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Building Science Gateways Marlon Pierce Community Grids Laboratory Indiana University What Is a Web Portal? Web container that aggregates content from multiple sources into a single display. “Start Pages” Typically consume RSS/Atom news feeds. More powerful versions these days support Flickr, calendars, games, etc. Gadgets, widgets Examples: iGoogle, Netvibes, My Yahoo! Grid Computing Overview Grid computing software is designed to integrate large supercomputing facilities. TeraGrid, Open Science Grid, EGEE, etc. This is done via network services Key Service Components Authentication and authorization framework (MyProxy) Remote process access and control (GRAM, Condor) Remote file, I/O access (GridFTP) Additional Services Information services, replica management, database federation, storage management, schedulers, etc. Example Grid Software Stacks: CTSS and VDT TeraGrid Supercomputing Resources (GPIR) Science Portals and Gateways Science Gateways adapt Web portal technology to build user interfaces to the Grid. Science portals resemble standard portals, but must also Support access to computing and storage resources. Allow users remote, Unix-like access to these resources. Provide access to science applications and data sets. And we must provide value added services as well as user interfaces. My 2002 “octopus” SOA diagram, from the archives. Browser Interface HTTP(S) Portlets + Client Stubs SOAP/HTTP WSDL DB Service WSDL WSDL WSDL WSDL WSDL WSDL WSDL Job Sub/Mon And File Services WSDL Visualization Service JDBC DB Operating and Queuing Systems DB Host 1 Host 2 Host 3 Terminology Portlet: this is a standard Java component that generates HTML and can also act as a client to a remote service. Lives in a portal container. I will also use this term generically. Web Service: a remotely invokeable function on the Internet. SOAP: the XML message envelop for carrying commands over HTTP. WSDL: describes the service’s API in XML. REST: A variation of this approach. Lots more info: http://grids.ucs.indiana.edu/ptliupages/presentations/I590 WebService.ppt But Why? Three-tiered Service Oriented Architecture is the network equivalent of the the famous Model-ViewController design pattern. View: the user interface components. Controller: Web service middleware Model: the backend resources. Independence of tiers gives flexibility Services can be reused with alternative user interfaces Workflow composers like Taverna User interfaces can work with different service implementations. Drawback: reliability and robustness are issues. Two Approaches to the Middle Tier Fat Client Thin Client Portal Client Portal Client Grid Client Grid Protocol (SOAP) HTTP + SOAP Web Service Grid Client Grid Protocol (SOAP) Grid Service Backend Resource Grid Service Backend Resource Disloc output converted to KML and plotted. GeoFEST Finite Element Modeling portlet and plotting tools What’s In the Screenshots? GeoFEST and Disloc Portlets Live on gf7.ucs.indiana.edu Manage the user’s display: Web forms, links to output, graphics. Save user session state persistently. QuakeTables Fault DB Web Service Lives on gf2.ucs.indiana.edu Contains geometric fault models. GeoFEST and Disloc Execution Web Services Lives on gf19.ucs.indiana.edu Generates input files from fault models. Runs and manages codes. Best Practice for Scientific Web Services There are many tools to choose from. .NET, Apache Axis, Sun WS, Ruby on Rails, etc. Make them self-contained. If possible, generate input files within the service. Or have an input file generating service. Remember that they may be used by other people with other client tools. Communicate data files with URLs. Be very careful about exposing the state of the service. Don’t assume persistent connections. Components for Portals Open Grid Computing Environments Examples. See http://www.collabogce.org/ Components for Science Portals OGCE is founded on the principal that portals should be built out of reusable parts. Key standard in our first phase: the JSR 168 portlet specification. Portlets can run in multiple containers uPortal, Sakai, GridSphere, LifeRay, etc. Allows us to build Grid specific components and deploy along side other goodies: Sakai collaboration tools, contributed portlets, etc. Future: Open Social compliant Google Gadgets OGCE GPIR portlet can interoperate with TeraGrid and your own GPIR services. Manage TeraGrid MyProxy credentials with the OGCE ProxyManager portlets. OGCE file management client portlets interact with TeraGrid GridFTP servers. General purpose batch and interactive job submission to GRAM, WS-GRAM is supported. Dashboard Portlet The dashboard portlet allows users to track jobs on the selected resource. The user can view either his own set of jobs or get information on all submitted jobs. 20 Queue forecasting portlets work with the NWS QBETS to predict wait times and deadlines. PURSe portlets manage user requests for portal accounts and Grid credentials. Condor and Condor-G OGCE IFrame Portlet can be used to integrate external sites. Client Libraries for Grid Computing Two Major Grid Client Efforts The Java COG Kit Supports several versions of Globus and SSH. Condor-G Has a Web Service interface (BirdBath) and Java client libraries. Supports Globus (v2 and v4) and several other Grid middleware systems. You can build either portlets or Web services with either of these. OGCE portlets use primarily COG We prefer Condor-G based Web services for long running jobs. CoG Abstraction Layers Nano materials BioDisaster Informatics Management Applications Portals Development Support CoGGridfaces GridfacesLayer Layer CoG CoG CoG GridIDE GridIDE CoGData Dataand andTask TaskManagement ManagementLayer Layer CoG CoGAbstraction AbstractionLayer Layer CoG CoG CoG CoG CoG CoG CoG GT2 GT3 (X) GT4 WS-RF CoG CoG CoG CoG Condor Unicore CoG CoG CoG CoG SSH Others Task Handler The class diagram is the same for all grid tasks (running jobs, modifying files, moving data). Task Task Specification Service Security Context Classes also abstract toolkit provider differences. You set these as parameters: GT2, GT4, etc. Service Contact 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. Problems with Grid Client Development Grid portlets typically wrap each single Grid capability in a separate portlet Problem is that Grid portlets need to combine these operations Portlets are entire web applications, so we need a component model for portlets: reusable portlet parts Even with the COG Abstraction Layer, we must still do a lot of coding to build new applications. To address these problems we have adopted Java Server Faces Provides several nice Model-View-Controller features JSF provides an extensible framework (tag libraries) for making reusable components. Apache JSF portlet bridge allows you to convert standalone JSF applications (development phase) into portlets (deployment phase). GTLAB Example <html> <body> <f:form> <o:submit id=”test” action=”next_page” /> <o:myproxy id=”pr” hostname=”gf1.ucs.indiana.edu” port=”7512” lifetime=”2” username=“mnacar” password=”***” /> <o:jobsubmit id=”task” hostname=”cobalt.ncsa.teragrid.org” provider=”GT4” executable=”/bin/ls” stdout=”tmp/result stderr=”tmp/error” /> </o:submit> </f:form> </body> </html> 32 Grid Tags Associated Grid Beans Features <submit/> ComponentBuilderBean Creating components, job handlers, submitting jobs <handler/> MonitorBean Handling monitoring page actions <multitask/> MultitaskBean Constructing simple workflow <dependency/> MultitaskBean Defining dependencies among sub jobs <myproxy/> MyproxyBean Retrieving myproxy credential <fileoperation/> FileOprationBean Providing Gridftp operations <jobsubmission/> JobSubmitBean Providing GRAM job submissions <filetransfer/> FileTransferBean Providing Gridftp file transfer ResourceBean Describes common properties among all tags and beans. Passing values given by standard visual JSF components. Managing Scientific Workflows Scientific Workflows Portal interfaces encode scientific use cases. If you have a rich set of services, it is a lot of work to make portlets for all possible use cases. And power users will have always want something more. Example: our CICC project has dozens of chemical informatics Web services. http://www.chembiogrid.org.wiki Workflow composers can simplify this. Allow users to encode and execute their own use cases. Web Services and Workflows Perform a similarity search on the NIH DTP Human Tumor data. Filter the results based on Pharmacokinetic properties (FILTER) Convert to 3D (OMEGA) Docking into a predefined protein (FRED) Visualize (JMOL). Taverna workflow connects remote services. OGCE’s XBaya Workflow Composer Future of Science Gateways Updating the Octopus Browser Interface HTTP(S) Social Gadgets+AJAX RSS,JSON/HTTP REST DB Service REST REST REST REST REST WSDL REST Job Sub/Mon And File Services REST Visualization Service JDBC DB Operating and Queuing Systems DB Host 1 Host 2 Host 3 Enterprise Approach Web 2.0 Approach JSR 168 Portlets Gadgets, Widgets Server-side integration and processing AJAX, client-side integration and processing, JavaScript SOAP RSS, Atom, JSON WSDL REST (GET, PUT, DELETE, POST) Portlet Containers Open Social Containers (Orkut, LinkedIn, Shindig); Facebook; StartPages User Centric Gateways Social Networking Portals Workflow managers (Taverna, Kepler, etc) Mash-ups Grid computing: Globus, condor, etc Cloud computing: Amazon WS Suite, Xen Virtualization Semantic Web: RDF, OWL, ontologies Microformats, folksonomies Microformats, KML, and GeoRSS feeds used to deliver SAR data to multiple clients. More Information Contact me: [email protected] See what I’m up to: http://communitygrids.blogspot.com/ OGCE software: http://collab-ogce.org/ QuakeSim: http://www.quakesim.org/ CICC: http://www.chembiogrid.org/wiki/ Lots of people worked on all of these.