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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

gcf@indiana.eduhttp://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