allow for legacy applications  The basic problem  Provision, execute and manage services/resources in a grid  Allow for legacy applications

12 12 Describing a Job Submission: JSDL Job Submission Description Language (JSDL) – A language for describing the requirements of jobs for submission A JSDL document describes the job requirements – Job identification information – Application (e.g., executable, arguments) – Required resources (e.g., CPUs, memory) – Input/output files Job IT Infrastructure JSDL OGSA

13 Data Services OGSA 13 The basic problem – Manage, transfer and access distributed data services and resources Some use-cases – Replicating data for performance and reliability using high- performance data transfer – Federating distributed data via a common access interface – Managing file-based data and corresponding relational metadata Issues to address – Many different data “types” and protocols – Multiple possible use-cases, from high-energy physics to business – How can we describe the data? – How can we find the data? – Where is the data needed?

14 Basic Interfaces of Data Services Storage Management Data Access Data Transfer Metadata catalog Replica management Cache management OGSA 14

15 Resource Management OGSA 15 Provides a framework to integrate resource management functions −interfaces, services, information models, etc. Enables integrated discovery, monitoring, control, etc. Provides a framework to integrate resource management functions −interfaces, services, information models, etc. Enables integrated discovery, monitoring, control, etc. High-level management services (GGF) Domain-specific capabilities OGSA Access to manageability (OASIS, DMTF) Information models (DMTF, SNIA, etc.) Resources WSDM, WS-Management WSRF/WSN, WS-Transfer/Eventing Data services Security services Execution Management services Application- specific

16 Self-Management OGSA 16 Self- Management Monitoring Projection Analysis Action Policy SLA Self-configuration: Automatically adapt to changes in the environment : −e.g. Deploy/undeploy resources as load changes Self-configuration: Automatically adapt to changes in the environment : −e.g. Deploy/undeploy resources as load changes Self-optimization: Automatically tune system to best meet user or business needs −Uses service-level agreements (SLAs) Self-optimization: Automatically tune system to best meet user or business needs −Uses service-level agreements (SLAs) Self-healing: Automatically detect & correct problems −Component failures −Security violations −etc. Self-healing: Automatically detect & correct problems −Component failures −Security violations −etc.

17 Information Services OGSA 17 Execution management Resource reservation Problem determination Accounting Application monitoring Load balancing Service discovery Consumers Information Services Reliable Secure Efficient Provide management and access facilities for information about applications and resources in the grid environment Producers Asynchronous notification Retrieval Registry Logger

18 Security Services OGSA 18  Authorization, roles, and access privileges  Locally (site) managed  Based on SAML and XACML security standards  Implementations provide credential mapping  Working with GGF Security Area groups  Authorization attributes for grids  Developing OGSA security profiles PKI certificate WS-Security WS-Addressing OGSA security profiles

19 19 Specifications Landscape: April 2006 SYSTEMS MANAGEMENT UTILITY COMPUTING GRID COMPUTING Core Services Web Services Foundation WS-Addressing Privacy WS-BaseNotification CIM/JSIM WSRF-RAP WSDM WS-Security Naming OGSA-EMSOGSA Self Mgmt GFD-C.16 GGF-UR Data Model HTTP(S)/SOAP Discovery SAML/XACML WSDL WSRF-RL Trust WS-DAI VO Management Information Distributed query processing ASP Data Centre Use Cases & Applications CollaborationMulti MediaPersistent Archive Data Transport WSRF-RP X.509 StandardEvolvingGapHole OGSA

20 A Short Note about OGSI OGSA 20 Open Grid Services Infrastructure (OGSI) is the standard that describe the implementation of the first version of OGSA However, the web service extension described in OGSI is not accepted by the Web service world Therefore, the new version of OGSA leads to the new implementation which is WSRF (Web Service Resource Framework)

21 Web Service and OGSA OGSA 21 Web service architecture is the best option for implement the Grid. Usually, web service is “stateless”. This means that the Web service can’t "remember” information, or keep state, from one invocation to another. And… there are no standard way to implement a “stateful” web service. However, OGSA requires “stateful” web services. Something had to be done ! WSRF is the result of the effort to standardize the process of creating a stateful web service.

22 Web Service Invocation OGSA 22

23 Stateless Web Service OGSA 23

24 Stateful Web Service OGSA 24

25 WSRF OGSA 25 Web Service Resource Framework – A stateful web service State information is kept as Resource – Resources have Properties that define state – Properties can be add/remove/change dynamically Extends web service standards

26 Web Service and Resource OGSA 26

27 Resource Representation OGSA 27 Resource stores its information in Resource Properties (RPs) The structure of Resource is included in a WSDL file of a WSRF web service An instance of a Resource is stored as Resource Property Document

28 Resource Property Document OGSA 28

29 WSRF Specification OGSA 29  WSRF is a collection of specifications  Core  WS-ResourceProperties  Specifies how resource properties are defined and accessed  WS-ResourceLifetime  Provides basic mechanisms to manage the lifecycle of resources  WS-ServiceGroup  Allow us to group different services together and access them through a single point of entry  WS-BaseFaults  Provides a standard way of reporting faults  Related  WS-Notification  WS-Addressing

30 WS-ResourceProperties OGSA 30 Specifies common operations for interacting with resource properties (RPs) A web service can include these operations (portTypes) into its service to increase functionality As a result, a web service does not have to implement getter/setter-like method for manipulating its resources

31 WS-ResourceProperties portTypes OGSA 31 GetResourceProperty – Provides access to the value of any RPs GetMultipleResourceProperties – Provides access to the value of multiple RPs at once SetResourceProperties – Provides a uniform way to modify RPs such as update, insert, and delete QueryResourceProperties – Allow us to perform queries on the RP document

32 Introduction to WSRF Questions so far? Introduction to WSRF – What it is, why it was developed – Relations to OGSI, OGSA – Definitions

33 What it is? announced at GlobusWorld 04 by the Globus Alliance, IBM and HP WSRF is a set of five Web services specifications to model and manage state in a Web services context – ResourceLifetime – ResourceProperties – BaseFaults – RenewableReferences – ServiceGroup... which together with the Notification Spec retain all of the essential functional capabilities present in OGSI

34 Why it was developed? WSRF effectively completes the convergence of the Web service and Grid computing communities

35 Why it was developed? Criticisms of OGSI from the Web services community : – Too much stuff in one spec => functionality partitioned into a family of composable specifications – Does not work well with existing Web services tooling => WSRF tones down the usage of XML Schema – Too object oriented: OGSI v1.0 models a stateful resource as a Web service that encapsulates the resource’s state, with the identity and lifecycle of the service and resource state coupled => WSRF makes an explicit distinction between the “service” and the stateful entities acted upon by that service

36 Relation from WSRF to... OGSA: WSRF mechanisms will enable OGSA OGSI: WSRF restates OGSI concepts in WS terms OGSIWSRF Grid Service Reference (GSR)WS-Addressing Endpoint Reference Grid Service Handle (GSH)WS-Addressing Endpoint Reference HandleResolver portTypeWS-RenewableReferences Service data elements (SDE)WS-ResourceProperties GridService lifetime managementtWS-ResourceLifeCycle Notification portTypesWS-Notification Factory portTypeTreated as a pattern ServiceGroup portTypesWS-ServiceGroup Base fault typeWS-BaseFaults

37 Definitions in WSRF WS-Resource = Web Service + stateful resource which is used in the execution of message exchanges Stateful resource: – Specific set of state data expressible as XML doc – Well defined lifecycle – Known to and acted upon by one or more web services Implied resource pattern = specific kind of relationship between web service and stateful resource – Stateful resource implicit input for the execution of the message request (static or dynamic) – Pattern means that relationship is codified by a set of conventions – in particular XML, WSDL and WS-Addressing

38 WSRF in detail WSRF Concepts in Detail – how WS-Addressing is used – have a closer look on the specs

39 Usage of WS-Adressing I C Service Requestor WS request response C AB

40 Usage of WS-Adressing II C … some message Service Requestor WS C message AB C

41 Resource-Lifecycle I The lifecycle of a WS-Resource is defined as the period between its instantiation and its destruction. Creation of a WS-Resource: – trough any Web service capable of bringing one or more WS-Resources into existence – response message typically contains at least one endpoint reference that refers to the new WS-Resource or places it into a registry for later retrival – a message exchange is only considered a WS- Resource factory operation if it results in the actual creation of the WS-Resource referred to in the returned WSResource-qualified endpoint reference

42 Resource-Lifecycle II immediate destruction request message: response message: scheduled destruction mechanisms uses properties of the WS-Resource to – query current time – Determine current termination time

43 Resource Lifecycle III Setting initial termination Time – via special XML element in the creation request message Requesting Change to Termination Time – SetTerminationTimeRequest message Notification of Resource Destruction – via subscription to topic ResourceTermination All time specifications are in UTC

44 Notifications I notification using a topic-based publication/subscription pattern standard set of message exchanges that define the roles of NotificationProducer and NotificationConsumer standard way to name and describe Topics

45 Notifications II Topic = categorize Notifications and their related NotificationMessage schemas – part of the matching process A B C WS with topics: goingOffLine SystemError Subscribe C to SystemError Subscribe B to goingOffLine Producer Consumer

46 Notifications III A B C WS with topics: goingOffLine SystemError Broker Consumer msg1 msg2 Publisher A Publisher B Publish msg1 to topic SystemError Publish msg2 to topic SystemError

47 Notifications IV Broker interface: – intermediary Web Service that decouples NotificationConsumers from Publishers Demand-based publishing: – producing notifications may be costly – Broker subscribes to the Publisher – When no subscribers for the messages it pauses its subscription resumes when there are subscribers

48 Resource Properties I defines the type and values of a WS-Resource’s state that can be viewed and modified Resource properties document acts as a view on the actual state Described using XML Schema

49 Resource Properties II Defined Messages: – GetResourceProperty – GetMultipleResourceProperties – SetResourceProperties Insert,update,delete – QueryResourceProperties Using a query expression such as Xpath

50 Base Fault I Target: specifying Web services fault messages in a common way defines an XML Schema type for a base fault, along with rules for how this fault type is used

51 Base Fault II xsd:dateTime wsa:EndpointReferenceType ? xsd:string ? xsd:string * wsbf:BaseFault *

52 Service Groups I defines means by which WS can be grouped together for a domain specific purpose ServiceGroup is a WS-Resource, which represents a collection of other Web services MembershipContentRule: constraints on membership of the service group – E.g. membership can be restricted to members that implement a particular interface – no MembershipContentRule elements are specified, the members of the ServiceGroup are unconstrained.

53 Service Groups II ServiceGroupRegistration interface defines the message exchanges allow a requestor to add entries to a ServiceGroup (Add Operation) Notification of ServiceGroup Modification – Topic ServiceGroupModification – Notification Messages EntryAdditionNotification EntryRemovalNotification

54 Renewable Reference No specification yet! define mechanisms that can be used to renew an endpoint reference that has become invalid – reference may contain not only addressing but also policy information concerning interactions with the service How? – Decorating endpoint references with information necessary to retrieve a new endpoint reference

55 Globus WSRF Preview early preview of the Java WSRF Core implementation – none of the higher-level services GT 4.0 based on WSRF should become available in Quartal 4 of 2004

56 Example I What is required to implement a new service? – WSDL – Service impl. – Resource impl. – ResourceHome – Client – Configuration/Installation

57 Example II – Counter Scenario

58 WSDL I - Properties

59 WSDL II - Interface

60 Service Implementation public _createCounterResponse createCounter(_createCounterRequest request) { ResourceContext ctx = null; CounterHome home = null; ResourceKey key = null; ctx = ResourceContext.getResourceContext(); home = (CounterHome) ctx.getResourceHome(); key = home.create(); EndpointReferenceType epr = AddressingUtils.createEndpointReference(ctx, key); _createCounterResponse response = new _createCounterResponse(); response.setEndpointReference(epr); return response; }

61 Service Implementation - add public int add(int arg0) throws RemoteException { Object resource = ResourceContext.getResourceContext().getResource(); Counter counter = (Counter) resource; int result = counter.getValue(); result += arg0; counter.setValue(result); return result; }

62 Resource Implementation public class PersistentCounter extends Counter implements PersistentResource { public void setValue(int value) { super.setValue(value); store(); } public Object create() throws Exception { Object key = super.create(); store(); return key; } public void load(ResourceKey key) throws ResourceException { …} public void store() throws ResourceException { … } public void remove() throws ResourceException { … } }

63 ResourceHome public class CounterHome extends PersistentResourceHome { public ResourceKey create() throws Exception { Counter counter = (Counter)createNewInstance(); counter.create(); ResourceKey key = new SimpleResourceKey(keyTypeName, counter.getID()); this.resources.put(key, counter); return key; }

64 Conclusions WSRF refactors OGSA concepts – some parts are still missing – Grid and Web communities can move forward on a common base WS-Resource: Web service that acts upon stateful resources


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