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gLite, the next generation middleware for Grid computing. Oxana Smirnova (Lund/CERN) Nordic Grid Neighborhood Meeting Link öping , October 20, 2004 Uses material from E.Laure and F.Hemmer. gLite. What is gLite : “the next generation middleware for grid computing”
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gLite, the next generation middleware for Grid computing Oxana Smirnova (Lund/CERN) Nordic Grid Neighborhood Meeting Linköping, October 20, 2004 Uses material from E.Laure and F.Hemmer
gLite • What is gLite: • “the next generation middleware for grid computing” • “collaborative efforts of more than 80 people in 10 different academic and industrial research centers” • “Part of the EGEE project (http://www.eu-egee.org)” • “bleeding-edge, best-of-breed framework for building grid applications tapping into the power of distributed computing and storage resources across the Internet” EGEE Activity Areas (quoted from http://www.glite.org) Nordic contributors: HIP, PDC, UiB 2
Architecture guiding principles • Lightweight services • Easily and quickly deployable • Use existing services where possible as basis for re-engineering • “Lightweight” does not mean less services or non- intrusiveness – it means modularity • Interoperability • Allow for multiple implementations • Performance/Scalability & Resilience/Fault Tolerance • Large-scale deployment and continuous usage • Portability • Being built on Scientific Linux and Windows • Co-existence with deployed infrastructure • Reduce requirements on participating sites • Flexible service deployment • Multiple services running on the same physical machine (if possible) • Co-existence with LCG-2 and OSG (US) are essential for the EGEE Grid service • Service oriented approach 60+ external dependencies … 3
Service-oriented approach • By adopting the Open Grid Services Architecture, with components that are: • Loosely coupled (messages) • Accessible across network; modular and self-contained; clean modes of failure • Can change implementation without changing interfaces • Can be developed in anticipation of new use cases • Follow WSRF standardization • No mature WSRF implementations exist to-date so start with plain WS • WSRF compliance is not an immediate goal, but the WSRF evolution is followed • WS-I compliance is important 4
LCG-1 LCG-2 gLite-1 gLite-2 Globus 2 based Web services based gLite vs LCG-2 • Intended to replace LCG-2 • Starts with existing components • Aims to address LCG-2 shortcoming and advanced needs from applications (in particular feedback from DCs) • Prototyping short development cycles for fast user feedback • Initial web-services based prototypes being tested with representatives from the application groups 5
VDT EDG . . . AliEn LCG . . . Approach • Exploit experience and components from existing projects • AliEn, VDT, EDG, LCG, and others • Design team works out architecture and design • Architecture: https://edms.cern.ch/document/476451 • Design: https://edms.cern.ch/document/487871/ • Feedback and guidance from EGEE PTF, EGEE NA4, LCG GAG, LCG Operations, LCG ARDA • Components are initially deployed on a prototype infrastructure • Small scale (CERN & Univ. Wisconsin) • Get user feedback on service semantics and interfaces • After internal integration and testing components to be deployed on the pre-production service 6
Computing Element • Works in push or pull mode • Site policy enforcement • Exploit new Globus GK and Condor-C (close interaction with Globus and Condor team) CEA … Computing Element Acceptance JC … Job Controller MON … Monitoring LRMS … Local Resource Management System 9
Data Management • Scheduled data transfers (like jobs) • Reliable file transfer • Site self-consistency • SRM based storage 10
Replica Catalog Site A Replica Catalog Site B LFN LFN GUID GUID SURL SURL SURL SURL Catalogs • File Catalog • Filesystem-like view on logical file names • Keeps track of sites where data is stored • Conflict resolution • Replica Catalog • Keeps information at a site • (Metadata Catalog) • Attributes of files on the logical level • Boundary between generic middleware and application layer Metadata Catalog Metadata File Catalog GUID Site ID LFN Site ID 12
Job wrapper Job wrapper Job wrapper MPP MPP MPP DbSP Information and Monitoring • R-GMA for • Information system and system monitoring • Application Monitoring • No major changes in architecture • But re-engineer and harden the system • Co-existence and interoperability with other systems is a goal • E.g. MonaLisa e.g: D0 application monitoring: MPP – Memory Primary Producer DbSP – Database Secondary Producer 13
Security CredentialStorage myProxy Obtain Grid (X.509)credentials for Joe PseudonymityService (optional) 1. “Joe → Zyx” 2. tbd 3. AttributeAuthority “Issue Joe’sprivileges to Zyx” 4. Joe VOMS “The Grid” “User=Zyx Issuer=Pseudo CA” GSI LCAS/LCMAPS 14
GAS & Package Manager • Grid Access Service (GAS) • Discovers and manages services on behalf of the user • File and metadata catalogs already integrated • Package Manager • Provides application software at execution site • Based upon existing solutions • Details being worked out together with experiments and operations 15
WMS AliEn TaskQueue, EDG WMS, EDG L&B (CNAF) CE (CERN, Wisconsin) Globus Gatekeeper, Condor-C, PBS/LSF , “Pull component” (AliEn CE) WN 23 at CERN + 1 at Wisconsin SE (CERN, Wisconsin) External SRM implementations (dCache, Castor), gLite-I/O Catalogs (CERN) AliEn FileCatalog, RLS (EDG), gLite Replica Catalog Data Scheduling (CERN) File Transfer Service (Stork) Data Transfer (CERN, Wisc) GridFTP Metadata Catalog (CERN) Simple interface defined Information & Monitoring (CERN, Wisc) R-GMA Security VOMS (CERN), myProxy, gridmapfile and GSI security User Interface (CERN & Wisc) AliEn shell, CLIs and APIs, GAS Package manager Prototype based on AliEn PM Current Prototype 16
Summary, plans • Most Grid systems (including LCG2) are batch-job production oriented, gLite addresses distributed analysis • Most likely will co-exist, at least for a while • A prototype exists, new services are being added: • Dynamic accounts, gLite CEmon, Globus RLS, File Placement Service, Data Scheduler, fine-grained authorization, accounting… • A Pre-Production Testbed is being set up • more sites, tested/stable services • First release due end of March 2005 • Functionality freeze at Christmas • Intense integration and testing period from January to March 2005 • 2nd release candidate: November 2005 • May: revised architecture doc, June: revised design doc 17