Education as a Web Service Technology, Experience & Futures Geoffrey Fox Chief Scientist Anabas Inc. Professor of Computer Science, Informatics, Physics and Director PTLIU Laboratory.
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Education as a Web Service Technology, Experience & Futures Geoffrey Fox Chief Scientist Anabas Inc. Professor of Computer Science, Informatics, Physics and Director PTLIU Laboratory for Community Grids Indiana University, Bloomington IN 47404 http://grids.ucs.indiana.edu/ptliupages/presentations [email protected] uri="gxos:/ptliupages/presentations/diste dtalkfeb02" email="[email protected]" 11/6/2015 1 Teaching Jackson State Fall 97 to Fall 2001 JSU Syracuse 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 2 The Virtual University Motivated either by decreased cost or increased quality of learning environment Will succeed due to market pressures (it will offer the best product) Assume that as with text books, only a few pedagogically excellent teachers will produce lectures; only a few charismatic souls deliver them “Centers of Excellence” (including “One Professor Virtual University”) are natural entities to produce and deliver classes supported by good technology and rich graphics/multi-media (instruction design) University acts as an integrator putting together a set of classes where it may only teach some 20% but acts as a mentor to all classes its students take 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 3 Courses at Jackson State Taught using Tango/Anabas since fall 97 over Internet twice a week from Syracuse/FSU/Indiana • Course material same style as online material for in-university classes • Curricula, Homework, Grading, Facilities done by “me” • Students get JSU NOT Syracuse/Indiana Credit Jackson State major MSI (Minority Serving) University with many computer science graduates Do not compete with base courses but offer addon courses with “leading edge” material (Web Technology, modern scientific computing) which give JSU (under)graduates skills that are important in their career Fall 99 Semester CPS640 offered to 40 students in 5 distant places and separately 40 at Syracuse 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 4 What did this lead to? Jackson State students got access to curricula that was not otherwise available to them Developed quite good Information Technology and computational science curricula Jackson State faculty acted as mentors in course and now teach some of material in their own courses and to other MSI colleges • Make rapidly changing and important curricula available to an MSI network -- could dramatically improve curricula opportunities for MSI students • JSU has institutional commitment to area Used in High School Java, DoD wide training and Winter 00/01 semester as part of ERDC Graduate Institute Supports migrant teachers -- I have delivered course spring 00 semester from Syracuse, FSU and ERDC, Vicksburg 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 5 Saturday Java Academy http://old-npac.ucs.indiana.edu/projects/k12javaspring99/ 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 6 Fall 2001 Technology Large Room Access Grid Personal Access Grid + Anabas Community A/V: The Access Grid 11/6/2015 Desktop A/V uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 7 Lessons from Past “True” Shared Event flexible but too much work for most cases Shared Display – nearly always works Shared Export – SVG PDF HTML X3D etc. can be reused Integrate synchronous and asynchronous collaboration Do not build into browser as not a reliable or standard virtual machine Build around uniform publish-subscribe style XML Event Model supporting archiving, customization, filtering – apply to all collaboration modes Later we realized need to integrate with Peer to Peer and Web Services (straightforward as XML event model fits these architectures) 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 8 Batik Viewer on PC PowerPoint can be converted to SVG via Illustrator or Web export 11/6/2015 SVG Sharing PC to PDA uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 9 Object Web View of the World “Everything electronic” is a resource • • • • Computers Programs Data (from sensors to this presentation to email to databases) People “Everything electronic” is a distributed object “All External Interfaces” are defined in XML whether this is a property (data-structure) or a method (service, function, subroutine) • We can assume that a data-structure property has getproperty() and setproperty(value) methods to act as interface • All resources have interfaces All resources are linked by messages with format and transport protocol to be discussed but as interfaces defined in XML, message structure must be specifiable in XML 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 10 The 3 Critical XML Interfaces Data (sort of dumb) Information User Rendering Raw Raw Data Resources (Virtual) XML Data Interface Server Processing Information/Knowledge (Virtual) XML Information Interface Render to XML Display Format (Virtual) XML Rendering Interface Clients 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 11 XML Skin Message Or Event Soft Soft Based ware ware Inter Connection Resource XML Skin Resource Data base XML Defined Resources connected by XML defined messages Implementation of resource and connection may or may not be XML 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 12 What is a Web Service A web service is a computer program running on either the local or remote machine with a set of well defined interfaces (ports) specified in WSDL In principle, computer program can be in any language (Fortran .. Java .. Perl .. Python) and the interfaces can be implemented in any way what so ever • Interfaces can be method calls, Java RMI Messages, CGI Web invocations, totally compiled away (inlining) but The simplest implementations involve XML messages (SOAP) and programs written in net friendly languages like Java and Python Web Services separate the meaning of a port (message) interface from its implementation – WSDL Interfaces are virtual XML 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 13 Role of Web Services Define interfaces of web applications so that computer-computer interactions are enabled • Defines virtual XML for all system and application services WSDL is XML versions of Class and Method definitions SOAP is XML version of message UDDI or WSIL catalogs WSDL based services enabling precise linkage of them ( WSFL and WSCL are candidate linkage languages WSDL interfaces Security WSDL interfaces 11/6/2015 Payment Credit Card Catalog Warehouse shipping uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 14 Raw Resources Raw Data Raw Data (Virtual) XML Data Interface Web Service (WS) WS WS WS etc. XML WS to WS Interfaces WS WS WS WS WS (Virtual) XML Knowledge (User) Interface Render to XML Display Format Clients 11/6/2015 (Virtual) XML Rendering Interface uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 15 Some General Grid or Web Services 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 16 Some Science Web Services These build on general (community) web services 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 17 Education as a Web Service Can link to Science as a Web Service and substitute educational modules “Learning Object” XML standards already exist from IMS/ADL http://www.adlnet.org – need to update architecture Web Services for virtual university include: Registration Performance (grading) Authoring of Curriculum Online laboratories for real and virtual instruments Homework submission Quizzes of various types (multiple choice, random parameters) Assessment data access and analysis Synchronous Delivery of Curricula Scheduling of courses and mentoring sessions Asynchronous access, data-mining and knowledge discovery Learning Plan agents to guide students and teachers 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 18 UDDI & Content Management Consider content to consist of “curricula pages” and meta-data We have meta-data stored in LDAP, flat files, UDDI, databases (Oracle 9i), XML databases, WebDAV, Web page header tags, JMS topics Content meta-data and content linked by URI. In general content & meta-data stored separately Managing meta-data is hardest problem – view as federation of multiple independent heterogeneous databases with separate access and lookup services • Each component is a web service supporting query, access, store etc. UDDI will be replaced by this more general view Most of education is meta-data ……. 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 19 LCMS as a Web Service For meta-data, just build federated database as a Web Service • Storage, update, lookup of objects • Registration of different control engines For content, if W3C DOM and Java API as for SVG and “decent” XHTML browsers, then can wrap DOM as a web service for all interface functions • Can of course do this for IE5 but document object model unreliable Build collaboration systems as sharing Web Service interfaces (not COM or other object API) 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 20 Integration of XML/Web Services into an Enterprise I You are the CIO of a little known state’s (call it Xanadu) education system and been tasked to position it as a 2005 leader in technology enhanced education Your initial review reveals a multitude of incompatible existing information systems distributed over Xanadu’s 50 campuses Your cradle to grave community education mandate (which got the Governor elected) implies integration of all aspects of education in your information system You note that performance issues are much less important in this application than interoperability (it currently takes months to get anything done so what's an extra millisecond or so at a WSDL interface) , so even in current primitive/immature state Web services look attractive 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 21 Enterprise Web Services II We start a requirements analysis and a catalog of existing “raw resources”. This will lead to the clean internal XML(WSDL) interfaces XIF and to the external XML interfaces (XEF) to the raw resources What is Xanadu Internal Framework (XIF) ? We find that The Grid Forum community has defined computing interfaces which we will adopt to support infrastructure needed for use of simulations and data repositories in curriculum We find that Microsoft, the Liberty Alliance and the Grid have Security schemes but are relieved that with a little bit of XSLT (transformations) we can map between them and can define authentication & access control as a Web Service We join the IMS consortium and adopt their standards for learning meta-data and user related information We adopt the AICC and ADL SCORM standards for “learning objects” (course pages) 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 22 Enterprise Web Services III We define Xanadu educational agents which use XIF plus RDF/DAML-OIL to be able to capture educational goals We expect commercial standards compliant solutions will be available for most other needed Educational web services We find that we must interface with a dreadful collection of external raw resources coming from legacy PeopleSoft SAP Oracle and Microsoft products • As our new model is object (XML) and open standards based we build a separate XII (Xanadu Information Infrastructure) supporting XIF objects We analyze structure of legacy systems and their relation to XIF and define the external framework XEF which captures much of the raw resources • This XEF Schema is extensible to capture quirks of each legacy system • We build a set of Web services that convert XEF into XIF We inform vendors that we will only install XIF compliant systems in all future purchases 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 23 CollabWS: Collaboration as a Web Service This includes Audio-Video conferencing, Instant Messengers, shared applications and tools There are basic standards H323 and SIP There are peer to peer collaboration approaches like JXTA from Sun The various commercial products – Anabas …Centra …Webex … Groove Networks effectively defines some shared application interfaces CollabWS defines a superset of collaboration properties and subservices in XML/WSDL Then you provide several bindings of collabws.wsdl to new transports and old ones (binary H323) 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 24 H323 SIP JXTA 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 25 SIP H323 JXTA SIP H323 11/6/2015 JXTA uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 26 A Typical SIP Message REGISTER sip:registrar.biloxi.com Via: SIP/2.0/UDP 10.4.1.4:5060 To: Bob (sip:[email protected]) From: Bob (sip:[email protected]);tag=456248 Call-ID: [email protected] CSeq: 1826 REGISTER Contact: (sip:[email protected]) Expires: 7200 Contact-Length: 0 Initially build a wrapper that accepts such messages and converts to ….. 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 27 Collaboration as a Web service - now 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 28 SIP as XML <sipasxml> <register> sip:registrar.biloxi.com</register> <via> SIP/2.0/UDP 10.4.1.4:5060</via> <to> Bob (sip:[email protected]) </to> <from tag="456248" > Bob (sip:[email protected]) </from> <call-id> [email protected] </call-id> <cseq> 1826 REGISTER </cseq> <contact> (sip:[email protected]) </contact> <expires> 7200 </expires> <contact-length> 0 </contact-length> </sipasxml> So this is either an internal format to which we map SIP messages or it is an external format used for Collaboration Web Service 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 29 Future Collaboration Web Service 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 30 Messaging/Events as a Web Service We can implement messaging subsystem (between WSDL resources) with either direct messages or by a queued system where you publish messages to queues and subscribe as receiver to particular queues There are many different publish/subscribe models • JMS is a cluster of central servers • JXTA is a very dynamic Peer to Peer model where pipes are queues and topics (metadata) are service advertisements One could have different ports in Messaging/Event Web Service corresponding to the different JMS or JXTA fault tolerance/reliability semantics • Could use JMS as long distance “carrier” between JXTA peers • JXTA provides higher performance than JMS for nearby recipients 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 31 Event Web Service Destination Source Matching Routing Web Service 1 WSDL Ports (Virtual) Queue Filter workflow Web Service 2 WSDL Ports Filter is mapping to PDA or slow communication channel (universal access) – see our PDA adaptor Workflow natural as all messages “intercepted” by Event Web Service Routing illustrated by JXTA Destination-Source matching illustrated by JMS 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 32 Broker Network Software multicast P2P: Brokers are clients Broker Broker Resource Broker Broker Broker Data base Brokers created dynamically when needed for a new cluster of resources Broker 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 33 Narada JXTA/JMS Integration http://grids.ucs.indiana.edu/ptliupages/projects/narada/ Is a network of event brokers which can reliably deliver XML specified events Using openJMS selection module, becomes a distributed or conventional Java Message Service Linking special JXTA proxies, it can link JXTA communities Think of JXTA JMS and “native” Narada as different bindings (ports) in an event/messaging web service 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 34 Database Database JXTA Event Broker Event Broker JMS Event Broker Peer to Peer Grid Event Broker Community Grid 11/6/2015 JXTA Peer to Peer Grid uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 35 PDA Collaboration Adaptor 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 36 MyProfessor on the PDA 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 37 Component –based Portal Web Services provide a component model for the middleware (see large “common component architecture” effort in Dept. of Energy) Should match each WSDL component with a corresponding user interface component Thus one “must use” a component model for the portal with again an XML specification (portalML) of portal component 11/6/2015 uri="gxos:/ptliupages/presentations/distedtalkfeb02" email="[email protected]" 38