September 14th, 2005 NEC 2005 Symposium The Information System of CMS Concepts, Technology and Architecture Zhechka Toteva Sofia University/CERN Dirk Samyn, Nick J. Sinanis CERN

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Introduction n Web content serving for the CMS collaboration u Agendas, Documentation, Dynamic Mailing Lists, People & Institutes u Sub-detector and Project Pages u Data samples, Software Distribution and Event Catalogues u Provide an integrated environment for all Collaboration generated knowledge n Some numbers u > 2’000 people, spread around the world l Availability around the clock! u > 90 GBytes/day of file transfers u > 18 kHits/hour n Current system dates from the first days of WWW u Mostly static content u Few dynamic content, often leading to unmanaged pages u “One size fits it all”

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium iCMS – What is it? n A modern web information system to replace the legacy CMSDOC n User perspective u handles the processing of different classes of CMS-specific information l Agendas, Announcements, Documentation, Mailing lists, Meetings, News, Notes, People & Institutes, Requests u Built on experience from the last 12 years running CMSDOC l Federated content management u Offers personalization l Functions/Roles in the experiment l Interests and working fields n System Perspective u Industrial standard technologies and techniques l Java, EJB, Web services u Scalable during the lifetime of the experiment l Multi-Tier architecture u High-performance l Content Separation

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Web Architectures n Classic architecture is a monolithic server u Simple l but scales poorly u Content access l Bottlenecks l Synchronization n Architecture evolution is to be expected at the server side tiers Data TierPresentation Tier Web Server HTML Simple Dynamic Content

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Building N-Tier Architectures Presentation Tier Apache JSP HTML Data Tier RDBMS File System Business Tier Tomcat Java Beans (EJB), RDF/RSS Work Flow Engine Data Access Tier Tomcat Axis Web Services Hibernate

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium iCMS 4-Tier Architecture

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Presentation Tier notesTypeslList.jsp Visualization of Web Components

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Presentation Tier notesTypeslList.jsp Visualization of Web Components Communicating with Business Tier

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Presentation Tier notesTypeslList.jsp Visualization of Web Components Communicating with Business Tier Procedural Logic

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Presentation Tier n Advantages of JSP Web Components u High Level of Tags Reuse l Adding New Pages u Modularity l Trivial Functionality Grouping l Development based on page components rather than HTML tags u Coherence l It’s enough to modify a tag at a single place in order to propagate everywhere u Portability l Standardized versions notesTypeslList.jsp Visualization of Web Components Communicating with Business Tier Procedural Logic

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Business Tier - Architecture n Processes the requests from the presentation tier n Implements the business logic of information processing u Workflow engine for documents submission/refereeing management n Stubs call the axis web services of the data access tier n Processes the RDF/RSS responses from the data access tier n Creates the java beans for the presentation tier

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Business Tier - RDF/RSS n Resource Description Framework (RDF) u W3D standard W3D standard u Describes documents using constraint definitions u processed by jenaRDF API processed by jenaRDF API n Really Simple Syndication (RSS) u Standard RSS 2.0 Standard RSS 2.0 u Syndicates the updates of frequently changing information (e.g., CMS news) n Advantages offered by RDF/RSS u Unified interface l Modular l Scalable u Syntax based on XML l Neutral presentation to the client l Universal language understood by other tools (e.g., news aggregator)

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Business Tier - BPEL4WS n Business Process Execution Language for Web Services (BPEL4WS) u Orchestration of web services l establishes the communication protocols l defines the business rules of the web services interactions n Applications of BPEL4WS u Describe the life cycle of CMS publications l A set of business rules of the interaction between the submitter, subeditors and editors (referees) n Twister workflow engine u Implements the business processes u Keeps track of the states of a process instance (publication) u the communication messages exchanged between parties participating in the publication processing u Provides client libraries to integrate with the business tier u BPEL4WS specification compliance l Extendibility, portability

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Data Access Tier - Web Services n Web service definition u Efficient serving of data query results and data manipulation requests l Standalone service l Data caching n Features u Unification of the communication interface l jdbc l rdf/rss u Modularity u Portability l web services standard n AXIS from Apache Foundation

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Data Access Tier - ORM n Object-relational Mapping (ORM) u Provides a seamless framework for object/relational persistence and query n Hibernate ORM Hibernate u DB data treated as objects l An object property contains list of related objects è Speeds-up processing of parent-child relationships u Extendibility l Supports SQL and JDBC standards l Extends the SQL query features with objects-based search criteria l UML support for advanced object- relational modeling u Performance l Frequently used objects caching

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Data Tier - RDBMS & FS Storage n MySQL RDBMS u Persistent storage of data u Ensures data consistency l domain constraints l referential integrity constraints l transactions u Provides multi-session data processing l Transaction isolation levels n File System (FS) storage u File level storage u Meta-data related to files are stored in a database

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium iCMS Site Presentation

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Summary n iCMS is the new generation information system of CMS n N-tier architectures have been studied u A 4-tier architecture has been chosen for iCMS n Advanced industrial standard technologies have been employed in order to provide for u Scalability u Portability u Extendibility n Status u First user experiences already collected u Goes into production in the coming weeks n Plans u CMS shifts management l prototype for Cosmic Challenge in 2006 u WIKI u Community forums

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Spare Slides

Zhechka Toteva CERN - CMS Computing September 14th, 2005 NEC 2005 Symposium Advantages n Coherent presentation to the end user – jsp web components n Standard web technologies employed u Web Services – provides the communication with relational databases’ persistent storage u Resource Description Framework (RDF) / Really Simple Syndication (RSS) – XML-based formats to describe the result information u Business Process Execution Language for Web Services (WPEL4WS) - describes the interaction between different web services n Unified interfaces for communication between different tiers: u JSP web components, Java beans, RDF, Axis remote calls, JDBC n Physically distributed on different servers