Web 2 0 in a Web Services and Grid Context Part I: CTS2007 Web 2 0 Tutorial

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Web 2.0 in a Web Services and

Grid Contex

Part I: CTS2007 Web 2.0 Tutorial

CTS 2007

Embassy Suites Hotel-Lake Buena Vista Resort, Orlando, FL, USA May 25 2007

Geoffrey Fox and Marlon Pierce

Computer Science, Informatics, Physics Pervasive Technology Laboratories Indiana University Bloomington IN 47401

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Applications, Infrastructure,

Technologies

n

This field is confused by inconsistent use of terminology

– this is what I mean

n

Web Services

,

Grids

and

Web 2.0

(

Enterprise 2.0

) are

technologies

n

These technologies combine and compete to build

electronic infrastructures

termed

e-infrastructure

or

Cyberinfrastructure

n

e-moreorlessanything

is an emerging application area

of broad importance that is hosted on the

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e-moreorlessanything is the Application

n ‘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

n Similarly e-Business captures an emerging view of corporations as

dynamic virtual organizations linking employees, customers and stakeholders across the world.

n Net Centric computing is a similar DoD vision n This generalizes to e-moreorlessanything

n A deluge of data of unprecedented and inevitable size must be

managed and understood.

n People (see Web 2.0), computers, data and instruments must be

linked.

n On demand assignment of experts, computers, networks and

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Role of Electronic infrastructure

n 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)

n Exploits Internet technology (Web2.0) adding (via Grid

technology) management, security, supercomputers etc.

n It has two aspects: parallel – low latency (microseconds)

between nodes and distributed – highish latency (milliseconds) between nodes

n Parallel needed to get high performance on individual 3D

simulations, data analysis etc.

n Distributed aspect integrates already distinct components

n Electronic infrastructure is in general a distributed collection

of parallel systems and presented as services (often Web

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Not so controversial Ideas

n 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”

n 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

n Currently Grids are built using Web Services with possible

enhancements like WSRF which we call Narrow or Web service Grids

n We expect that future systems will be built as Broad Grids which

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Web 2.0 and Web Services I

n 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.

n “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)

n 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

n Web 2.0 also has many well known capabilities with Google

Maps and Amazon Compute/Storage services of clear general relevance

n There are also Web 2.0 services supporting novel collaboration

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Web 2.0 and Web Services II

n

I once thought

Web Services

were

inevitable

but this is

no longer clear to me

n

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

n

There are

de facto standards

like

Google Maps

and

powerful suppliers like Google which “define the rules”

n

One can easily

combine SOAP

(Web Service) based

services/systems with HTTP messages but the “lowest

common denominator” suggests additional

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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_websitesWritely, Wikis and Blogs are powerful specialized shared

document systems

ConferenceXP and WebEx share general applicationsGoogle 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

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“Best Web 2.0 Sites” -- 2006

n

Extracted from

http://web2.wsj2.com/

n

Social Networking

n

Start Pages

n

Social Bookmarkin

n

Peer Production News

n

Social Media Sharing

n

Online Storage

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Web 2.0 Systems are Portals, Services, Resources

n

Captures the incredible development of interactive

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Mashups v Workflow?

n Mashup Tools are reviewed at http://blogs.zdnet.com/Hinchcliffe/?p=63 n Workflow Tools are reviewed by Gannon and Fox

http://grids.ucs.indiana.edu/ptliupages/publications/Workflow-overview.pdf

n Both include

scripting in PHP, Python, sh etc. as both implement distributed

programming at level of services

n Mashups use all

types of service

interfaces and do not have the potential

robustness (security) of Grid service

approach

n Typically “pure”

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Grid Workflow Datamining in Earth Science

n Work with Scripps Institute

n Grid services controlled by workflow process real time

data from ~70 GPS Sensors in Southern California

Streaming Data Support

Transformations Data Checking

Hidden Marko Datamining (JPL)

Display (GIS)

NASA GPS

Earthquake

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Web 2.0 uses all types of Services

n

Here a Gadget Mashup uses a 3 service workflow with

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Web 2.0 APIs

http://www.programmable

web.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

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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

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APIs/Mashups per Protocol

Distribution

REST SOAP XML-RPC REST,

XML-RPC XML-RPC,REST, SOAP

REST,

SOAP JS Other

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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, games

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Mash

Planet

Web 2.0

Architecture http://www.imagin

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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

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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)

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Now to Portals

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Grid-style portal as used in Earthquake Grid

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Portlets v. Google Gadgets

n

Portals for Grid Systems are built using portlets with

software like GridSphere integrating these on the

server-side into a single web-page

n

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

n

Google is more user friendly!

n

The many Web 2.0 competitions is an interesting model

for promoting development in the world-wide

distributed collection of Web 2.0 developers

n

I guess Web 2.0 model will win!

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Typical Google Gadget Structure

… Lots of HTML and JavaScript </Content> </Module>

Portlets build User Interfaces by combining fragments in a standalone Java Server

Google Gadgets build User Interfaces by combining fragments with JavaScript on the client

Google Gadgets are an example of Start Page technolog

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Web 2.0 v Narrow Grid I

n 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

n Web 2.0 chooses simplicity (REST rather than SOAP) to lower

barrier to everyone participating

n 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

n Web 2.0 and Grids both use SOA Service Oriented Architectures n “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 Grids

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Web 2.0 v Narrow Grid III

n 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 reasoningAnnotation in sites like del.icio.us and uploading to

MySpace/YouTube is unstructured and free text search replaces structured ontologies

n 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

n Web 2.0 has a very active portal activity which has similar architecture to

Grids

A page has multiple user interface fragments

n 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

WSRP (Remote Portlets) 10: Portals and User

Interfaces

WS-Policy, WS-Agreement 9: Policy and Agreements

WSDM, WS-Management, WS-Transfer 8: Management

WSRF, WS-MetadataExchange, WS-Context 7: System Metadata and State

UDDI, WS-Discovery 6: Service Discovery

WS-Security, WS-Trust, WS-Federation, SAML, WS-SecureConversation

5: Security

BPEL, WS-Choreography, WS-Coordination 4: Workflow and

Transactions

WS-Notification, WS-Eventing (Publish-Subscribe)

3: Notification

WS-Addressing, WS-MessageDelivery; Reliable Messaging WSRM; Efficient Messaging MOTM 2: Service Internet

XML, WSDL, SOAP 1: Core Service Model

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WS-* Areas and Web 2.0

Start Pages, AJAX and Widgets(Netvibes) Gadgets 10: Portals and User

Interfaces

Service dependent. Processed by application 9: Policy and Agreements

WS-Transfer style Protocols GET PUT etc. 8:

Management==Interaction

Processed by application – no system state –

Microformats are a universal metadata approach 7: System Metadata and

State

http://www.programmableweb.com 6: Service Discovery

SSL, HTTP Authentication/Authorization, OpenID is Web 2.0 Single Sign on

5: Security

Mashups, Google MapReduce

Scripting with PHP JavaScript …. 4: Workflow and

Transactions (no

Transactions in Web 2.0)

Hard with HTTP without polling– JMS perhaps? 3: Notification

No special QoS. Use JMS or equivalent? 2: Service Internet

XML becomes optional but still useful SOAP becomes JSON RSS ATOM

WSDL becomes REST with API as GET PUT etc. Axis becomes XmlHttpRequest

1: Core Service Model

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Drivers for Future

n

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

n

Grids momentum

driven by the success of

eScience

and

the

commercial web service

thrusts largely aimed at

Enterprise

n

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

n

Simplicity

,

supporting many developers

are forces

pressuring Grids!

n

Robustness

and coping with

unstructured blooming of

Figure

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References

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