this longer version

Grids for GeoSensors,

GeoScience and GeoScientists

PTLIU Laboratory for Community Grids

Geoffrey Fox

Computer Science, Informatics, Physics

Indiana University, Bloomington IN 4740

http://grids.ucs.indiana.edu/ptliupages/presentations/earthscopemar02

gcf@indiana.edu

Trends of Importance

n

Resources

of increasing performance or functionality

•

Computers (ASCI, Earth Simulator to TeraGrid),

storage, sensors, networks, PDA’s

n

Applications

of increasing sophistication

•

Size, multi-scales, multi-disciplines

n

New

algorithms

and mathematical techniques

n

Computer science

•

Compilers, Parallelism, Objects, Components

n

Grid

and

Internet

Concepts and Technologies

•

Enabling new applications

Projected Top 500 Until Year 2009

n

First, Tenth, 100th, 500th, SUM of all 500 Projected in Time

Earth Simulator from Japan

PACI 13.6 TF Linux TeraGrid

32 quad-processor McKinley

Servers Fibre Channel_Switch HPS S HPS S ESnet HSCC MREN/Abilene Starlight 10 GbE

NCSA

500 Nodes

8 TF, 4 TB Memory

240 TB disk

SDSC

256 Nodes

4.1 TF, 2 TB Memory

225 TB disk

Caltech

32 Nodes

0.5 TF

0.4 TB

Memory

86 TB disk

Argonne

64 Nodes

1 TF

0.25 TB

Memory

25 TB disk

= 32x 1GbE

= 64x Myrinet

= 32x FibreChannel

MyrinetClos

Spine Spine MyrinetClos Chicago & LA DTF Core Switch/Routers

Cisco 65xx Catalyst Switch (256 Gb/s Crossbar)

= 8x FibreChannel

OC-12 OC-12 OC-3 vBNS Abilene MREN Juniper M40

1176p IBM SP Blue Horizon OC-48 NTON 32 24 8 32 24 8 4 4 Sun E10K 4 1500p Origin UniTree 1024p IA-32 320p IA-64 2 14 8 Juniper M40 vBNS Abilene Calren ESnet OC-12 OC-12 OC-12 OC-3 8 Sun Starcat 16 GbE

= 32x Myrinet

HPS S 256p HP X-Class 128p HP V2500 92p IA-32 24 Extreme Black Diamond

32 quad-processor McKinley Servers (128p @ 4GF, 12GB

OC-12 ATM

Calren

Small Devices Increasing in Importance

n

There is growing

interest in wireless

portable displays in

the

confluence of cell

phone and personal

digital assistant

markets

n

By 2005,

60 million

internet ready cell

phones sold each

year

n

65%

of all

Broadband Internet

accesses via non

desktop

appliances

The HPCC Track

n

The

1990 HPCC 10 year initiative

was largely aimed at

enabling large scale simulations for a broad range of

computational science and engineering problems

n

It was in many ways a success and we have methods and

machines that can (begin to)

tackle most 3D simulations

•

ASCI simulations particularly impressive

•

DoE still putting substantial resources into basic software

and algorithms from adaptive meshes to PDE solver

libraries

n

Machines are still increasing in performance exponentially

and should achieve

petaflops

in next 7-10 years

n

EarthScope

community needs to harness these capabilities

•

Japan’s

Earth Simulator

activity major effort with large

Some HPCC Difficulties

n

An Intellectual failure

: we never produced a better

programming model than message passing

•

HPCC coding is hard work

•

Successes of ASCI software are like “Grid FTP” – not

parallelizing compilers

n

An institutional problem

: we do not have a way to produce

complex sustainable software for a niche (1%) market like

HPCC.

•

POOMA support just disappeared one day (foundation of

first proposal GEM wrote)

•

One must adopt commodity standards and produce

“small” sustainable modules.

•

Note distributed memory becoming dominant again with

HPCC Advice to EarthScope

n

KISS:

K

eep

i

t

Simple

and

Sustainable

n

Use

MPI

and

openMP

if needed for performance

on shared memory nodes

n

Adaptive Meshes

n

Load Balancing

n

PDE Solvers including

fast multipoles

n

Particle dynamics

n

Other areas such as datamining, visualization

and data assimilation quite advanced but still

significant research

}

Are well understoo

to get high performanc

parallel simulation

Use of Object Technologies I

n

The claimed commercial success in using

Object and

component technology

has not

yet

been a clear success in

HPCC

•

Object technologies

do not naturally support either

high performance or parallelism

•

C++

can be high performance but

Java (as a language)

is not uniformly so (it is improving)

•

Web Services

could change this

n

Fortran

(including Fortran90) will continue to decline in

importance and interest – the community should prefer

not to use it

•

It’s use will not attract the best students

n

Not essential

to write modules in

object oriented language

Use of Object Technologies II

n

There is

emerging HPCC component architecture

allowing

production of more modern libraries (integration

Infrastructure)

•

DoE has very large

CCA

– Common Component

Architecture – effort

•

Package software (“system and applications”)

as

distributed objects

– not as traditional libraries

n

CORBA Java

and

Web Services

are

not

naturally

high

performance as

component models

•

High performance

often

not essential

for

coarse grain

objects

•

Web Services

support multiple implementations

allowing

Application Structure

n

Earth Science applications

are typically scale and

multi-disciplinary

•

i.e. a given simulation is made of multiple components with

either different time/length scales and/or multiple authors

from possibly multiple fields

n

I am not aware of a systematic “Computational renormalization

group” – a methodology that links different scales together

n

However

composition of modules

is an area where (component)

technology of growing sophistication is becoming available

•

Needed commercially to integrate corporate functions

•

Easiest for large coarse grain components

•

Integration of data and simulation is one example of fine-scale

Object Size & Distributed/Parallel Simulations

n

All

interesting systems

consist of

linked entities

•

Particles, grid points, people or groups thereof

n

Linkage translates into

message passing

•

Cars on a freeway

•

Phone calls

•

Forces between particles

n

Amount of communication

tends to be proportional to

surface area of entity whereas simulation time proportional

to volume

n

So

communication/computation

is surface/volume and

decreases

in importance as

entity size increases

n

In parallel computing, communication synchronized; in

Some Problem Classes

n

Classic HPCC:

synchronized objects with regular time

structure (communication overhead decreases as

problem size increases)

•

Includes PDE and interacting particle based applications

•

Give

scaling parallelism on large MPP’s

n

Internet Technology and Commercial Application

Integration:

Large objects with modest communications

and without difficult time synchronization

•

Compose

as independent (pipelined)

services

•

Includes some approaches to multi-disciplinary simulation

linkage

n

Hardest:

smallish objects with irregular time

synchronization

What is a Grid or Web Service?

n

There are generic

Grid system services

: security, collaboration,

persistent storage, universal access

•

OGSA (Open Grid Service Architecture) is implementing these as

extended Web Services

n

An

Application Web Service

is a capability used either by another

service or by a user

•

It has input and output ports – data is from sensors or other

services

n

Consider

Satellite-based Sensor Operations

as a Web Service

•

Satellite management

(with a web front end)

•

Each

tracking station

is a service

•

Image Processing

is a pipeline of filters – which can be grouped

into different services

•

Data storage

is an important system service

•

Big services built hierarchically from “basic” services

Sensor Web Service

Distributed Sensor Web

Service

Out Web Service port

Universal sensor acces

for people/computers

In Web Service port

Application Web Services

n

Note Service model integrates sensors, sensor analysis, simulations and people

n

An

Application Web Service

is a capability used either by another service or

by a user

•

It has input and output ports – data is from users, sensors or other services

•

Big services built hierarchically from “basic” services

Sensor Data

as a We

service

(WS)

Data

Analysis

WS

Sensor

Managemen

WS

Visualization

WS

Simulation

WS

Filter

WS

Filter

WS

Filter

WS

Build as multiple Filter Web Services

Prog

WS

Prog

WS

The Application Service Model

n

As bandwidth of communication (between) services increases

one can support smaller services

n

A service “is a

component

” and is a replacement for a

library in case where performance allows

n

Services (components)

are a sustainable model of software

development – each service has documented capability with

standards compliant interfaces

•

XML

defines interfaces at several levels

•

WSDL

at Service interface level and

XSIL

or equivalent

for scientific data format

n

A service can be written as Perl, Python, Java Servlet,

Enterprise Javabean, CORBA (C++ or Fortran) Object …

n

Communication

protocol can be RMI (Java), IIOP

Services support Communities

n

Grid Communities

(Earth Science, SCEC, DoD, Earth

Science, High School Classes) are groups of

communicating individuals sharing resources

implemented as Web Services

n

Access Grid

from Argonne/NCSA is high-end

Audio/Video conferencing technology

n

Peer to Peer networking

describes a set of technologies

supporting community building with an emphasis on

less structured groups than classic “users of a

supercomputer”

n

Peer to peer Grids

combine the technologies and support

e-Science is just a pile of XML

n

Each leaf is a piece of XML either defining a nugget of

information and/or containing links to other XML or “raw

resources”

Biased History of Computing

n

In almost the beginning, there was

Fortran

and formats

(6I5, 5F10.4) for data

n

………..

n

1993-1997:

HTML

came along for Web Pages

n

1998-…:

XML

was developed to define information in

documents while HTML defining rendering

•

But soon it became used for specifying all data and their

format

n

2001:

Web Services

allowed XML to specify

methods

(subroutines) as well as data

n

Java, C++, Python, Perl, .. Fortran

are now “just” the

XML (RSS) Specification of Information Nuggets

n

<item rdf:about

="http://xml.com/pub/2000/08/09/xslt/xslt.html">

n

<title>

Processing Inclusions with XSLT

</title>

n

<link>

ht

tp://xml.com/pub/2000/08/09/xslt/xslt.html </

link>

n

<description>

n

Processing document inclusions with general XML tools can be

n

problematic. This article proposes a way of preserving inclusion

n

information through SAX-based processing.

n

</description>

n

</item>

n

<item rdf:about

="http://xml.com/pub/2000/08/09/rdfdb/index.html">

n

<title>

Putting RDF to Work

</title>

n

<link>

http://xml.

com/pub/2000/08/09/rdfdb/index.html </link>

n

<description>

n

Tool and API support for the Resource Description Framework

n

is slowly coming of age. Edd Dumbill takes a look at RDFDB,

n

one of the most exciting new RDF toolkits.

n

</description>

n

</item>

n

</rdf:RDF>

What is a Web Service I

n

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 XML (WSDL)

n

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

n

The simplest implementations involve

XML messages (SOAP)

and programs written in net friendly languages like Java and

Python

n

Web Services separate the

meaning of a port (message) interface

from its implementation

n

Enhances/Enables Re-usable component model of ANY

etc.

XML WS to WS Interfaces

(Virtual) XML Knowledge (User)

Interface

Clients

(Virtual) XML Data

Interface

Raw

Data

Ra

Resource

s

Raw

Data

W

S

W

S

Web Service

(WS)

W

S

W

S

W

S

W

S

W

S

W

S

Render to XML Display

Format

Classic Grid Architecture

Database

Database

Netsolv

e

Computin

g

Securit

y

Collaboratio

n

Compositio

n

Content

Access

Resources

Middle Tie

Brokers

Service

Providers

What is a Web Service II

n

Web Services have important implication that

ALL

interfaces are XML messages based.

In contrast

n

Most Windows programs have interfaces defined as

interrupts due to user inputs

n

Most software have interfaces defined as methods which

might be implemented as a message but this is often

NOT explicit

Securit

y

Catalo

g

Paymen

Credit

Card

Warehous

e

shipping

WSDL

What is a Web Service III

n

“Everything electronic” is a

resource

•

Computers; Programs; People

•

Data (from sensors to this presentation to email to

databases)

n

“Everything electronic” is a

distributed object

n

All

resources have interfaces

which are defined in

XML

for

both

properties

(data-structure) and

methods

(service,

function, subroutine) (

Resources

are

Services

)

•

We can assume that a data-structure property has

getproperty()

and

setproperty(value)

methods to act as

interface

n

All resources are linked by

messages

with structure, which

must be specifiable in XML

WSDL Abstractions

n

WSDL

abstracts a program

as an entity that does

something given one or more inputs with its results

defined by streams on one or more outputs.

n

Functions are defined by method name and

parameter

methodname(parm1,parm2, … parmN)

•

Where parameters are “Input” “Output” or both

n

In WSDL, we will have a

Web Service

which like a

(Java or CORBA Program) can be thought of as a

(distributed) object with many methods

•

Instead of a function call, the “calling routine” sends an

XML message to the Web Service specifying

methodname

and values of the parameters

Details of WSDL Protocol Stack

n

UDDI

finds where programs are

•

remote( (distributed) programs

are just Web Services

n

WSFL

links programs togethe

(under revision?)

n

WSDL

defines interface (methods,

parameters, data formats)

n

SOAP

defines structure of message

including serialization of information

n

HTTP

is negotiation/transport

protocol

n

TCP/IP

is layers 3-4 of OSI

n

Physical Network

is layer 1 of OSI

UDDI or WSIL

WSFL

WSDL

SOAP or RMI

HTTP or SMTP

or IIOP or RMTP

TCP/IP

Examples of Web Services I

n

OGSA (Open Grid Service Architecture)

•

Integrate Web Service and Grid Concepts and allows Globus

to be implemented as Web Services

n

Audio-Video Conferencing

as a Web Service

•

Integrates H323, SIP, JXTA (etc.) protocols by mapping to

single XML Interface

•

Provides VRVS reflector model from Messaging Web Service

n

Messaging or Event Web Service

provides intelligent routing

and buffering of messages

n

Computing

as a Web service

•

Job submittal, status, composition, data services, visualization

•

Performance WS

allows access to distributed monitoring

Examples of Web Services II

n

Education

as a Web Service

•

One of easiest to do as object standards well defined (IMS)

and little performance issues

•

Grading, Homework submission, registration, assessment etc.

n

Universal Access

and Web Services

•

As Web Services allow multiple implementation of a

particular interface, one can adjust to needs of particular

clients (PDA v. versus, impaired sight etc.)

•

Can build custom implementations of certain web services for

particular communities but re-use others

n

Collaborative Web Services

•

As interfaces all message based,

much easier to share Web

Education as a Web Service

n

Can link to Science as a Web Service and substitute educational

modules

n

“

Learning Object

” XML standards already exist from IMS/ADL

h

ttp://www.adlnet.org –

need to update architecture

n

Web Services for

virtual university

include:

n

Registration

n

Performance

(grading)

n

Authoring

of Curriculum

n

Online laboratories

for real and virtual instruments

n

Homework submission

n

Quizzes

of various types (multiple choice, random parameters)

n

Assessment

data access and analysis

n

Synchronous Delivery

of Curricula

n

Scheduling

of courses and mentoring sessions

Distributed Information

Actually the XML is

distributed

Structured (XML) Information

earthscope://root/one/two/botto

m

roo

t

one

two

bottom

Note XML specifie

both internal an

Matching Information/Service

Providers and Consumers I

n

Classic Centralized Approach

n

Those with services

publish information

as to location –

this is percolated

up and down the tree of brokers

n

At simplest, publish location; better publish location

and meta-data allowing easier discovery of value

n

Those wanting service, look it up using either

•

Some search of information registered with brokers

•

A search using a system like Google

•

Because they were told some key

n

Like using an

encyclopedia

; very

reliable

and

fast for

Unstructured and Structured XML

earthscope://root/one/two/mes

s

roo

t

one

two

mess

“mess” can be multiple levels of tree

Hoosier National Forest showin

Peer to Peer Grid

Database

Database

JXTA

JXTA

Web Service Interfaces

Web Service Interfaces

Event

Messag

Brokers

Integrate P2P

and Grid/WS

Matching Information/Service

Providers and Consumers II

n

Peer-to-peer Approach (or how to search the “mess”)

n

Those with services

publish XML advertisements to their

friends

; their friends

may

forward it to other friends

n

Those wanting a service, publish an XML request to a chosen set

of friends

n

Friends use their

personal idiosyncratic approach

to matching

requests with advertisements and to choosing who else should be

asked

n

Analogous to way

communities exchange information

as in a

meeting like this

n

Uncertain reliability but

scales well

(communities intra-exchange

Message

Or Event

Based

Inte

Connection

Reso

urce

Data

base

Reso

urce

Sof

ware

Sof

ware

XM

Skin

e-Science is XML Specified Resource

connected by XML specified messages

XM

Skin

Technology Trends and Principles

n

All performance and capability measures of infrastructure

continue to improve

n

Gilder’s law

says that network bandwidth increases 3 times

faster than CPU Performance (

Moore’s Law

)

n

The

Telecosm

eclipses the

Microcosm

(but don’t look at Wall

Street) ….

George Gilder

Telecosm : How Infinite

Bandwidth Will

Revolutionize Our World

(September 2000, Free

Press; ISBN:

Grid/P2P Use of Internet I

ROBERT B. COHEN, PH.D.

COHEN COMMUNICATIONS GROUP

Cohen’s

Rival Estimate

Mainl

Grid/P2P Use of Internet II

S2S Server to Server

Meta-Data and Web Services

n

Enriching resources with meta-data is critical idea

•

Enables one to identify and link resources around the globe

•

Allows one to find out “meaning” of a Web service not just

syntax of interface

n

Semantic Grid

implies linkage of Grid/Web services

enabled by meta-data leading to “

digital brilliance

”

phase transition

n

We can experiment with Semantic Web techniques for

specifying meta-data

RDF DAML OIL

n

These encompass both straightforward enriched data

Semantic Grid & Digital Brilliance I

n

The (XML) advertisement-request matching provides a

publish-subscribe linkage

between resources – these are

people, computers and raw/processed data

n

The richer the meta-data, the more precise the linkage

•

This is spirit of

Semantic Web

– RDF/DAML/OIL

metadata enables meaningful linkage

n

In a physics analogy,

resources

can be thought of as

spins

and the

meta-data

induced linkage as

interactions

n

Phase transitions

will occur when “enough” resources

are linked – one will get associated spins to align in the

direction of

new knowledge

Semantic Grid & Digital Brilliance II

n

This suggests ways of quantifying value of

metadata

induced linkages

and ways of identifying where one

“should” add more resource specifications

n

Note that related

resources

are

not

necessarily

directly

connected

but rather messages are forwarded through

friends

n

Study of Peer to Peer

networks teach us that we can

build “

small worlds

” where distance between resources

is logarithmic in number of nodes

n

This physics based picture provides an interesting

underlying formalism to give a

theory of e-Science

….

•

All you need to do is to

build

a

lot

of

XML Meta-data

Semantic Grid & Digital Brilliance III

n

EarthScope Collaboratory

consists of a set of connected “spins”

(being a physicist; resources if I was W3C)

n

Resources are anything with a digital signature

•

Raw data, Analysers, Simulators, Simulations, Processed

Information, Extracted Knowledge, Scientists ….

n

The linkage of

Earthquake Fault Simulator Web Service

to the

Greens Function Solver Web Service

is as program to

subroutine; must have

agreement

on both

syntax

and

Semantics

n

The linkage of

Granular Physics model

to (my) remark that Los

Alamos has interesting

new simulation technology

is

less precise

n

So linkages with very precise ontologies and those which are

Web (Unstructured) mode for Google

Portals and Web Services

n

Web Services

allow us to build a

component model

(see

CCA) for resources.

n

Each resource

naturally has a

user interface

(which

might be customized for user)

n

Web Service <--> Portlet

n

Natural to use a component model for portal building

displayed web page from collection of portlets

•

So can customize each portlet and customize which portlets

you want

n

Apache Jetspeed

seems good open source technology

supporting this model

•

JSP model

is better than say a client-side Java integration in

Jetspeed Computing Portal: Choose Portlets

4 available portlet

Choose Portlet Layout

Choose 1-column Layout

Online Knowledge Center for DoD HPCMO

n

Web Services

provide a

component model

for the

middleware (see large “

common component

architecture

” effort in Dept. of Energy)

n

Should match each WSDL component with a

corresponding user interface component

n

Thus one “must use” a

component model for the portal

with again an XML specification (

portalML

) of portal

EarthScope CSIT Strategy

n

Make a list of

resources

with a hierarchical

arrangement

•

People, Places, Results (Publications, meeting archives,

Simulation Output), Activities, Sensors (Instruments), Data

(raw and processed), Earth features, Computers, Software

n

Decide on component (Web Service) model and

URI

labelling (

earthscope://devices/satellites/year/label

…)

•

Respect

performance

requirements

•

Design so modules can be re-used, re-arranged and replaced

for outreach (

education

)

n

Study related CSIT architectures of other fields

•

Grid Forum, PACI, ASCI for

computing issues

•

W3C Web Consortium for

basic IT infrastructure

•

openGIS XMML for

related fields

EarthScope HPCC Strategy

n

Decide what services are well enough understood and useful

enough to be encapsulated as

application Web Services

•

Parallel FEM Solvers

•

Visualization

•

Parallel Particle Dynamics

•

Access to Sensor Data

•

Image Processing

n

Make services as

small

as possible – smaller is simpler and more

sustainable but with higher communication needs

•

Compose large services from smaller ones

n

Design

Portals

and portal components that allow one to

manipulate services –

set parameters, compose, invoke

n

Implement chosen System Web Services (job submit,

performance, queue) on

central machines

and

local clusters

•

Make certain infrastructure supports compute, data,

middleware needs

EarthScope IT Strategy

n

Design an internal

EIF

(EarthScope Internal

Framework) defining architecture and interface

standards of internal Web Services and data structures

n

Design

EEF

(EarthScope External Framework) which

maps external raw data into sensor web services

n

Choose some appropriate (mix of)

middleware

frameworks

•

.net, IBM, BEA, Sun, Oracle

n

Look at special requirements for key

system services

•

Hardware/Data systems

(new and legacy issues)

•

Security

•

Collaboration

including Audio/Video conferencing

•

Peer-to-peer

networking

EarthScope Peer to Peer Grid Community

Gateway and Web Services

n

We will use the Gateway Computing Portal as an

example (

http://www.gatewayportal.org)

•

It is largely built using CORBA with a Java Server Pages

front end

•

http://community.ucs.indiana.edu:8004/GCWS/BatchScriptGen/Main.jsp

n

Se

veral capabilities have been interfaced using WSDL

•

Job Submission

(11 Methods including execute local and

remote command, copy files etc. as well as Submit Job)

•

Manage WebFlow Session

(67 Methods)

•

Generate Batch Script

(just 1 method but two

implementations developed – one at SDSC and one at Indiana

– with

UDDI

to manage)

•

Each is one service – could have used finer grain services

•

Sample files are a

Gateway Architecture

n

As needed DoD approved Kerberos/SecureID security,

does not usually link to standard Grid technology (Globus)

backen

d

Globu

or submit to loca

queue system

Corba middle tie

SECIOP wit

Java modules

JSP SSL

backen

d

SOAP wrappe

JSP Servlet

CORBA

WSDL

Will replac

historical CORBA

By EJB

Add Casto

Java to XML

SOAP and Gateway Portal I

n

Having specified service in WSDL, the run-time is

implemented in SOAP which is “just” an XML header

(info needed by transport – empty here) and body

n

Here is SOAP transported by HTTP message

n

This is

execLocalCommand

WSDL operation to run

one particular command (

ls

) on current WebFlow

directory

Argument of operation

n

And this is the result of

ls

sent back to client in

SOAP

over

HTTP

SOAP and Gateway

Portal II

HTTP

Header

SOA

WSDL Message Example

<message name="submitRequest">

<part name="

xmljob

" type="

xsd:string

"/>

</message>

<message name="submitResponse">

<part name="

response

" type="

xsd:string

"/>

</message>

For the batch script service, we pass the XML description

of the job as a string and get back the script as a string.

In general, any XML primitive or complex types can be

used in messages.

WSDL portTypes Example

<portType name="

BatchScriptServicePortType

">

<operation name="

batchGen

">

<output message="

tns:submitResponse

"

name="

submitResponse

"/>

<input message="

tns:submitRequest

"

name="

submitRequest

"/>

</operation>

</portType>

WSDL SOAP Binding Example

<binding name="BatchBinding" type="tns:BatchScriptServicePortType">

<soap:binding style="

rpc

"

transport="

http://schemas.xmlsoap.org/soap/http

"/>

<operation name="

batchGen

">

<soap:operation soapAction=""/>

<input>

<soap:body use="

encoded

“ namespace="

urn:BatchScriptService

"

encodingStyle="

http://schemas.xmlsoap.org/soap/encoding/

"/>

</input>

<output>

<soap:body use="

encoded

" namespace="

urn:BatchScriptService

“

encodingStyle="

http://schemas.xmlsoap.org/soap/encoding/

"/>

</output>

</operation>

WSDL Ports and Services

<service name="

BatchScriptService

">

<documentation>

BS stands for Batch Script

</documentation>

<port binding="

BatchBinding

”

name="

BatchPort

">

<soap:address location=

"

http://yourserver/soap/servlet/rpcrouter/

"/>

</port>

</service>

</definitions>

ports

portType

_binding

are concrete implementations of

_{(by name).}

s and point back to a particular

They also point to the specific location of a

server that implements the service.

What is a Virtual XML Interface

n

We can

specify interfaces in XML

but we are

not

required to

implement in XML

.

n

Example 1:We aren’t likely to change syntax of mai

Reply-to:

Geoffrey Fox <gcf

@indiana.edu

To: Ge

offrey Fox <gcf@g

rids.ucs.indiana.edu

Subjec

t:

A Test for Tutoria

A simple mail messag

Geoffrey Fox gcf@indiana.edu FAX 812856797

Phones Cell 315-254-6387 Home 812323919

n

But we could specify and indeed store in XML with transport

done using conventional SMTP.

n

So conventional mail is easy to give a

virtual XML

specification

for wit

name:

value

becomin

Mail in XML

n

<mailasxml

uri=“

gxos://mail/users/gcf/sent/2002/february/290

”

<smtpheaders

<reply-to email=“

gcf@

indiana.edu” >Ge

offrey Fox

</reply-to>

<to email=“

gcf@g

rids.ucs.indiana.edu” >Geo

ffrey Fox

</to>

<subject>

A Test for Tutorial

</subject

</smtpheaders

<smtpbody>

<message whitespace="

collapse

">

A simple mail

message

</message>

<signature personuri=“

ssn://123/45/6789

” whitespace=“

preserve

” >

Geoffrey Fox gcf@indiana.edu FAX 812856797

Phones Cell 315-254-6387 Home 812323919

</signature>

</smtpbody

</mailasxml>

n

Such an interface could be used by “User Messaging as a Web service” which