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Report on CVS Services : Central and LCG-dedicated services

Report on CVS Services : Central and LCG-dedicated services. Sebastian.Lopienski@cern.ch Manuel.Guijarro@cern.ch CERN IT/PS/UI May 2004. Outline. Overview Projects What do they offer? Architectures Advantages Drawbacks Implementation Figures Problems Future.

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Report on CVS Services : Central and LCG-dedicated services

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  1. Report on CVS Services:Central and LCG-dedicated services Sebastian.Lopienski@cern.ch Manuel.Guijarro@cern.ch CERN IT/PS/UI May 2004

  2. Outline • Overview • Projects • What do they offer? • Architectures • Advantages • Drawbacks • Implementation • Figures • Problems • Future

  3. CERN CVS Services Overview • hosting CERN-related software projects • Central CVS service: created following a service request • collection of user requirements • architecture proposals • implementation based on assigned resources • in production since 08/2002, 71 projects and 12GB of data • LCG dedicated CVS service: requested not to rely on AFS • aligns, as much as possible, with Central CVS service setup • in production since 02/2004, 22 projects and 1.5GB of data

  4. CERN Central CVS Service Projects

  5. CERN CVS Services What do they offer? • data integrity (mirror every hour, daily archiving) • several access methods: Kerberos IV, SSH, pserver • automatic CVS lock monitoring and reporting • good performance • web user interfaces (CVSWeb, ViewCVS, Bonsai); • administration tools: Project creation, Access restrictions, • service support (200 Remedy trouble tickets per year + Web documentation) • service monitoring (UIMON, CVS access check, Archiving check,…)

  6. 1 2 N servers repositories Project X ArchitecturesCentral Service vs LCG Service X.cvs.cern.ch

  7. fastest possible access to the repositories (local file system) independent of AFS automatic and transparent load-balancing and fault tolerance (via an ISSCVS DNS alias that distributes CVS requests among a farm of four servers) AdvantagesCentral Service vs LCG Service

  8. dependency on AFS and DNS constant mirroring may affect performance load-balance is on repository level (not request level) slave server down => no fault tolerance fail-over requires human intervention (for the time being) DrawbacksCentral Service vs LCG Service

  9. DNS relocation via ISSCVS ISSCVS: A central service queries some home made metrics in each CVS server Redirects every 30 secs Metrics: SSH  SNMP For more info: V. Bahyl AFS (NFS?) automatic AFS volume resizing (adapt to each repository needs). tools and web interfaces for project relocation (via DNS) CVS domain cvs.cern.ch data replication system (CVSUP) access to repositories and user home directorieson a file-system level via NFS automatic relocation not wanted ImplementationCentral Service vs LCG Service

  10. 71 projects 4 new projects per month Ave. Size= 170MB Top. Size > 4GB less than 12 hours/year downtime 22 projects Not growing Ave. Size= 70MB Top. Size > 270MB less than 12 hours/year downtime FiguresCentral Service vs LCG Service

  11. # of projects trend

  12. Not so many problems • disk failures: • some Western Digital 120GB disks models were faulty • backplane installation (less vibration) • computer centre: • refurbishment (relocation of servers) • power cuts • several short network interruptions (mainly at non-working hours) • partial interruptions: CERN firewall, AFS problems - affecting only some users

  13. Future • provide Kerberos V access (CERN soon ready) • slave server relocation for LCG • hardware update (some nodes are 5 years old) • automatic detection of inactive projects • migrate monitoring from UIMON->Lemon • ¾ of service manpower will disappear => no more dev.

  14. Thank you! Any questions? More information at: http://cern.ch/cvs http://cern.ch/lcgcvs

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