Interfacing AliEn and ARC Interfacing AliEn and ARC for a - PowerPoint PPT Presentation

Interfacing AliEn and ARC Interfacing AliEn and ARC for a distributed Nordic T1 for a distributed Nordic T1 ● Why such an interface Why such an interface ● ARC and AliEn ARC and AliEn ● The Interface The Interface ● Tests Tests ● Conclusion Conclusion Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 1 1 Philippe Gros – Lund University Philippe Gros – Lund University

Principle Principle NDGF T1 9 sites Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 2 2 Philippe Gros – Lund University Philippe Gros – Lund University

Benefits Benefits ● Operation and Accounting simplification Operation and Accounting simplification – For ALICE: only 1 site For ALICE: only 1 site – For NDGF: only 1 middleware For NDGF: only 1 middleware ● Flexibility Flexibility – Resources can be moved within the Nordic countries Resources can be moved within the Nordic countries – Sites can be easily added at a regional level Sites can be easily added at a regional level Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 3 3 Philippe Gros – Lund University Philippe Gros – Lund University

Requirements of Requirements of an AliEn-ARC interface an AliEn-ARC interface ● From AliEn From AliEn – Works like a normal site Works like a normal site – Simple module in the code (easy to maintain) Simple module in the code (easy to maintain) ● From NorduGrid From NorduGrid – Minimum configuration on sites Minimum configuration on sites (No knowledge of AliEn for site admin) (No knowledge of AliEn for site admin) – Not too much security exception (firewall, privileges...) Not too much security exception (firewall, privileges...) Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 4 4 Philippe Gros – Lund University Philippe Gros – Lund University

ARC middleware ARC middleware ✓ RSL RSL Gatekeeper GridFTP Front-end Cluster Grid Manager Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 5 5 Philippe Gros – Lund University Philippe Gros – Lund University

ARC middleware ARC middleware ● Very active development Very active development – Supported by EU via KnowARC project in 8 countries Supported by EU via KnowARC project in 8 countries Denmark Sweden Norway Hungary Germany Switzerland Slovakia UK Denmark Sweden Norway Hungary Germany Switzerland Slovakia UK – Involved in European Middleware Initiative (EMI) Involved in European Middleware Initiative (EMI) ● Widely deployed Widely deployed – 70+ sites over 12 countries 70+ sites over 12 countries – Almost 70 000 CPUs Almost 70 000 CPUs ● Package Management Package Management – Packages installed by hand by system administartors Packages installed by hand by system administartors – Advertised in Information System with RunTime Environment Advertised in Information System with RunTime Environment Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 6 6 Philippe Gros – Lund University Philippe Gros – Lund University

AliEn Grid Solution AliEn Grid Solution Central Services Mon ALISA Deployed for: API IS File Catalogue Opt. Authen LDAP Task Proxy ISS Transfers Queue Logger Data transfer Manager Opt. Opt. Manager Broker Broker xrootd CM Site Services JA CE xrootd xrootd Mon ~ 70 in ALICE CM CM ALISA … Pack JA CE JA Man Mon Mon ALISA ALISA Pack Pack CE Man Man Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 Pablo.Saiz@cern.ch Oct 24, 2008 7 11/03/10 11/03/10 7 7 Philippe Gros – Lund University Philippe Gros – Lund University

AliEn AliEn ● Specific to the ALICE experiment, also used by e.g. Specific to the ALICE experiment, also used by e.g. FAIR (PandaGrid) FAIR (PandaGrid) ● Development and services centralised at CERN Development and services centralised at CERN ● 40 000 CPUs on over 80 sites 40 000 CPUs on over 80 sites ● Automatic installation of required packages (within Automatic installation of required packages (within ALICE computing framework) ALICE computing framework) ● Jobs pulled by pilots job Jobs pulled by pilots job Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 8 8 Philippe Gros – Lund University Philippe Gros – Lund University

How the interface actually works How the interface actually works Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 9 9 Philippe Gros – Lund University Philippe Gros – Lund University

Interface between AliEn and ARC Interface between AliEn and ARC PackMan checks for available packages on the ARC sites (LDAP query) ARC site Mon ALISA API IS xrootd ARC File Catalogue CM Opt. Authen site LDAP Task Proxy Transfers Mon Queue Logger ALISA Pack CE Manager Opt. Opt. Manager Man Broker Broker ARC site Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 10 10 Philippe Gros – Lund University Philippe Gros – Lund University

Interface between AliEn and ARC Interface between AliEn and ARC The Computing Element checks if there are jobs fitting its capacities Mon ALISA API IS xrootd File Catalogue CM Opt. Authen LDAP Task Proxy Transfers Mon Queue Logger ALISA Pack CE Manager Opt. Opt. Manager Man Broker Broker Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 11 11 Philippe Gros – Lund University Philippe Gros – Lund University

Interface between AliEn and ARC Interface between AliEn and ARC If a package is missing, PackMan sends installation jobs with ARC (“alien login -exec packman install ...”) The job also creates a RTE script to advertise the package in APPS/HEP/ALICE/ Mon ALISA API IS xrootd File Catalogue CM Opt. Authen LDAP Task Proxy Transfers Mon Queue Logger ALISA Pack CE Manager Opt. Opt. Manager Man Broker Broker If the installation job fails, a list of uninstalled packages is created. PackMan will retry the installation regularly (exponential delay) Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 12 12 Philippe Gros – Lund University Philippe Gros – Lund University

Interface between AliEn and ARC Interface between AliEn and ARC The CE sends Job Agents to the sites via ARC. The RTE requirement guaranties that they will only go to sites with the appropriate packages. JA Mon ALISA API IS xrootd JA File Catalogue CM Opt. Authen LDAP Task Proxy Transfers Mon Queue Logger ALISA Pack CE Manager Opt. Opt. Manager Man Broker Broker JA Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 13 13 Philippe Gros – Lund University Philippe Gros – Lund University

Interface between AliEn and ARC Interface between AliEn and ARC The JAs communicate with the Cluster Monitor via SOAP as on normal site. Requires only outbound connectivity from the nodes. JA Mon ALISA API IS xrootd JA File Catalogue CM Opt. Authen LDAP Task Proxy Transfers Mon Queue Logger ALISA Pack CE Manager Opt. Opt. Manager Man Broker Broker The JAs are not allowed to require installation from the PackMan. JA Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 14 14 Philippe Gros – Lund University Philippe Gros – Lund University

Implementation and Installation Implementation and Installation ● AliEn: AliEn: – 2 Perl modules (Submission and PackMan) 2 Perl modules (Submission and PackMan) – Few LDAP parameters Few LDAP parameters ● ARC ARC – Install AliEn (WN installation) Install AliEn (WN installation) – Create RTE script (environment variables) Create RTE script (environment variables) – Allow user with installation privileges Allow user with installation privileges (may need extra plugin for special configuration) (may need extra plugin for special configuration) Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 15 15 Philippe Gros – Lund University Philippe Gros – Lund University

Test Bed in Lund Test Bed in Lund ● Full Central Services Full Central Services ● VO-box on isolated computer VO-box on isolated computer ● Access to 2 ARC sites with special configuration Access to 2 ARC sites with special configuration – LUNARC, Aalborg LUNARC, Aalborg Aalborg Aalborg LUNARC LUNARC Central Services Central Services + VO-box + VO-box Interfacing AliEn and ARC for a distributed Nordic T1 Interfacing AliEn and ARC for a distributed Nordic T1 11/03/10 11/03/10 16 16 Philippe Gros – Lund University Philippe Gros – Lund University