1
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
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
3
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
4
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
Not so controversial Ideas
n Distributed software systems are being “revolutionized” bydevelopments 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
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
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
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
9
“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
Web 2.0 Systems are Portals, Services, Resources
n
Captures the incredible development of interactive
11
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”
12
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
13
Web 2.0 uses all types of Services
n
Here a Gadget Mashup uses a 3 service workflow with
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
”
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
APIs/Mashups per Protocol
Distribution
REST SOAP XML-RPC REST,
XML-RPC XML-RPC,REST, SOAP
REST,
SOAP JS Other
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
18
Mash
Planet
Web 2.0
Architecture http://www.imagin
19
20
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
21
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)
Now to Portals
22
Grid-style portal as used in Earthquake Grid
23
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!
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
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
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
Web 2.0 v Narrow Grid III
n Narrow Grids have a strong emphasis on standards andstructure; 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
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
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
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
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