A Portal Architecture Review

1. A Portal Architecture Review

2. Talk Overview • Portal architectures • JSR 168 review • A motivating example • Building grid clients with the Java COG. • Combining the Java COG with Java Server Faces.

3. A Famous Web Portal

4. A Famous Portal, After Login

5. What to Notice • After logging in, my colors, layouts, and content all changed. • I get my stock list, my Bloomington weather, my news stories, etc. • I got rid of “Garfield” • As we will see later, each of these content fragments (encircled) is managed by a thing called a portlet… • … I don’t guarantee that this is true for Yahoo’s web site but it is true for a large class of enterprise Java portal systems. • Portlets are the key to portal software reuse.

6. Let 10,000 Flowers Bloom • Many portal projects have been launched since late ’90s. • HotPage from SDSC, NCSA efforts, DOD, DOE Portals, NASA IPG • 2002 Special Issue of Concurrency and Computation: Practice and Experience. • The field continues to be active • Global Grid Forum 14 Science Gateway workshop in June 2005. • About 15 gateways will be described in upcoming issue of Concurrency. • GCE2005 workshop at Supercomputing 05. • http://www.ggf.org/ggf_events_lodging_ggf15.htm • How do we share and reuse all of this work?

7. Three-tiered architecture is accepted standard for accessing Grid and other services Three-Tiered Architecture Grid and Web Protocols JDBC, Local, or Remote Connection Portal Client Stub Database Service Database Portal User Interface Portal Client Stub Grid Resource Broker Service HPC or Compute Cluster Portal Client Stub Information and Data Services Grid Information Services, SRB

8. JSR 168 Overview Java Portlet Stadard

9. What Is a Portlet? • A portlet is a piece of Java code that manages the content of one section of a web portal’s HTML. • It can do anything else that a Java web application can do. • You can connect a portlet to a database, invoke a web service, download an RSS feed, etc. • It lives in a portlet container, which creates, manages, and destroys all the portlets of the portal. • Portlet containers are part of portals. • Portals must do other things like manage login, users, groups, layouts, etc. • JSR 168 standardizes two main things: • How the portlet container manages portlet lifecycles • How the portlets are programmed.

10. What is JSR 168? • From the portlet development point of view, it is really very simple: • You write a java class that extends GenericPortlet. • You override/implement several methods inherited from GenericPortlet. • You use some supporting classes/interfaces • Many are analogous to their servlet equivalents • Some (portletsession) actually seem to be trivial wrappers around servlet equivalents in Pluto. • I have a complete example in the extended slides. • See also tutorial slides.

11. Some Open Source JSR 168 Containers • GridSphere • http://www.gridsphere.org • uPortal • http://www.uportal.org • LifeRay • http://sourceforge.net/projects/lportal • eXo platform • http://www.exoplatform.com • StringBeans • http://www.nabh.com/projects/sbportal • Jetspeed2 • http://portals.apache.org/jetspeed-2/

12. Some GenericPortlet.java Methods

13. Some Supporting Classes/Interfaces

14. The Big Picture • As a portlet developer, the previous set of classes are all you normally touch. • The portlet container (Pluto) is responsible for running your portlets. • Init, invoke methods, destroy. • Portlets have a very limited way of interacting with the container. • The API is basically one-way.

15. A Comment on Portlet Coding • JSR 168 seems to make some important and dubious assumptions • Developers will gladly ignore other development methodologies/frameworks like Velocity, Struts, and Java Server Faces. • Developers instead want to write a GenericPortlet extension for every single portlet they develop. • And write really complicated processAction() and doView() methods. • Developers will like the specific JSR 168 portlet-style Model-View-Controller that it forces on them. • Fortunately, these other development environments can be mapped to portlet actions. • In the OGCE project, we have developed support for Velocity portlets. • We are transitioning to Java Server Faces

16. A Grid Portlet Scenario Developing a Simple Grid Portlet Application

17. A Quantum Chemistry Code Submission Form • You have been asked to develop a submission form for the Democritos group’s Quantum Espresso (QE) package. • These forms should help users set up and run QE applications on the TeraGrid and other Grid installations. • Mix of GT 2, GT 4, Condor, etc., for submission • You are told to initially support the Plane Wave Self Consistent Field (PWSCF) code. • Other QE applications may follow. • These may be coupled with PWSCF into simple workflows, but this is a later problem.

18. Your Deployment Architecture It acts as a common Gateway to different grid toolkit installations and resources Your portal server runs at FSU. GT 4 @TG TeraGrid LSF Portal Server @FSU GT 2 @UMN MSI PBS

19. Some Issues • You decide the JSR 168 style portlets are the way to go… • But of course the PWSCF portlet doesn’t exist yet. • You will need to also support other Quantum Espresso codes. • Would like to reuse as much code as possible. • But your PWSCF portlet isn’t reusable at that level. • You also would like to simplify saving user input data and session archiving.

20. PWSCF Web Forms for Submission

21. Your Choices • JSR 168 will allow you to share your portlet code with other collaborators. • The Java COG Kit will help hide the differences between Grid toolkits for common tasks. • Vanilla JSF will help simplify your portlet development in several ways. • JSF decouples your backing code from the Servlet API • You can write your backing code as pure Java Beans/Plain Old Java Objects. • You don’t have to adopt, maintain HTTP parameter name conventions. • Your form input backing beans can be serialized/deserialized with Castor. • Coupling JSF and COG will allow you to compose your Grid actions using simple JSF taglibs. • You can reuse your Grid taglibs in other Quantum Espresso portlets. • You can compose composite actions

22. The Java CoG Kit Gregor von Laszewski Argonne National Laboratory University of Chicago gregor@mcs.anl.gov http://www.cogkit.org (as interpreted by MEP)

23. 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

24. CoG Gridfaces Layer CoG Gridfaces Layer CoG Data and Task Management Layer CoG Data and Task Management Layer CoG GridIDE CoG GridIDE CoG Abstraction Layer CoG Abstraction Layer CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG Abstraction Layers Development Support Nano materials Bio- Informatics Disaster Management Portals Applications GT2 GT3 OGSI classic GT4 WS-RF Condor Unicore SSH Others Avaki SETI

25. Task Handler Task Task Specification The class diagram is the same for all grid tasks (running jobs, modifying files, moving data). Service Security Context Service Contact Classes also abstract toolkit provider differences. You set these as parameters: GT2, GT4, etc.

26. 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.

27. Building Grid Portlets with Java Server Faces

28. 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.

29. 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.

30. 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.

31. 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.

32. 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.

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

34. 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; }

35. Extended Slides

36. The Java CoG Kit Gregor von Laszewski Argonne National Laboratory University of Chicago gregor@mcs.anl.gov http://www.cogkit.org (as interpreted by MEP)

37. 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

38. CoG Gridfaces Layer CoG Gridfaces Layer CoG Data and Task Management Layer CoG Data and Task Management Layer CoG GridIDE CoG GridIDE CoG Abstraction Layer CoG Abstraction Layer CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG CoG Abstraction Layers Development Support Nano materials Bio- Informatics Disaster Management Portals Applications GT2 GT3 OGSI classic GT4 WS-RF Condor Unicore SSH Others Avaki SETI

40. Task Handler Task Task Specification The class diagram is the same for all grid tasks (running jobs, modifying files, moving data). Service Security Context Service Contact Classes also abstract toolkit provider differences. You set these as parameters: GT2, GT4, etc.

41. Setting Up Task and Specification Task task=new TaskImpl(“mytask”, Task.JOB_SUBMISSION); task.setProvider(“GT2”); JobSpecification spec= new JobSpecificationImpl(); spec.setExecutable(“rm”); spec.setBatchJob(true); spec.setArguments(“-r”); … task.setSpecification(spec);

42. Setting Up the Service and Security Context Service service=new ServiceImpl(Service.JOB_SUBMISSION); service.setProvider(“GT2”); SecurityContext securityContext= CoreFactory.newSecurityContext(“GT2”); //Use cred object from ProxyManager securityContext.setCredentials(cred); service.setSecurityContext( (SecurityContext)securityContext);

43. Set Up Service Contact and Finish ServiceContact serviceContact= new ServiceContact(“myhost.myorg.org”); service.setServiceContact(serviceContact); task.setService( Service.JOB_SUBMISSION_SERVICE, service); TaskHandler handler=new GenericTaskHandler(); handler.submit(task);

44. Coupling CoG Tasks • The COG abstractions also simplify creating coupled tasks. • Tasks can be assembled into task graphs with dependencies. • “Do Task B after successful Task A” • Graphs can be nested.

45. 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.

46. Building Grid Portlets with Java Server Faces

47. 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.

48. PWSCF Web Forms for Submission

49. 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

50. 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