GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 LC Portal via GridSphere Mark Baker and Hong Ong Distributed Systems Group University of Portsmouth

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 Contents Overview of the Liquid Crystal (LC) application. Introduction to the LC Portal: –The early Perl based generation, –The next JSR 168 based generation. Comments on our experiences.

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 Liquid Crystal Application Modeling liquid crystalline materials. Determine minimum energy configuration of liquid crystals in a slab. Landau-de Gennes formulation in terms of tensor order parameter Q, and temperature T. Free energy is represented as: F(Q, T) = F vol (Q, T) + F surf (Q) =    f vol (Q, T) dV +    f surf (Q) dS, where  =  (x 1, x 2, x 3  x 1  a, 0  x 2  b, 0  x 3  c }.

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 Solving Free Energy Equation Solve the Euler-Lagrange equations. Consider 100 points per edge: –Give a linear system with 5x10 6 unknowns. –Use MINRES, Krylov subspace method. Written in C/Fortran. In-house MPI “BLAS” code. Visualization.

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 LC Portal: Architecture The architecture is based on the “three-tier” model. Presentation Web Logic Backend

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 LC Portal: Internal Architecture Direct socket connection to Grid Service

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 LC Portal: Workflow LC Web Portal Visualization Submission and Control LC Render Cluster MPI version of POVRay Job Submit and Control LC Compute Cluster MPI version of LC Code GSI-FTP 1 2 3

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 LC Portal: The 2002 Version

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 LC Portal: Interface Allow users to configure the liquid crystals representation. Allow users to modify the simulation parameters Allow user to change the viewing aspects Control buttons for submitting jobs.

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 Web Portal/Portlet Technologies Many Web portals implementations: –Create compatibility problems for Application Providers, Portal Consumers, and Portal Server. Web application development is a tedious task: –Lack of reusable components, –Developers constantly have to “re-invent” the wheel. Portal/Portlet standards include: –JSR-168: Similar to Servlet API for providing reusable web applications. –JSR-127: Specifies an event-based user interface for web presentation development. –Web Services for Remote Portlets (WSRP): Specifies how web services can be consumed by standards compliant portals.

Some Portal/Portlet Implementations Current vendors: –IBM WebSphere, –Oracle Portal, –Sun Application Server. Open source projects: –Jakarta Pluto (Jetspeed), Jetspeed 2, and wsrp4j, – Exo, Liferay, and Cocoon 2. Academic projects: –GridSphere, Sakai, and uPortal.

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 LC Portal: The 2004 version

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 LC Portal: Interface Resources Browser MyProxy Portlet LC Portlet

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 Comments on Some Experiences Recall, we wanted: –Client-> HTTP server -> Tomcat (either local or remote), –Clients should see only /, –Clients should access remote resource via Grid Portlets. At AHM, Hong talked to people who are using GS: –Found out none has investigated this route, –Changing the context.xml is not enough because GS assumes webapps are deploy to : /, Modified GS source code: –Fully integrated with Apache2 and Tomcat4 using mod_jk module. So, does it work?

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 The Good! Web Portal - one ring to rule them all. –A single interface to control distributed resources, –Workflow that cross multiple machines or organizations. Hiding complexity of the Web/Grid: –Manage complexity on one machine instead of many, –Uniform user environment. Delegating tasks: –Users hate to install/configure anything! –Web/Grid client software management remains challenging, –Developers handle the nitty gritty deployment details.

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 The Bad!

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 The Ugly!

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 Comments on Some Experiences Grid portlets from GS do not work (for us): –In the end, we used Grid portlets from OGCE, which include GridPort portlet. Configuration requires a lot of effort. Legacy application might not be able to represent as portlets. –So, do we have to start from scratch? Portlet development issues: –What is the trade off between a portlet orchestrating a lot of web services as compared to simply using WSRP? –Is it a good idea to write code in WSRP, JSR-168, JSR-127, or combination? –In the real world, a portal will be built from components from many sources, so are we back to square one again?

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 Comments on Some Experiences Firewall Issues: –Ports need to be opened for some services to communicate with each other, –Ports management remains challenging. Integration Issues: –If the WSRP to JSR-168 API works out well, each portal should both be a WSRP producer and consumer, –This implies significant opportunity for creating federated portals, –However, there is much work to do in this area to fully realize this potential at the moment.

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 Concluding Remarks Portlet standards provide a uniform way to develop a user Web portal. More portlets (Grid/Web) need to be made available. Applications presented as WS/Portlet has many benefits. Installation and deployment still remain challenging. Integration of portals/portlets still remain problematic. Most portlet frameworks are still research projects and may not be ready for prime time.

GridSphere/Portlet Workshop, March 3 rd – 4 th, 2005 Questions?