Building Web Portals as Science Gateways

Marlon Piercempierce@cs.indiana.edu

with slides from Dennis Gannon, Ahmet Sayar, Galip Aydin

Indiana University

Marlon Piercempierce@cs.indiana.edu

with slides from Dennis Gannon, Ahmet Sayar, Galip Aydin

Indiana University

Outline of Talk• Overview of computing portals as gateways to

cyberinfrastructure.– With several example projects

• Architectures and standards of computing portals.– Review of portal architectures– Review of JSR168

• Building science portals.– With a motivating example

• New technologies and techniques– JSF– AJAX

• Overview of computing portals as gateways to cyberinfrastructure.– With several example projects

• Architectures and standards of computing portals.– Review of portal architectures– Review of JSR168

• Building science portals.– With a motivating example

• New technologies and techniques– JSF– AJAX

Computing for the Greater Good

• Recent devastating natural disasters have demonstrated the need for large scale, distributed scientific computing.– Katrina, Rita, …– Christmas 2004 tsunamis– Earthquakes in Pakistan and future major

earthquakes in California, Japan, …• 1906 was 99 years ago…

• Research in large scale distributed computing can make a difference in people’s lives.

• But many challenges lie ahead.

• Recent devastating natural disasters have demonstrated the need for large scale, distributed scientific computing.– Katrina, Rita, …– Christmas 2004 tsunamis– Earthquakes in Pakistan and future major

earthquakes in California, Japan, …• 1906 was 99 years ago…

• Research in large scale distributed computing can make a difference in people’s lives.

• But many challenges lie ahead.

Cyberinfrastructure (CI) Overview• Cyberinfrasture combines

– Grid computing: • Globus toolkit, Storage Resource Broker, Condor, UK OMII, OGSA-

DAI, etc.• Provides the software for tying together distributed computing

resources– High speed networking– Hardware: supercomputers, clusters, workstations– Applications: modeling, simulation, data analysis codes in many

fields.– Data: raw, cooked, shared, derived, cataloged, etc.– Information/Internet Technology: web services, portals,

databases, XML, semantic web/grid, audio/video collaboration, shared Web spaces, etc.

– People• Cyberinfrastructure is supposed to enable remote collaborations

and distributed teams.• This is the reality of a lot of science (and science funding)

• Cyberinfrasture combines– Grid computing:

• Globus toolkit, Storage Resource Broker, Condor, UK OMII, OGSA-DAI, etc.

• Provides the software for tying together distributed computing resources

– High speed networking– Hardware: supercomputers, clusters, workstations– Applications: modeling, simulation, data analysis codes in many

fields.– Data: raw, cooked, shared, derived, cataloged, etc.– Information/Internet Technology: web services, portals,

databases, XML, semantic web/grid, audio/video collaboration, shared Web spaces, etc.

– People• Cyberinfrastructure is supposed to enable remote collaborations

and distributed teams.• This is the reality of a lot of science (and science funding)

Scientific Challenges• The current and future

generations of scientific problems are:– Data Oriented (CI challenge)

• Increasingly stream based.• Often need petabyte archives• But linking data to applications

across groups is a general problem.

– In need of on-demand computing resources (CI challenge)

– Conducted by geographically distributed teams of specialists

• Who don’t want to become experts in grid computing.

• The current and future generations of scientific problems are:– Data Oriented (CI challenge)

• Increasingly stream based.• Often need petabyte archives• But linking data to applications

across groups is a general problem.

– In need of on-demand computing resources (CI challenge)

– Conducted by geographically distributed teams of specialists

• Who don’t want to become experts in grid computing.

Science Communities and Outreach

• Communities• CERN’s Large Hadron Collider

experiments• Physicists working in HEP and

similarly data intensive scientificdisciplines

• National collaborators and thoseacross the digital divide indisadvantaged countries

• Scope• Interoperation between LHC

Data Grid Hierarchy and ETF• Create and Deploy Scientific

Data and Services Grid Portals• Bring the Power of ETF to bear

on LHC Physics Analysis: Helpdiscover the Higgs Boson!

• Partners• Caltech• University of Florida• Open Science Grid and Grid3• Fermilab• DOE PPDG• CERN• NSF GriPhyn and iVDGL• EU LCG and EGEE• Brazil (UERJ,…)• Pakistan (NUST,…)• Korea (KAIST,…)

LHC Data Distribution Model

Identify Genes

Phenotype 1 Phenotype 2 Phenotype 3 Phenotype 4

Predictive Disease Susceptibility

Physiology

Metabolism Endocrine

Proteome

Immune Transcriptome

BiomarkerSignatures

Morphometrics

Pharmacokinetics

EthnicityEnvironment

AgeGender

Genetics and Disease Susceptibility

Source: Terry Magnuson, UNC

On-DemandStorm predictions

StreamingObservations

Forecast Model

Data Mining

Storms Forming

Science Web Portals The goals of a Science Web Portal are

– To give a community of researchers easy access to • Computational applications and tools • Primary data, shared data, derived data• Computational resources• All are needed to solve today’s scientific and engineering

problems.

– To do this in a discipline specific language that is common to the target community.

• Science Portals are “gateways” to underlying Grid tools– Grids provide access to computing resources– Gateways manage the user’s interaction with the grid.

The goals of a Science Web Portal are– To give a community of researchers easy access to

• Computational applications and tools • Primary data, shared data, derived data• Computational resources• All are needed to solve today’s scientific and engineering

problems.

– To do this in a discipline specific language that is common to the target community.

• Science Portals are “gateways” to underlying Grid tools– Grids provide access to computing resources– Gateways manage the user’s interaction with the grid.

What is a Science Portal?• A standards-based web portal

– Provides each user with • a secure way to login and authenticate identity• A view of a private workspace for accessing and

managing data and tools

• Tutorials and community news– Announcements of new services

• Collaboration tools– Chat, calendaring, group messaging

• Core Science Functions …

• A standards-based web portal– Provides each user with

• a secure way to login and authenticate identity• A view of a private workspace for accessing and

managing data and tools

• Tutorials and community news– Announcements of new services

• Collaboration tools– Chat, calendaring, group messaging

• Core Science Functions …

Portal Science Capabilities• Data Access is the most important

– Allow the user community access to important shared data resources

• Visualize it, publish it, download it, curate it.– Data Discovery

• Searchable metadata directories.

• Web access to important tools– Web-form interfaces to allow users to run important

community codes– Webstart access to common java-based tools

• Workflow tools– Allow users to combine community codes into

workflows managed by the portal back-end resources.

• Data Access is the most important– Allow the user community access to important shared

data resources• Visualize it, publish it, download it, curate it.

– Data Discovery• Searchable metadata directories.

• Web access to important tools– Web-form interfaces to allow users to run important

community codes– Webstart access to common java-based tools

• Workflow tools– Allow users to combine community codes into

workflows managed by the portal back-end resources.

Let’s look at a few real examples

(about a dozen … many more exist!)

(about a dozen … many more exist!)

ServoGrid Portal

NEESGridRealtime access to earthquake Shake table experiments at remote sites.

Geological Information Grid Portal

Mesoscale MeteorologyNSF LEAD project - making the tools thatare needed to make accurate predictions of tornados and hurricanes. - Data exploration and Grid workflow

Renci Bio PortalProviding access to biotechnology tools running on a back-end Grid.

- leverage state-wide investment in bioinformatics- undergraduate & graduate education, faculty research- another portal soon: national evolutionary synthesis center

SCOOP ADCIRC Interface

• SURA SCOOP– Southeastern Coastal Ocean Observing Program

• Advanced Circulation Model (ADCIRC)– Finite Element Hydraulic Model for Coastal Areas, Inlets and Rivers

• Rick Luettich (UNC), Joannes Westerink (Notre Dame)• Randall Kolar (Oklahoma), Clint Dawson (Texas), Corps of Engineers

• Collaborators:– Leuttich/Blanton (UNC Marine Sciences)– Ramakrishnan/Lander (RENCI)

• SURA SCOOP– Southeastern Coastal Ocean Observing Program

• Advanced Circulation Model (ADCIRC)– Finite Element Hydraulic Model for Coastal Areas, Inlets and Rivers

• Rick Luettich (UNC), Joannes Westerink (Notre Dame)• Randall Kolar (Oklahoma), Clint Dawson (Texas), Corps of Engineers

• Collaborators:– Leuttich/Blanton (UNC Marine Sciences)– Ramakrishnan/Lander (RENCI)

Current ADCIRC gridDecomposition

Set Run Dates

Submit Job

To GRID Katrina Storm Surge Prediction(Leuttich/Blanton)

X-Ray Crystallography

Flood Modeling

Large-scale flooding along Brays Bayou in central Houston triggered by heavy rainfall during Tropical Storm Allison (June 9, 2001) caused more than $2 billion of damage.

•University of Texas•TACC•Center for Research in Water Resources

•ORNL•Purdue

Gordon Wells, UT; David Maidment, UT; Budhu Bhaduri, ORNL, Gilbert Rochon, Purdue

Teragrid Gateway Portals• TeraGrid

–The largest “public” super-computing grid in the US.• 50 TFlops

–Massive Data storage capability• Over 1 Petabyte on-line storage

• TeraGrid Gateways–Access points for communities.–Two types:

• A gateway between 2 grids– Open Science Grid gate way is one example.

–Science Community Portal is the other type • Includes LEAD portal, Nanohub, Renci Bioportal, NVO

• An additional set of new science portals just being developed.

• TeraGrid–The largest “public” super-

computing grid in the US.• 50 TFlops

–Massive Data storage capability• Over 1 Petabyte on-line storage

• TeraGrid Gateways–Access points for communities.–Two types:

• A gateway between 2 grids– Open Science Grid gate way is one example.

–Science Community Portal is the other type • Includes LEAD portal, Nanohub, Renci Bioportal, NVO

• An additional set of new science portals just being developed.

The Portal as a Service Framework

• Many important science portals are designed to access and orchestrate stand-alone web services and databases

• Others are service frameworks that sit on top of an existing Grid, such as TeraGrid.

• In both cases:– The architecture is similar– Common portal services are often shared

• A Common architecture is emerging

• Many important science portals are designed to access and orchestrate stand-alone web services and databases

• Others are service frameworks that sit on top of an existing Grid, such as TeraGrid.

• In both cases:– The architecture is similar– Common portal services are often shared

• A Common architecture is emerging

The Architecture of Gateway ServicesThe Users Desktop.The Users Desktop.

Gateway Services

Grid Portal Server

Grid Portal Server

Physical Resource Layer

Core Grid Services

Proxy CertificateServer / vault

Proxy CertificateServer / vault

Application EventsApplication EventsResource BrokerResource Broker

User MetadataCatalog

User MetadataCatalog

Replica MgmtReplica Mgmt

ApplicationWorkflow

ApplicationWorkflow

App. Resourcecatalogs

App. Resourcecatalogs

ApplicationDeployment

ApplicationDeployment

ExecutionManagement

ExecutionManagement

InformationServices

InformationServices

SelfManagement

SelfManagement

DataServices

DataServices

ResourceManagement

ResourceManagement

SecurityServicesSecurityServices

OGSA-like Layer

Next Steps

• Many components of this architecture are now shared between different portal groups.

• We now look at some of the technology behind these portals.

• Many components of this architecture are now shared between different portal groups.

• We now look at some of the technology behind these portals.

A Portal Architecture A Portal Architecture ReviewReview

A Famous Web PortalA Famous Web Portal

A Famous Portal, After LoginA Famous Portal, After Login

What to NoticeWhat to Notice After logging in, my colors, layouts, and After logging in, my colors, layouts, and

content all changed.content all changed.• I get my stock list, my Bloomington weather, my I get my stock list, my Bloomington weather, my

news stories, etc.news stories, etc.• I got rid of “Garfield”I got rid of “Garfield”

As we will see later, each of these content As we will see later, each of these content fragments (encircled) is managed by a thing fragments (encircled) is managed by a thing called a called a portletportlet……• … … I don’t guarantee that this is true for Yahoo’s I don’t guarantee that this is true for Yahoo’s

web site but it is true for a large class of web site but it is true for a large class of enterprise Java portal systems.enterprise Java portal systems.

Portlets are the key to portal software reuse.Portlets are the key to portal software reuse.

Let 10,000 Flowers BloomLet 10,000 Flowers Bloom Many portal projects have been launched Many portal projects have been launched

since late ’90s. since late ’90s. • First Generation: HotPage from SDSC, NCSA First Generation: HotPage from SDSC, NCSA

efforts, DOD, DOE Portals, NASA IPGefforts, DOD, DOE Portals, NASA IPG• 2002 Special Issue of 2002 Special Issue of Concurrency and Concurrency and

Computation: Practice and ExperienceComputation: Practice and Experience.. The field continues to be activeThe field continues to be active

• Global Grid Forum 14 Science Gateway workshop Global Grid Forum 14 Science Gateway workshop in June 2005.in June 2005.

• About 15 gateways will be described in upcoming About 15 gateways will be described in upcoming issue of issue of Concurrency.Concurrency.

• GCE2005 workshopGCE2005 workshop at Supercomputing 05. at Supercomputing 05. How do we share and reuse all of this work?How do we share and reuse all of this work?

Por

tal U

ser

Inte

rfac

e Grid ResourceBroker Service

Grid and Web

Protocols

Informationand

Data Services

DatabaseService Database

HPCor

Compute Cluster

Grid InformationServices, SRB

PortalClientStub

PortalClientStub

PortalClientStub

JDBC,Local, orRemote

Connection

Three-Tiered ArchitectureThree-Tiered Architecture

Three-tiered architecture is accepted standard for Three-tiered architecture is accepted standard for accessing Grid and other servicesaccessing Grid and other services

JSR 168 OverviewJSR 168 Overview

Java Portlet StandardJava Portlet Standard

What Is a Portlet?What Is a Portlet? A portlet is a piece of Java code that manages the A portlet is a piece of Java code that manages the

content of one section of a web portal’s HTML.content of one section of a web portal’s HTML. It can do anything else that a Java web application It can do anything else that a Java web application

can do.can do.• You can connect a portlet to a database, invoke a web You can connect a portlet to a database, invoke a web

service, download an RSS feed, etc.service, download an RSS feed, etc. It lives in a It lives in a portlet containerportlet container, which creates, , which creates,

manages, and destroys all the portlets of the portal.manages, and destroys all the portlets of the portal. Portlet containers are part of portals.Portlet containers are part of portals.

• Portals must do other things like manage login, users, Portals must do other things like manage login, users, groups, layouts, etc.groups, layouts, etc.

JSR 168JSR 168 standardizes two main things: standardizes two main things:• How the portlet container manages portlet lifecyclesHow the portlet container manages portlet lifecycles• How the portlets are programmed.How the portlets are programmed.

What is JSR 168?What is JSR 168? From the portlet development point of view, From the portlet development point of view,

it is really very simple:it is really very simple:• You write a java class that extends You write a java class that extends

GenericPortletGenericPortlet..• You override/implement several methods You override/implement several methods

inherited from GenericPortlet.inherited from GenericPortlet.• You use some supporting classes/interfacesYou use some supporting classes/interfaces

Many are analogous to their Many are analogous to their servlet equivalentsservlet equivalents Some (portletsession) actually seem to be trivial Some (portletsession) actually seem to be trivial

wrappers around servlet equivalents in Pluto.wrappers around servlet equivalents in Pluto. A complete example is available from A complete example is available from

• http://www.servogrid.org/slide/iSERVO/NMI/http://www.servogrid.org/slide/iSERVO/NMI/OGCETutorialMaterialOGCETutorialMaterial

Some Open Source JSR 168 Some Open Source JSR 168 ContainersContainers

GridSphereGridSphere• http://http://www.gridsphere.orgwww.gridsphere.org

uPortaluPortal• http://http://www.uportal.orgwww.uportal.org

LifeRayLifeRay• http://http://sourceforge.net/projects/lportalsourceforge.net/projects/lportal

eXo platformeXo platform• http://http://www.exoplatform.comwww.exoplatform.com

StringBeansStringBeans• http://www.nabh.com/projects/sbportalhttp://www.nabh.com/projects/sbportal

Jetspeed2Jetspeed2• http://portals.apache.org/jetspeed-2/http://portals.apache.org/jetspeed-2/

Some GenericPortlet.java MethodsSome GenericPortlet.java MethodsMethodMethod DescriptionDescription

InitInit Called when the portlet is created. Called when the portlet is created. Override if you need to set initial params.Override if you need to set initial params.

doViewdoView Controls what happens immediately Controls what happens immediately before the portlet is displayed in view before the portlet is displayed in view mode. Normally you override this.mode. Normally you override this.

doHelp, doEditdoHelp, doEdit Other portlet display modesOther portlet display modes

processActionprocessAction Place for handling any <form> actions Place for handling any <form> actions before turning over to the display mode before turning over to the display mode method (like doView). You should override method (like doView). You should override this for web forms.this for web forms.

Some Supporting Classes/InterfacesSome Supporting Classes/InterfacesClassClass DescriptionDescription

PortletContextPortletContext Similar to servlet context; get context info and Similar to servlet context; get context info and the RequestDispatcher from here.the RequestDispatcher from here.

PortletSessionPortletSession Stores attribute information for a single portlet Stores attribute information for a single portlet application across multiple requests. application across multiple requests.

RenderRequest, RenderRequest, RenderResponseRenderResponse

The request and response objects available to The request and response objects available to the doView() method. Similar to the normal the doView() method. Similar to the normal servlet requestservlet request

ActionRequest,ActioActionRequest,ActionResponsenResponse

The request and response objects available to The request and response objects available to the processAction() method. Similar to the the processAction() method. Similar to the servlet request and response objects.servlet request and response objects.

PortletURLPortletURL Use this to create URLs that reference the portal.Use this to create URLs that reference the portal.

PortletRequestDispaPortletRequestDispatchertcher

Use this to include/forward to a JSP or servlet in Use this to include/forward to a JSP or servlet in the same portlet app.the same portlet app.

WindowStateWindowState See if you are in minimized, maximized, normal See if you are in minimized, maximized, normal state.state.

The Big PictureThe Big Picture As a portlet developer, the previous set of classes are all you As a portlet developer, the previous set of classes are all you

normally touch.normally touch. The portlet container is responsible for running your portlets.The portlet container is responsible for running your portlets.

• Init, invoke methods, destroy. Init, invoke methods, destroy. Portlets have a very limited way of interacting with the Portlets have a very limited way of interacting with the

container.container.• The API is basically one-way.The API is basically one-way.

In Action: Get started.public class JunkPortlet extends GenericPortlet {

public void init(){

//Do any initialization.

}

//Rest of the methods on following slides go here.

…

}

Override doView() protected void doView( RenderRequest req, RenderResponse

res) throws PortletException, IOException {//Include the desired JSP or HTML page.//We could also use out to write directly to the response.WindowState state=req.getWindowState();if(!state.equals(WindowState.MINIMIZED)) { res.setContentType("text/html"); PortletRequestDispatcher rd=

getPortletContext().getRequestDispatcher(“MyJSP.jsp”); rd.include(req,res);}

}

The JSP Page<portlet:defineObjects/><%PortletSession

portletSession=renderRequest.getPortletSession();portletSession.setAttribute("localattname","localattval");PortletURL url=renderResponse.createActionURL();String theActionString=url.toString();%>HTML Content is here. A form is below.<form method=post action="<%=theActionString%>"><input type=…></form>

Some Notes• Include the <%portlet:definedObjects/%> tag, which will

instantiate renderRequest, renderResponse, and portletConfig objects.– You can then just use them, as with request, response, and other

JSP implicit objects.• The renderRequest gives you access to the PortletSession,

if you want to store session variables.– One of the trouble points.

• The renderResponse gives you access to the PortletURL object.

• Use the PortletURL to generate a URL for the <form action>– So that it points to portlet container and gets handled by the

processAction() method, rather than going of into space.– Handle href URLs similarly.– This is one of the sticking points.

Lastly, Override processAction()• When you invoke the form on

the previous JSP, the portlet container will pass the action handling to the processAction method.

• The ActionRequest can be used to get any of the <input> parameters in a way similar to the usual HttpServletRequest.

• When the processAction method returns, the container then invokes the appropriate do method (usually doView).

• If you need to pass <form> parameters on to doView, add them to the ActionResponse.– This will give them to the

RenderRequest.– The example shows how to

add ALL parameters.

public void processAction (ActionRequest request, ActionResponse actionResponse) throws PortletException, java.io.IOException {//Process request parameters …//Add other params// to the renderRequest

actionResponse.setRenderParameters(request.getParameterMap());

}

A Comment on Portlet CodingA Comment on Portlet Coding JSR 168 seems to make some important and JSR 168 seems to make some important and

dubious assumptionsdubious assumptions• Developers will gladly ignore other development Developers will gladly ignore other development

methodologies/frameworks like methodologies/frameworks like Velocity, Struts, and Java Velocity, Struts, and Java Server Faces.Server Faces.

• Developers instead want to write a GenericPortlet extension Developers instead want to write a GenericPortlet extension for every single portlet they develop.for every single portlet they develop.

And write really complicated processAction() and doView() And write really complicated processAction() and doView() methods.methods.

• Developers will like the specific JSR 168 Developers will like the specific JSR 168 portlet-style Model-portlet-style Model-View-ControllerView-Controller that it forces on them. that it forces on them.

Fortunately, these other development environments Fortunately, these other development environments can be mapped to portlet actions. can be mapped to portlet actions. • In the OGCE project, we have developed support for In the OGCE project, we have developed support for

Velocity portlets.Velocity portlets.• We are transitioning to Java Server FacesWe are transitioning to Java Server Faces

A Grid Portlet ScenarioA Grid Portlet Scenario

Developing a Simple Grid Developing a Simple Grid Portlet ApplicationPortlet Application

A Quantum Chemistry Code A Quantum Chemistry Code Submission FormSubmission Form

You have been asked to develop a You have been asked to develop a submission form for the Democritos submission form for the Democritos group’s group’s Quantum EspressoQuantum Espresso (QE) package. (QE) package.

These forms should help users set up and These forms should help users set up and run QE applications on the run QE applications on the TeraGridTeraGrid and and other Grid installations.other Grid installations.• Mix of GT 2, GT 4, Condor, etc., for submissionMix of GT 2, GT 4, Condor, etc., for submission

You are told to initially support the You are told to initially support the Plane Plane Wave Self Consistent FieldWave Self Consistent Field (PWSCF) code. (PWSCF) code.

Other QE applications may follow.Other QE applications may follow.• These may be coupled with PWSCF into simple These may be coupled with PWSCF into simple

workflows, but this is a later problem.workflows, but this is a later problem.

Your Deployment ArchitectureYour Deployment Architecture

PortalServer@FSU

GT 4@TG

MSIPBS

GT 2@UMN

TeraGridLSF

Your portal server runs at FSU.

It acts as a common Gateway to different grid toolkit installations and resources

Some IssuesSome Issues

You decide the JSR 168 style portlets are You decide the JSR 168 style portlets are the way to go…the way to go…• But of course the PWSCF portlet doesn’t exist But of course the PWSCF portlet doesn’t exist

yet.yet. You will need to also support other You will need to also support other

Quantum Espresso codes.Quantum Espresso codes.• Would like to reuse as much code as possible.Would like to reuse as much code as possible.• But your PWSCF portlet isn’t reusable at that But your PWSCF portlet isn’t reusable at that

level.level. You also would like to simplify saving user You also would like to simplify saving user

input data and session archiving.input data and session archiving.

PWSCF Web Forms for PWSCF Web Forms for SubmissionSubmission

Your ChoicesYour Choices JSR 168JSR 168 will allow you to share your portlet code with will allow you to share your portlet code with

other collaborators.other collaborators. The The Java COG KitJava COG Kit will help hide the differences will help hide the differences

between Grid toolkits for common tasks.between Grid toolkits for common tasks. Vanilla JSFVanilla JSF will help simplify your portlet will help simplify your portlet

development in several ways.development in several ways.• JSF decouples your backing code from the Servlet APIJSF decouples your backing code from the Servlet API

You can write your backing code as pure Java Beans/Plain Old You can write your backing code as pure Java Beans/Plain Old Java Objects.Java Objects.

You don’t have to adopt, maintain HTTP parameter name You don’t have to adopt, maintain HTTP parameter name conventions.conventions.

• Your form input backing beans can be serialized/deserialized Your form input backing beans can be serialized/deserialized with Castor.with Castor.

Coupling JSF and COGCoupling JSF and COG will allow you to compose will allow you to compose your Grid actions using simple JSF taglibs.your Grid actions using simple JSF taglibs.• You can reuse your Grid taglibs in other Quantum Espresso You can reuse your Grid taglibs in other Quantum Espresso

portlets.portlets.• You can compose composite actions You can compose composite actions

The Java CoG KitThe Java CoG Kit

Gregor von LaszewskiGregor von LaszewskiArgonne National LaboratoryArgonne National Laboratory

University of ChicagoUniversity of Chicagogregor@mcs.anl.govgregor@mcs.anl.govhttp://www.cogkit.orghttp://www.cogkit.org

(as interpreted by MEP)(as interpreted by MEP)

CoG KitsCoG Kits

CoG Kits make Grid programming simple and CoG Kits make Grid programming simple and new technologies are easy to integratenew technologies are easy to integrate

We focus on a CoG Kit for JavaWe focus on a CoG Kit for Java• Python also available (K. Jackson, LBNL)Python also available (K. Jackson, LBNL)• Availability: Java CoG Kit since 1997Availability: Java CoG Kit since 1997

The CoG provides two important thingsThe CoG provides two important things• A higher level client programming environment A higher level client programming environment

than stubs.than stubs.• A shield against different versions of the Globus A shield against different versions of the Globus

toolkittoolkit Same high level API works with GT 2.4, GT 3.0.2, GT 3.2.0, Same high level API works with GT 2.4, GT 3.0.2, GT 3.2.0,

GT 3.2.1, GT 4.0.0GT 3.2.1, GT 4.0.0

CoG Abstraction Layer

CoG CoG CoG CoG CoG

CoG Data and Task Management Layer

CoG Gridfaces Layer

CoG CoG

CoG

GridID

E

GT2GT3OGSI

classic

GT4WS-RF

Condor Unicore

Applications

SSHOthersAvakiSETI

Nanomaterials

Bio-Informatics

DisasterManagement

Portals

CoG Abstraction Layer

CoG CoG CoG CoG CoG

CoG Data and Task Management Layer

CoG Gridfaces Layer

CoG CoG

CoG

GridID

E

DevelopmentSupport

CoG Abstraction Layers CoG Abstraction Layers

TaskTask

Handler

Service

TaskSpecification

SecurityContext

ServiceContact

The class diagram is thesame for all grid tasks (running jobs, modifying files, moving data).

Classes also abstract toolkit provider differences. You set these as parameters: GT2, GT4, etc.

Setting Up Task and SpecificationSetting Up Task and Specification

Task task=new TaskImpl(“mytask”,Task task=new TaskImpl(“mytask”,Task.JOB_SUBMISSION);Task.JOB_SUBMISSION);

task.setProvider(“GT2”);task.setProvider(“GT2”);JobSpecification spec=JobSpecification spec=

new JobSpecificationImpl();new JobSpecificationImpl();spec.setExecutable(“rm”);spec.setExecutable(“rm”);spec.setBatchJob(true);spec.setBatchJob(true);spec.setArguments(“-r”);spec.setArguments(“-r”);……task.setSpecification(spec);task.setSpecification(spec);

Setting Up the Service and Security Setting Up the Service and Security ContextContext

Service service=new Service service=new ServiceImpl(Service.JOB_SUBMISSION);ServiceImpl(Service.JOB_SUBMISSION);

service.setProvider(“GT2”);service.setProvider(“GT2”);

SecurityContext securityContext=SecurityContext securityContext=

CoreFactory.newSecurityContext(“GT2”);CoreFactory.newSecurityContext(“GT2”);

//Use cred object from ProxyManager//Use cred object from ProxyManager

securityContext.setCredentials(cred);securityContext.setCredentials(cred);

service.setSecurityContext(service.setSecurityContext(

(SecurityContext)securityContext);(SecurityContext)securityContext);

Set Up Service Contact and Set Up Service Contact and FinishFinish

ServiceContact serviceContact=ServiceContact serviceContact=

new ServiceContact(“myhost.myorg.org”);new ServiceContact(“myhost.myorg.org”);

service.setServiceContact(serviceContact);service.setServiceContact(serviceContact);

task.setService(task.setService(

Service.JOB_SUBMISSION_SERVICE,Service.JOB_SUBMISSION_SERVICE,

service);service);

TaskHandler handler=new TaskHandler handler=new GenericTaskHandler();GenericTaskHandler();

handler.submit(task);handler.submit(task);

Coupling CoG TasksCoupling CoG Tasks

The COG The COG abstractions also abstractions also simplify creating simplify creating coupled tasks.coupled tasks.

Tasks can be Tasks can be assembled into assembled into task graphs with task graphs with dependencies.dependencies.• ““Do Task B after Do Task B after

successful Task A”successful Task A” Graphs can be Graphs can be

nested.nested.

Java COG SummaryJava COG Summary The Java COG 4 interfaces provide high level The Java COG 4 interfaces provide high level

abstractions for building Grid clients.abstractions for building Grid clients.• Abstract out differences between Grid toolkits.Abstract out differences between Grid toolkits.• Provide task abstractions that form the basis for Provide task abstractions that form the basis for

constructing DAG-style, file-based workflow.constructing DAG-style, file-based workflow. The COG can be used to build a wide range of The COG can be used to build a wide range of

clientsclients• Desktops, grid shells, and of course portals.Desktops, grid shells, and of course portals.• Portlets are a well known way to build reusable Portlets are a well known way to build reusable

portal components.portal components.

Building Grid Portlets Building Grid Portlets with Java Server Faceswith Java Server Faces

Limitations of PortletsLimitations of Portlets Portlets provide a way to bundle and share a Portlets provide a way to bundle and share a

complete application.complete application.• RSS portlet, GridFTP portlet, SRB portlet, etc.RSS portlet, GridFTP portlet, SRB portlet, etc.• Portlets combine the user interface view and Portlets combine the user interface view and

action code.action code. But in science gateway development, we But in science gateway development, we

often need finer grained components.often need finer grained components.• ““When user clicks button, upload file, launch code, When user clicks button, upload file, launch code,

and move data someplace when done.”and move data someplace when done.”• Combines “GridFTP” and “Job Submit” portlets…Combines “GridFTP” and “Job Submit” portlets…• Or maybe OGSA-DAI or SRB or ….Or maybe OGSA-DAI or SRB or ….

We need a way for the view and action code We need a way for the view and action code to be developed from reusable parts.to be developed from reusable parts.

JSF and Science GatewaysJSF and Science Gateways JSF enables you to back your science JSF enables you to back your science

application input form portlets with Java Beans.application input form portlets with Java Beans.• These are independent of the servlet container, so These are independent of the servlet container, so

are easy to test and to reuse in other applications.are easy to test and to reuse in other applications. But also, Java Beans can be easily serialized But also, Java Beans can be easily serialized

with XML.with XML.• Castor, XML BeansCastor, XML Beans• Marshal and un-marshal user input for persistent Marshal and un-marshal user input for persistent

storage in XML storage servicesstorage in XML storage services OGSA-DAI, GPIR, WS-ContextOGSA-DAI, GPIR, WS-Context

• Potentially, can develop backing code as XML Potentially, can develop backing code as XML Schema and generate the code.Schema and generate the code.

JSF for Grid Enabled HTML JSF for Grid Enabled HTML WidgetsWidgets

Natural program: develop Java Bean Natural program: develop Java Bean wrappers around Java COG kit, OGSA-DAI wrappers around Java COG kit, OGSA-DAI client API, SRB Jargon, etc.client API, SRB Jargon, etc.• Allows simple integration with JSF.Allows simple integration with JSF.

Some issues existSome issues exist• JSF only manages individual bean instances.JSF only manages individual bean instances.• But grid portlets will need to manage an unknown But grid portlets will need to manage an unknown

number of bean instances.number of bean instances. You may launch and monitor many different jobs.You may launch and monitor many different jobs.

• We need a way of scripting composite actions We need a way of scripting composite actions created out of multiple reusable actions.created out of multiple reusable actions.

COG Bean WrappersCOG Bean Wrappers Recall the COG structureRecall the COG structure

• Executable tasks abstract basic grid Executable tasks abstract basic grid actions and hide toolkit version actions and hide toolkit version differences.differences.

• These tasks can be collected into file-These tasks can be collected into file-based DAG workflows.based DAG workflows.

First problem is simple: wrap tasks as First problem is simple: wrap tasks as beans to make them available to JSF.beans to make them available to JSF.• GenericGridBean defines the interfaceGenericGridBean defines the interface

Second problem is managing multiple Second problem is managing multiple individual tasks.individual tasks.

Managing Multiple Grid TasksManaging Multiple Grid Tasks We must create and manage multiple beans We must create and manage multiple beans

for each task.for each task.• That is, I submit the job four times in one session.That is, I submit the job four times in one session.• Similarly, we can create multiple task graph Similarly, we can create multiple task graph

clones. clones. We do this by cloning and storing each bean.We do this by cloning and storing each bean. Beans have listeners and maintain state.Beans have listeners and maintain state.

• Unsubmitted, submitted, active, suspended, Unsubmitted, submitted, active, suspended, resumed are “live”resumed are “live”

Stored in live repositoryStored in live repository

• Failed, canceled, completed, unknown are “dead” Failed, canceled, completed, unknown are “dead” Stored in archive (WS-Context or other)Stored in archive (WS-Context or other)

Alternative approach: use one bean that is a Alternative approach: use one bean that is a bean factory for GenericGridTask beans.bean factory for GenericGridTask beans.

<h:panelGrid columns="3" > <h:outputText value="Hostname (*) "/> <h:inputText value="#{task.hostname}"/> </h:panelGrid> <h:panelGrid columns="3" > <h:outputText value="Provider (*) "/> <h:inputText value="#{task.provider}"/></h:panelGrid>

Corresponding JSF snippets<o:taskGraph id="myGraph" method="#{taskgraph.test}" > <o:task id="task1" method="task.create" type="FileTransfer" /> <o:task id="task2" method="task.create" type="JobSubmit" /> <o:task id="task3" method="task.create" type="FileTransfer" /> <o:taskAdd name="task1" method="taskgraph.add" /> <o:taskAdd name="task2" depends="task1“

method="taskgraph.add" /> <o:taskAdd name="task3" depends="task2" method="taskgraph.add" /> </o:taskGraph>

<h:panelGrid columns="2"> <h:commandButton id="submit" value="Submit" action="#{taskgraph.submitAction}"/> <h:commandButton value="Clear" type="Reset"/> </h:panelGrid>

Task Monitoring with JSF Task Monitoring with JSF Data ModelData Model

<h:dataTable value="#{jobData.jobs}" var="job"> <h:column> <f:facet name="header"> <h:outputText style="font-weight: bold" value="Job ID" /> </f:facet> <h:outputText value="#{job.jobId}"/> </h:column> <h:column> <f:facet name="header"> <h:outputText style="font-weight: bold" value="Submit Date" /> </f:facet> <h:outputText value="#{job.submitDate}"/> </h:column> <h:column> <f:facet name="header"> <h:outputText style="font-weight: bold" value="Finish Date" /> </f:facet> <h:outputText value="#{job.finishDate}"/> </h:column> <h:column> <f:facet name="header"> <h:outputText style="font-weight: bold" value="Status" /> </f:facet> <h:outputText value="#{job.status}"/> </h:column> </h:dataTable>

Corresponding Java class.public class Job { private String jobId; private String status; private String submitDate; private String finishDate;}

Using AJAXUsing AJAX

Galip Aydin, Ahmet Sayar, and Galip Aydin, Ahmet Sayar, and Marlon PierceMarlon Pierce

Community Grids LabCommunity Grids LabIndiana UniversityIndiana University

What Is AJAX?What Is AJAX? AAsynchronous synchronous JJavaScript avaScript aand nd XXML is a combination of ML is a combination of

standard Web technologiesstandard Web technologies• JavaScript, CSS, DOM, XMLJavaScript, CSS, DOM, XML

When done properly, it provides apparently seamless When done properly, it provides apparently seamless interactivity in browser clients.interactivity in browser clients.• No browser reloadsNo browser reloads• Much smoother than standard request-wait-response for Much smoother than standard request-wait-response for

browser forms.browser forms. Several Google tools are a very well known Several Google tools are a very well known

examples.examples.• Google maps, Gmail, etc.Google maps, Gmail, etc.

The real key is the standardization of the The real key is the standardization of the XMLHttpRequest ObjectXMLHttpRequest Object• Originally developed for Internet ExplorerOriginally developed for Internet Explorer• Now supported by all major browsers.Now supported by all major browsers.

Seminal article from Adaptive PathSeminal article from Adaptive Path• http://www.adaptivepath.com/publications/essays/archives/0http://www.adaptivepath.com/publications/essays/archives/0

00385.php00385.php

AJAX ArchitectureAJAX Architecture

Taken from http://www.adaptivepath.com/publications/essays/archives/000385.php

The Main Idea: Asynchronous The Main Idea: Asynchronous JavaScript Calls to ServerJavaScript Calls to Server

AJAX’s key concept is the use of AJAX’s key concept is the use of XMLHttpRequest to buffer requests and XMLHttpRequest to buffer requests and responses within the browser.responses within the browser.• Use XMLHttpRequest to make a call to the server Use XMLHttpRequest to make a call to the server

and get back the response without displaying it.and get back the response without displaying it.• The response is stored locally as either plain text The response is stored locally as either plain text

(plain or HTML), or XML.(plain or HTML), or XML.• JavaScript + DOM can be used to walk the HTML JavaScript + DOM can be used to walk the HTML

or XML tree to handle most user interactions.or XML tree to handle most user interactions. The XMLHttpRequest object in turn can issue The XMLHttpRequest object in turn can issue

requests and process responses requests and process responses independently of the user’s interaction.independently of the user’s interaction.• Go and fetch additional maps, for example.Go and fetch additional maps, for example.

Asynchronous InvocationsAsynchronous Invocations

How it WorksHow it Works

Simple Example: GIS and Google Simple Example: GIS and Google MapsMaps

The Web Feature Service is a standard The Web Feature Service is a standard geographical information system service.geographical information system service.• It stores geographic features and metadata used It stores geographic features and metadata used

to construct maps.to construct maps.• Features are represented with the Geographic Features are represented with the Geographic

Markup LanguageMarkup Language• For example, the location and properties of For example, the location and properties of

earthquake faults and seismic events.earthquake faults and seismic events. The Feature Service is typically constructed The Feature Service is typically constructed

around traditional request-response.around traditional request-response. We would like to combine this with Google We would like to combine this with Google

Maps to make more interactive user Maps to make more interactive user interfaces.interfaces.

So let’s get started.So let’s get started.

Integrating Google Maps and GIS Integrating Google Maps and GIS ServicesServices

ClientMAP interface

Google MapServer

OGC WFSFeature Data Server

Simple Architecture

Supported Feature Data by the WFS

Layer specific parameters for filtering

Making the request Making the request Creating an XMLHttpRequest ObjectCreating an XMLHttpRequest Object

• For any browser, except IEFor any browser, except IE var requester = new XMLHttpRequest();var requester = new XMLHttpRequest();

• In IEIn IE var requester = new ActiveXObject("Microsoft.XMLHTTP");var requester = new ActiveXObject("Microsoft.XMLHTTP");

Transporting Data using an XMLHttpRequest Transporting Data using an XMLHttpRequest Object Object • To retrieve data from the server we use two methodsTo retrieve data from the server we use two methods: :

open() open() to initialize the connection, to initialize the connection, send()send() to activate the connection and make the to activate the connection and make the request. request. requester.open("GET", "getFaultNames.jsp?State=CA"); requester.open("GET", "getFaultNames.jsp?State=CA"); requester.send(null);requester.send(null);

This request is for all California fault information This request is for all California fault information in the Feature Service.in the Feature Service.• It will be encoded in GMLIt will be encoded in GML• It may take a bit of time to download….It may take a bit of time to download….

Checking the Connection StatusChecking the Connection Status To find out if the data retrieval is done we check To find out if the data retrieval is done we check

the status of the the status of the readyStatereadyState variable. Object’s variable. Object’s status may be any of the following:status may be any of the following:

0 – Uninitialised 0 – Uninitialised 1 – Loading 1 – Loading 2 – Loaded 2 – Loaded 3 – Interactive 3 – Interactive 4 – Completed 4 – Completed

• requester.onreadystatechangerequester.onreadystatechange monitors the monitors the readyStatereadyState variables status.variables status.if (requester.readyState == 4){ if (requester.readyState == 4){    if (requester.status == 200){ if (requester.status == 200){    success();    success();  }  } else{ else{    failure();    failure();

}} } }

Parsing the DataParsing the Data After a successful request After a successful request XMLHttpRequestXMLHttpRequest object may hold object may hold

data in one of the two properties: responseXML or data in one of the two properties: responseXML or responseText.responseText.

responseXMLresponseXML stores a DOM-structured XML data. stores a DOM-structured XML data. <Fault> <Fault>

<Name>San Andreas</Name> <Name>San Andreas</Name> </Fault> </Fault>

We use JavaScript XML parsing methods such as We use JavaScript XML parsing methods such as getElementsByTagName(), childNodes[], parentNode… getElementsByTagName(), childNodes[], parentNode… var faultNameNode = var faultNameNode =

requester.responseXML.getElementsByTagName(“Name")[0]; requester.responseXML.getElementsByTagName(“Name")[0]; var faultName = faultNameNode.childNodes[0].nodeValue;var faultName = faultNameNode.childNodes[0].nodeValue;

We can then use Google Map JavaScript functions to create We can then use Google Map JavaScript functions to create the browser display.the browser display.

responseTextresponseText stores the data as one complete string in stores the data as one complete string in case the content type of the data supplied by the server case the content type of the data supplied by the server was text/plain or text/html.was text/plain or text/html.

Ajax Calls From JSP PagesAjax Calls From JSP Pages

In the 1In the 1stst JSP page JSP page function checkForMessage() function checkForMessage()

{{

var url = "relay.jsp";var url = "relay.jsp";

initRequest(url);initRequest(url);

req.onreadystatechange = req.onreadystatechange = processReqChange;processReqChange;

req.open("GET", url, req.open("GET", url, true);true);

req.send(null);req.send(null);

}}

The request is The request is forwarded to relay.jspforwarded to relay.jsp

In the 2In the 2ndnd JSP page JSP page (relay.jsp)(relay.jsp)<%<%Bean.getNames(response);Bean.getNames(response);

%>%>

The response object The response object will contain the XML will contain the XML result object.result object.

Integrating Web Integrating Web Feature Service Feature Service

Archives and Archives and Google MapsGoogle Maps

Google maps can be integrated with Web Feature Service Archives to browse earthquake fault records.

Faults are typically stored by segment number, so map interfaces are convenient for both verifying continuity and setting up input files for computing problems.

Other Useful ExamplesOther Useful Examples AJAX is also useful for simulating server AJAX is also useful for simulating server

data pushing.data pushing.• Browser interface is updated periodically from Browser interface is updated periodically from

locally stored data. locally stored data. • XMLHttpRequest periodically requests updates XMLHttpRequest periodically requests updates

asyncrhonously.asyncrhonously. Replace annoying browser reload polling Replace annoying browser reload polling

and fragile, non-standard server push.and fragile, non-standard server push. The browser is always available for user The browser is always available for user

interactions while the XMLHttpRequest interactions while the XMLHttpRequest object is being updated.object is being updated.

Examples: Chat applications and GPS Examples: Chat applications and GPS streamsstreams

Real Time GPS Real Time GPS and Google Mapsand Google Maps

Subscribe to live GPS station. Position data from SOPAC is combined with Google map clients.

Select and zoom to GPS station location, click icons for more information.

ConclusionsConclusions Computing portals Computing portals scientific gateways. scientific gateways.

• Gateways include both user interface Gateways include both user interface components and supporting services.components and supporting services.

• Manage user interactions with Grid infrastructure.Manage user interactions with Grid infrastructure. We reviewed standards for building portals We reviewed standards for building portals

out of reusable components.out of reusable components.• JSR 168 portlet standardJSR 168 portlet standard

Several new techniques can be used to build Several new techniques can be used to build portlets.portlets.• Java Server Faces: reusable components for Java Server Faces: reusable components for

portlets.portlets.• AJAX: better interactivity for portletsAJAX: better interactivity for portlets

More InformationMore Information

mpierce@cs.indiana.edumpierce@cs.indiana.edu Open Grid Computing EnvironmentsOpen Grid Computing Environments

• http://www.collab-ogce.orghttp://www.collab-ogce.org Geographical Information System Geographical Information System

servicesservices• http://www.crisisgrid.orghttp://www.crisisgrid.org

QuakeSimQuakeSim• http://quakesim.jpl.nasa.govhttp://quakesim.jpl.nasa.gov

Integrating JSF and COG 4

Mehmet Nacar and Marlon Pierce

JSF for Grid Enabled HTML Widgets

• Natural program: develop Java Bean wrappers around Java COG kit, OGSA-DAI client API, SRB Jargon, etc.– Allows simple integration with JSF.

• Some issues exist– JSF only manages individual bean instances.– But grid portlets will need to manage an unknown

number of bean instances.• You may launch and monitor many different jobs.

– We need a way of scripting composite actions created out of multiple reusable actions.

COG Bean Wrappers• Recall the COG structure

– Executable tasks abstract basic grid actions and hide toolkit version differences.

– These tasks can be collected into file-based DAG workflows.

• First problem is simple: wrap tasks as beans to make them available to JSF.– GenericGridBean defines the interface

• Second problem is managing multiple individual tasks.

JSF Task Management Class Structure

Managing Multiple Grid Tasks• We must create and manage multiple beans for

each task.– That is, I submit the job four times in one session.– Similarly, we can create multiple task graph clones.

• We do this by cloning and storing each bean.• Beans have listeners and maintain state.

– Unsubmitted, submitted, active, suspended, resumed are “live”

• Stored in live repository

– Failed, canceled, completed, unknown are “dead” • Stored in archive (WS-Context or other)

• Alternative approach: use one bean that is a bean factory for GenericGridTask beans.

Managing Multiple Tasks

Task Manager

Task Bean

Task Bean 1

Task Bean 3

Task Bean 2

HashMap

Managed Beans

JSF Form

JSF

JSF

retrieve

register

Creating Task Graphs• COG Task Graphs correspond to composite

JSF Web Form actions.– Do X, Y, and then Z when user clicks the button.

• Each of these actions may be reused, but the entire action is new.

• We must do two things– Wrap the COG TaskGraphHandler with a bean

and bean manager.– Provide tag bindings for defining the custom

actions.

Constructing Task Graphs

Managed Beans

JobSubmit Bean

FileTransfer Bean

FileOperation Bean

HashMapTaskGraph Manager

TaskGraphBean

TaskGraph 1

TaskGraph 3

TaskGraph 2

JSF Request Form

JSF retrieve

JSF MonitoringForm

register

Expressing Task Graphs with Tags

<%@taglib uri="http://java.sun.com/jsf/core" prefix="f"%><%@taglib uri="http://java.sun.com/jsf/html" prefix="h"%><%@taglib uri="http://www.ogce.org/gsf/task" prefix="o"%>………………

<o:taskGraph id="myGraph" method="#{taskgraph.test}" > <o:task id="task1" method="task.create" type="FileTransfer" /> <o:task id="task2" method="task.create" type="JobSubmit" /> <o:task id="task3" method="task.create" type="FileTransfer" /> <o:taskAdd name="task1" method="taskgraph.add" /> <o:taskAdd name="task2" depends="task1" method="taskgraph.add" /> <o:taskAdd name="task3" depends="task2" method="taskgraph.add" /> </o:taskGraph>

<h:panelGrid columns="3" > <h:outputText value="Hostname (*) "/> <h:inputText value="#{task.hostname}"/> </h:panelGrid> <h:panelGrid columns="3" > <h:outputText value="Provider (*) "/> <h:inputText value="#{task.provider}"/></h:panelGrid>

Corresponding JSF snippets<o:taskGraph id="myGraph" method="#{taskgraph.test}" > <o:task id="task1" method="task.create" type="FileTransfer" /> <o:task id="task2" method="task.create" type="JobSubmit" /> <o:task id="task3" method="task.create" type="FileTransfer" /> <o:taskAdd name="task1" method="taskgraph.add" /> <o:taskAdd name="task2" depends="task1“

method="taskgraph.add" /> <o:taskAdd name="task3" depends="task2" method="taskgraph.add" /> </o:taskGraph>

<h:panelGrid columns="2"> <h:commandButton id="submit" value="Submit" action="#{taskgraph.submitAction}"/> <h:commandButton value="Clear" type="Reset"/> </h:panelGrid>

Task Monitoring with JSF Data Model

<h:dataTable value="#{jobData.jobs}" var="job"> <h:column> <f:facet name="header"> <h:outputText style="font-weight: bold" value="Job ID" /> </f:facet> <h:outputText value="#{job.jobId}"/> </h:column> <h:column> <f:facet name="header"> <h:outputText style="font-weight: bold" value="Submit Date" /> </f:facet> <h:outputText value="#{job.submitDate}"/> </h:column> <h:column> <f:facet name="header"> <h:outputText style="font-weight: bold" value="Finish Date" /> </f:facet> <h:outputText value="#{job.finishDate}"/> </h:column> <h:column> <f:facet name="header"> <h:outputText style="font-weight: bold" value="Status" /> </f:facet> <h:outputText value="#{job.status}"/> </h:column> </h:dataTable>

Corresponding Java class.public class Job { private String jobId; private String status; private String submitDate; private String finishDate;}

Extended Slides

The Java CoG Kit

Gregor von LaszewskiArgonne National Laboratory

University of Chicagogregor@mcs.anl.govhttp://www.cogkit.org

(as interpreted by MEP)

CoG Kits

• CoG Kits make Grid programming simple and new technologies are easy to integrate

• We focus on a CoG Kit for Java– Python also available (K. Jackson, LBNL)– Availability: Java CoG Kit since 1997

• The CoG provides two important things– A higher level client programming environment than

stubs.– A shield against different versions of the Globus toolkit

• Same high level API works with GT 2.4, GT 3.0.2, GT 3.2.0, GT 3.2.1, GT 4.0.0

CoG Abstraction Layer

CoG CoG CoG CoG CoG

CoG Data and Task Management Layer

CoG Gridfaces Layer

CoG CoG

CoG

GridID

E

GT2GT3OGSI

classic

GT4WS-RF

Condor Unicore

Applications

SSHOthersAvakiSETI

Nanomaterials

Bio-Informatics

DisasterManagement

Portals

CoG Abstraction Layer

CoG CoG CoG CoG CoG

CoG Data and Task Management Layer

CoG Gridfaces Layer

CoG CoG

CoG

GridID

E

DevelopmentSupport

CoG Abstraction Layers

TaskTask

Handler

Service

TaskSpecification

SecurityContext

ServiceContact

The class diagram is thesame for all grid tasks (running jobs, modifying files, moving data).

Classes also abstract toolkit provider differences. You set these as parameters: GT2, GT4, etc.

Java COG Summary• The Java COG 4 interfaces provide high level

abstractions for building Grid clients.– Abstract out differences between Grid toolkits.– Provide task abstractions that form the basis for

constructing DAG-style, file-based workflow.

• The COG can be used to build a wide range of clients– Desktops, grid shells, and of course portals.– Portlets are a well known way to build reusable portal

components.

Building Grid Portlets with Java Server Faces

Limitations of Portlets• Portlets provide a way to bundle and share a

complete application.– RSS portlet, GridFTP portlet, SRB portlet, etc.– Portlets combine the user interface view and action code.

• But in science gateway development, we often need finer grained components.– “When user clicks button, upload file, launch code, and

move data someplace when done.”– Combines “GridFTP” and “Job Submit” portlets…– Or maybe OGSA-DAI or SRB or ….

• We need a way for the view and action code must be developed from reusable parts.

PWSCF Web Forms for Submission

Java Server Faces Overview• JSF can solve the reusable portlet widget

problem.– JSF can also work in “standalone” mode outside

of portlets.– Potentially independent of Web applications.

• XUL and Swing widget bindings

• We will first examine JSF generally

• Conclude with integrating JSF and COG

Advantages of JSF

• JSF hides communication details that connect HTML forms with backing code.– You don’t have to worry about servlet specific request,

response, and session objects.– You don’t have to maintain fragile naming conventions for

<input> tags.• Developers only need to develop JavaBeans and

tag libraries.– Beans are independent of Web applications.– Can be easily written and tested outside of servlet

containers.– Compatible popular “Inversion of Control” based systems

like JSF and Spring

JSF and Science Gateways• JSF enables you back your science application input

form portlets with Java Beans.– Again, these are independent of the servlet container, so

are easy to test and to reuse in other applications.

• But also, Java Beans can be easily serialized with XML.– Castor, XML Beans– Marshal and un-marshal user input for persistent storage in

XML storage services• OGSA-DAI, GPIR, WS-Context

– Potentially, can develop backing code as XML Schema and generate the code.

A JSF Example<HTML> <HEAD> <title>Hello</title> </HEAD> <%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %> <%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %> <body bgcolor="white"> <f:view> <h:form id="entryForm" > <h2> Enter some text in the form below</h2> <h:inputText id="userSt"

value="#{multiEventBean.userString}"/> <h:commandButton id="submit"

action="success" value="Submit" > <f:actionListener type="multiEventTest.Listener1"/> <f:actionListener type="multiEventTest.Listener2"/> </h:commandButton> </h:form> </f:view> </body></HTML>

The JSF Page• Note everything with <f:> or <h:> namespace prefix is a JSF

tag. – Usually, <h:> tags mimic HTML widgets.– <f:> is for non-rendered stuff. – Everything else is good old HTML.

• There are three different Java classes here.– They are all in the package multiEventTest– multiEventBean.java is just a bean with typical get/set methods.– Listener1.java and Listener2.java implement the

javax.faces.event.ActionListener interface.• All 3 classes are called when you click the command button.• Also, take a look at <inputText>. This is roughly equivalent

to <input name=“” value=“”>.– But no name needed. JSF handles parameter names for you and

connects them to the beans you specify. – This greatly simplifies writing generic actions.

A Simple Example: HtmlDataGrid<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %><%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %><f:view> <h2> This shows an example of how to use HtmlDataTable to display some results. </h2> <h:dataTable value="#{ValueBean.itemList}" var="values" border="1"> <h:column> <f:facet name="header"> <h:outputText value="Column 1"/> </f:facet> <h:outputText value="#{values.value1}"/> </h:column> <h:column> <f:facet name="header"> <h:outputText value="Column 2"/> </f:facet> <h:outputText value="#{values.value2}"/> <h:outputText value="#{values.value2}"/> </h:column> </h:dataTable></f:view>

It Looks Like This

Some Explanation• The <h:dataTable> binds to a particular data set with

value=“ValueBean.itemList”.– ValueBean.itemList must be java.util.List, java.sql.ResultSet or

similar.– The values of these lists may be beans also.

• The var=“” just defines a useful internal value. – Here, each entry in the list is set equal to “values”.– In the example, the items in the list happen to be simple beans with

member variables “value1” and “value2” along with appropriate getter/setters.

• When you load the page, it just iterates through the entries in ValueBean.itemList and creates the table, as you instructed.

• Note again there are no loops in the actual page. Also, you don’t know anything about the data you are getting.

JSF Magic: Data Models• The M in MVC is the Data Model

– “Abstract” representation of a data structure • That is, not tied to the display of the data (“view”)

• JSF DataModel extension classes include– Arrays: wrap arrays of Java objects– Lists: wraps a java.util.List of Java objects– Results: for JSTL’s Result object, which itself wraps SQL ResultSets.– ResultSets: also for JDBC, wraps the ResultsSet object directly.– Scalar: Wraps an individual Java object.

• Typically, these should follow Bean patterns for naming member data and their associated getter/setters.

• You can write your own specialized Data Models.– XMLDataModel, for wrapping an XML data bean, comes to mind.– RSSDataModel is another that I found.

• These are associated with UIData classes in the JSF page for display. – HtmlDataTable is an example.

JSF Form Validators

• The user interface stuff (<f:> and <h:>) has lots of built-in validators – Verify that input entries are integers, doubles, etc.– Verify that input entries fall within the correct

range (1 to 10 in the guessNumber example).– Verify the string has the right length.

• You can extend to write your own specialized validators