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Web 2.0 in a Web Services and Grid Context
Part I: CTS2007 Web 2.0 Tutorial
CTS 2007Embassy Suites Hotel-Lake Buena Vista Resort, Orlando, FL, USA
May 25 2007
Geoffrey Fox and Marlon PierceComputer Science, Informatics, Physics
Pervasive Technology LaboratoriesIndiana University Bloomington IN 47401
[email protected]://www.infomall.org
Applications, Infrastructure, Technologies
This field is confused by inconsistent use of terminology – this is what I mean
Web Services, Grids and Web 2.0 (Enterprise 2.0) are technologies
These technologies combine and compete to build electronic infrastructures termed e-infrastructure or Cyberinfrastructure
e-moreorlessanything is an emerging application area of broad importance that is hosted on the infrastructures e-infrastructure or Cyberinfrastructure
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e-moreorlessanything is the Application ‘e-Science is about global collaboration in key areas of science,
and the next generation of infrastructure that will enable it.’ from its inventor John Taylor Director General of Research Councils UK, Office of Science and Technology
Similarly e-Business captures an emerging view of corporations as dynamic virtual organizations linking employees, customers and stakeholders across the world.
Net Centric computing is a similar DoD vision This generalizes to e-moreorlessanything A deluge of data of unprecedented and inevitable size must be
managed and understood. People (see Web 2.0), computers, data and instruments must be
linked. On demand assignment of experts, computers, networks and
storage resources must be supported
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Role of Electronic infrastructure Supports integration of data, people, computers for
• Distributed Science or e-Science (US, Cyberinfrastructure)• Command and Control (US, Global Information Grid)• e-Business e-Science etc. (Europe, e-Infrastructure)
Exploits Internet technology (Web2.0) adding (via Grid technology) management, security, supercomputers etc.
It has two aspects: parallel – low latency (microseconds) between nodes and distributed – highish latency (milliseconds) between nodes
Parallel needed to get high performance on individual 3D simulations, data analysis etc.
Distributed aspect integrates already distinct components Electronic infrastructure is in general a distributed collection
of parallel systems and presented as services (often Web services) that are “just” programs or data sources packaged for distributed access
Not so controversial Ideas Distributed software systems are being “revolutionized” by
developments from e-commerce, e-Science and the consumer Internet. There is rapid progress in technology families termed “Web services”, “Grids” and “Web 2.0”
The emerging distributed system picture is of distributed services with advertised interfaces but opaque implementations communicating by streams of messages over a variety of protocols• Complete systems are built by combining either services or predefined/pre-
existing collections of services together to achieve new capabilities
Currently Grids are built using Web Services with possible enhancements like WSRF which we call Narrow or Web service Grids
We expect that future systems will be built as Broad Grids which are a collection of services mixing Web Service and Web 2.0 architectures
Web 2.0 and Web Services I Web Services have clearly defined protocols (SOAP) and a well
defined mechanism (WSDL) to define service interfaces• There is good .NET and Java support• The so-called WS-* specifications provide a rich sophisticated but
complicated standard set of capabilities for security, fault tolerance, meta-data, discovery, notification etc.
“Narrow Grids” build on Web Services and provide a robust managed environment with growing adoption in Enterprise systems and distributed science (so called e-Science)
Web 2.0 supports a similar architecture to Web services but has developed in a more chaotic but remarkably successful fashion with a service architecture with a variety of protocols including those of Web and Grid services• Over 400 Interfaces defined at http://www.programmableweb.com/apis
Web 2.0 also has many well known capabilities with Google Maps and Amazon Compute/Storage services of clear general relevance
There are also Web 2.0 services supporting novel collaboration modes and user interaction with the web as seen in social networking sites, portals, MySpace, YouTube,
Web 2.0 and Web Services II I once thought Web Services were inevitable but this is
no longer clear to me Web services are complicated, slow and non functional
• WS-Security is unnecessarily slow and pedantic (canonicalization of XML)
• WS-RM (Reliable Messaging) seems to have poor adoption and doesn’t work well in collaboration
• WSDM (distributed management) specifies too much There are de facto standards like Google Maps and
powerful suppliers like Google which “define the rules” One can easily combine SOAP (Web Service) based
services/systems with HTTP messages but the “lowest common denominator” suggests additional structure/complexity of SOAP will not easily survive
Old and New (Web 2.0) Community Tools e-mail and list-serves are oldest and best used Kazaa, Instant Messengers, Skype, Napster, BitTorrent for P2P
Collaboration – text, audio-video conferencing, files del.icio.us, Connotea, Citeulike, Bibsonomy, Biolicious manage
shared bookmarks MySpace, YouTube, Bebo, Hotornot, Facebook, or similar sites
allow you to create (upload) community resources and share them; Friendster, LinkedIn create networks• http://en.wikipedia.org/wiki/List_of_social_networking_websites
Writely, Wikis and Blogs are powerful specialized shared document systems
ConferenceXP and WebEx share general applications Google Scholar tells you who has cited your papers while
publisher sites tell you about co-authors• Windows Live Academic Search has similar goals
Note sharing resources creates (implicit) communities• Social network tools study graphs to both define communities
and extract their properties
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“Best Web 2.0 Sites” -- 2006 Extracted from http://web2.wsj2.com/ Social Networking
Start Pages
Social Bookmarking
Peer Production News
Social Media Sharing
Online Storage (Computing)
Web 2.0 Systems are Portals, Services, Resources Captures the incredible development of interactive Web
sites enabling people to create and collaborate
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Mashups v Workflow? Mashup Tools are reviewed at http://blogs.zdnet.com/Hinchcliffe/?p=63 Workflow Tools are reviewed by Gannon and Fox
http://grids.ucs.indiana.edu/ptliupages/publications/Workflow-overview.pdf Both include
scripting in PHP, Python, sh etc. as both implement distributed programming at level of services
Mashups use all types of service interfaces and do not have the potential robustness (security) of Grid service approach
Typically “pure” HTTP (REST)
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Grid Workflow Datamining in Earth Science Work with Scripps Institute Grid services controlled by workflow process real time
data from ~70 GPS Sensors in Southern California
Streaming DataSupport
TransformationsData Checking
Hidden MarkovDatamining (JPL)
Display (GIS)
NASA GPS
Earthquake
Real Time
Archival
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Web 2.0 uses all types of Services Here a Gadget Mashup uses a 3 service workflow with
a JavaScript Gadget Client
Web 2.0 APIs
http://www.programmableweb.com/apis has (May 14 2007) 431 Web 2.0 APIs with GoogleMaps the most often used in Mashups
This site acts as a “UDDI” for Web 2.0
The List of Web 2.0 API’s Each site has API and
its features Divided into broad
categories Only a few used a lot
(42 API’s used in more than 10 mashups)
RSS feed of new APIs Amazon S3 growing
in popularity
APIs/Mashups per Protocol Distribution
REST SOAP XML-RPC REST,XML-RPC
REST,XML-RPC,
SOAP
REST,SOAP
JS Other
google google mapsmaps
netvibesnetvibes
live.comlive.com
virtual virtual earthearth
google google searchsearch
amazon S3amazon S3
amazon amazon ECSECS
flickrflickrebayebay
youtubeyoutube
411sync411syncdel.icio.usdel.icio.us
yahoo! searchyahoo! searchyahoo! geocodingyahoo! geocoding
technoratitechnorati
yahoo! imagesyahoo! imagestrynttrynt
yahoo! localyahoo! local
Number ofMashups
Number ofAPIs
4 more Mashups each day For a total of 1906
April 17 2007 (4.0 a day over last month)
Note ClearForest runs Semantic Web Services Mashup competitions (not workflow competitions)
Some Mashup types: aggregators, search aggregators, visualizers, mobile, maps, gamesGrowing number of commercial Mashup Tools
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Mash Planet
Web 2.0 Architecture
http://www.imagine-it.org/mashplanetDisplay too large to be a Gadget
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Searched on Transit/TransportationSearched on Transit/Transportation
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Browser +Google Map API
Cass County Map Server
(OGC Web Map Server)
Hamilton County Map Server(AutoDesk)
Marion County Map Server
(ESRI ArcIMS)
Browser client fetches image tiles for the bounding box using Google Map API. Tile Server
Cache Server
Adapter Adapter Adapter
Tile Server requests map tiles at all zoom levels with all layers. These are converted to uniform projection, indexed, and stored. Overlapping images are combined.
Must provide adapters for each Map Server type .
The cache server fulfills Google map calls with cached tiles at the requested bounding box that fill the bounding box.
Google Maps Server
A “Grid” Workflow(built in Java!)
Uses Google Maps clients and server and non Google map APIs
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GIS Grid of “Indiana Map” and ~10 Indiana counties with accessible Map (Feature) Servers from different vendors. Grids federate different data repositories (cf Astronomy VO federating different observatory collections)
Indiana Map Grid Workflow/Mashup
Now to Portals2222
Grid-style portal as used in Earthquake GridThe Portal is built from portlets
– providing user interface fragments for each service that are composed into the full interface – uses OGCE technology as does planetary science VLAB portal with University of Minnesota
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Portlets v. Google Gadgets Portals for Grid Systems are built using portlets with
software like GridSphere integrating these on the server-side into a single web-page
Google (at least) offers the Google sidebar and Google home page which support Web 2.0 services and do not use a server side aggregator
Google is more user friendly! The many Web 2.0 competitions is an interesting model
for promoting development in the world-wide distributed collection of Web 2.0 developers
I guess Web 2.0 model will win!
Note the many competitions powering Web 2.0 Mashup Development
Typical Google Gadget Structure
… Lots of HTML and JavaScript </Content> </Module>Portlets build User Interfaces by combining fragments in a standalone Java ServerGoogle Gadgets build User Interfaces by combining fragments with JavaScript on the client
Google Gadgets are an example of Start Page technologySee http://blogs.zdnet.com/Hinchcliffe/?p=8
Web 2.0 v Narrow Grid I Web 2.0 and Grids are addressing a similar application class
although Web 2.0 has focused on user interactions
• So technology has similar requirements Web 2.0 chooses simplicity (REST rather than SOAP) to lower
barrier to everyone participating Web 2.0 and Parallel Computing tend to use traditional (possibly
visual) (scripting) languages for equivalent of workflow whereas Grids use visual interface backend recorded in BPEL
Web 2.0 and Grids both use SOA Service Oriented Architectures “System of Systems”: Grids and Web 2.0 are likely to build
systems hierarchically out of smaller systems
• We need to support Grids of Grids, Webs of Grids, Grids of Services etc. i.e. systems of systems of all sorts
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Web 2.0 v Narrow Grid II Web 2.0 has a set of major services like GoogleMaps or Flickr
but the world is composing Mashups that make new composite services• End-point standards are set by end-point owners• Many different protocols covering a variety of de-facto standards
Narrow Grids have a set of major software systems like Condor and Globus and a different world is extending with custom services and linking with workflow
Popular Web 2.0 technologies are PHP, JavaScript, JSON, AJAX and REST with “Start Page” e.g. (Google Gadgets) interfaces
Popular Narrow Grid technologies are Apache Axis, BPEL WSDL and SOAP with portlet interfaces
Robustness of Grids demanded by the Enterprise? Not so clear that Web 2.0 won’t eventually dominate other
application areas and with Enterprise 2.0 it’s invading GridsThe world does itself in large numbers!
Web 2.0 v Narrow Grid III Narrow Grids have a strong emphasis on standards and structure;
Web 2.0 lets a 1000 flowers (protocols) and a million developers bloom and focuses on functionality, broad usability and simplicity• Semantic Web/Grid has structure to allow reasoning• Annotation in sites like del.icio.us and uploading to
MySpace/YouTube is unstructured and free text search replaces structured ontologies
Portals are likely to feature both Web and “desktop client” technology although it is possible that Web approach will be adopted more or less uniformly
Web 2.0 has a very active portal activity which has similar architecture to Grids • A page has multiple user interface fragments
Web 2.0 user interface integration is typically Client side using Gadgets AJAX and JavaScript while• Grids are in a special JSR168 portal server side using Portlets WSRP and Java
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The Ten areas covered by the 60 core WS-* Specifications
WS-* Specification Area Typical Grid/Web Service Examples
1: Core Service Model XML, WSDL, SOAP
2: Service Internet WS-Addressing, WS-MessageDelivery; Reliable Messaging WSRM; Efficient Messaging MOTM
3: Notification WS-Notification, WS-Eventing (Publish-Subscribe)
4: Workflow and Transactions BPEL, WS-Choreography, WS-Coordination
5: Security WS-Security, WS-Trust, WS-Federation, SAML, WS-SecureConversation
6: Service Discovery UDDI, WS-Discovery
7: System Metadata and State WSRF, WS-MetadataExchange, WS-Context
8: Management WSDM, WS-Management, WS-Transfer
9: Policy and Agreements WS-Policy, WS-Agreement
10: Portals and User Interfaces WSRP (Remote Portlets)
WS-* Areas and Web 2.0 WS-* Specification Area Web 2.0 Approach
1: Core Service Model XML becomes optional but still usefulSOAP becomes JSON RSS ATOM WSDL becomes REST with API as GET PUT etc.Axis becomes XmlHttpRequest
2: Service Internet No special QoS. Use JMS or equivalent?
3: Notification Hard with HTTP without polling– JMS perhaps?
4: Workflow and Transactions (no Transactions in Web 2.0)
Mashups, Google MapReduceScripting with PHP JavaScript ….
5: Security SSL, HTTP Authentication/Authorization, OpenID is Web 2.0 Single Sign on
6: Service Discovery http://www.programmableweb.com
7: System Metadata and State Processed by application – no system state – Microformats are a universal metadata approach
8: Management==Interaction WS-Transfer style Protocols GET PUT etc.
9: Policy and Agreements Service dependent. Processed by application
10: Portals and User Interfaces Start Pages, AJAX and Widgets(Netvibes) Gadgets
Drivers for Future Web 2.0 has momentum as it is driven by success of
social web sites and the user friendly protocols attracting many developers of mashups
Grids momentum driven by the success of eScience and the commercial web service thrusts largely aimed at Enterprise
We expect applications such as business and DoD where predictability and robustness important to be built on a Web Service (Narrow Grid) core with Web 2.0 functionality enhancements
Simplicity, supporting many developers are forces pressuring Grids!
Robustness and coping with unstructured blooming of a 1000 flowers are forces pressuring Web 2.0