gLite Grid Services Riccardo Bruno (riccardo.bruno@ct.infn.it) INFN Dept. Catania Joint EPIKH/EUMEDGRID Support event in Algiers Africa 3 – Site Admin Tutorial + Remote site inst. Algiers, 27.06.2010

What gLite does? What gLite does not What gLite does Somehow my application just run faster My application can run as long as it needs Users can access to any resource Users can rely of a huge amount of software, libraries What gLite does Provides sharing of resources (CPUs, Storage, Sensors …) Allows the creation of virtual organizations (People,Groups) Applications will run faster only if properly developed and best if thought for Grid environments (Trivial parallelization, MPIs) Provides access to computational/storage/other resources accordingly to defined: Policies and Access rights

Scenario Usage scenario Many users of different organizations geographically ditributed (Virtual Oranizations VOs) requesting high computational and storage capacities, collaborating each other

Scenario Usage scenario Many users of different organizations geographically ditributed (Virtual Oranizations VOs) requesting high computational and storage capacities, collaborating each other Many computational resources (computing power and storage) belongs to different institutions but transparently accessible

gLite Grid gLite Grid System aims to: Integrate Virtualize Manage RESOURCEs and SERVICEs across different VOs The gLite middleware is the set of software packages able to do this www.glite.org

Definitions Computational Resource Job Job Submission The machine where users can execute programs (called jobs), can store or access to stored data in a transparent fashion; no matter where they are located. Job An executable or a batch script that the users want to execute on the Worker Node Job Submission Is the action when the best available computational resource is assigned by the system to the user in order to execute the job.

Overview INTERNET The user joins to a VO EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

Overview INTERNET The user joins to a VO Each VO shares grid resources to other VOs accordingly to several policies. INTERNET EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

Overview INTERNET The user joins to a VO Each VO shares grid resources to other Vos accordingly to several policies. The Grid middleware allow to use and share: “Computing Elements (CE)” “Storage Element (SE)” INTERNET EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

Overview INTERNET The users join to a VO Each VO shares grid resources to other Vos accordingly to several policies. The Grid middleware allow to use and share: “Computing Elements (CE)” “Storage Element (SE)” Plus Additional services to empower the capabilities of the Grid INTERNET EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

Overview COLLABORATION INTERNET The users join to a VO Each VO shares grid resources to other Vos accordingly to several policies. The Grid middleware allow to use and share: “Computing Elements (CE)” “Storage Element (SE)” Plus Additional servicees to empower the capabilities of the Grid Result: COLLABORATION INTERNET EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

Grid Requirements Heterogeneous (OSes, Devs, Apps.) VO Resource Sharing (Management, Security and Accounting) Resource Utilisation (Reservation, Metering, Monitoring and Logging) Job Execution (VO access, QoS, LCM, WFM, SLA) Data Services (Integration, Provisioning, Cataloguing, Metadata) Security (Authentication, Authorisation and Auditing) Administrative Costs (Provisioning, Deployment and Configuration) Scalability Availability (Disaster Recovery, Fault Management) Specific Requirements: (EGEE: HEP, BioMed) https://savannah.cern.ch/support/?group=egeeptf QoS – quality of service LCM – Local Credential Maping WFM – Workflow management system SLA – Service Layer Architecture

gLite - Lightweight Middleware for Grid Computing gLite evolution gLite - Lightweight Middleware for Grid Computing www.glite.org GTK2 Web services based gLite-2 gLite-1 LCG-2 LCG-1 gLite-3 GTK4

gLite Main components services UI: User Interface WMS: Workload management system LB: Logging and bookkeeping service VOMS: Virtual Organization Management service BDII: Information system and MON, (going to be deprecated) CE: Computing element (LCG/gLite) WN: Worker nodes SE: Storage element LFC: File catalog AMGA: Metadata catalog

Components The User Interface (UI) is the user entry point normally considered the user workstation. It is normally considered as a WMS component. The Workload Management System (WMS) its a set of services having the responsability to find the best available computing element where submit user’ jobs in a transparent fashion The Logging and bookkeeping service (LB), keep track of user job execution in terms of statuses: Ready, Scheduled, Waiting, Running, Done The Computing element (CE) is the computational resource, the entry point to a cluster or PCs handled by a job queue management system; in particular: TORQUE, PBS, LSF, CONDOR The Worker Nodes are the machines where jobs are really executed and managed by the CE’ queue management system EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

Components The Information System and Monitoring (IS and MON now deprecated), maintain data related to available grid resources and their health statuses. The Virtual Organization Management service (VOMS) , is the way gLite improves the management of authentication and authorization to the Grid resources. The VOMS allows to their own members to define different access rights to VO’ resources The Storage element (SE) and the File catalogue (LFC), allow to manage Grid files and offer a mechanism to locate them easily for users and jobs. EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

Job life cycle EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

Information system & Monitoring Job Workload Management System gLite services gLite services can be grouped in 5 main high level set of services Grid Access Security Information system & Monitoring Job Workload Management System Data Management

gLite – Grid access Two possibilities: APIs or CLI Built on top of them there exist GridPortals and GUIs EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

gLite Security User authentication is based on X.509 (PKI)‏ Authorized Certification Authorities (CA) can generate user and service certificates who identify univocally people or Grid services in the whole Grid Each Grid service may support or not certificates coming from different CAs To reduce the vulnerabilities the identification of users in to the grid is done through the use of proxy certificates. Proxyes are singed ‘copies’ of the original user certificate, having a limited lifetime. The use of Proxy certificates allows the following: Delegation: Any grid service can operates on the user behalf making signed copies of the original proxy. (Single Sign On) Add additional info (Add VO specific information provided by VOMS)‏ Store a long term proxy on a secure server (MyProxy) Renewal (A Proxy close to the expiration time can be automatically renewed)‏

gLite Security: AutH/AhtZ Authentication The user receive a certificate from a CA (PKI third party) He connects to the UI via SSH He Creates the proxy (single sign on) – All grid services will use this proxy to identify the user. Authorization The user has to subscribe to a VO (VOMS) The VO establishes the user rights In any Grid service it will be verified if the user belongs to the VO and assigns the proper access rights to the user A special configuration file named the “gridmapfile”, maintains the correspondency between grid users and resource users (unix pool accounts)

VOMS Virtual Organization Membership Service Manages many Virtual Organizations (VOs). Multiple user roles can be defined inside each VO Extends the X509 schema Extensions are Digitally Signed Service maintenance provided by a web front-end Support MyProxy (stored proxies) Allow the access rights by VO or by Role Each Grid site associates to each VO member or role a a local authentication (unix pool accounts)‏. Allows to implement fine grained security policies to grid resources EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

VOMS MyProxy Stores a long term proxy certificates to allow the automatic proxy renewal mechanism Allow to execute jobs requesting a computation time larger that the normal proxy liferime (normally 12 hrs) The WMS is the responsable of the proxy renewal Users should not use long lived proxy directly Allow the user to access grid resources without carrying out the public and private keys. Proxy Delegation EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

Information Systema and Monitoring Berkeley Database Information Index (BDII) The information hierarchically stored via tree modeling (The LDAP implementation of GLUE) GRIS Stores information at resource level Site BDII/GIIS(deprecated) Stores information at site level BDII Stores information at VO level VO Level Site Level Resource Level To change: View -> Header and Footer

Two core components of WMS Workload Management WMS set of middleware components responsible of distribution and management of jobs across Grid resources. Two core components of WMS WM: accepts and satisfy requests for job management. (Matchmaking) is the process of assigning the best available resource. Logging & Bookeeping : keeps track of job execution in term of events: (Submitted, Running, Done,...)

Computing Element Service that represents the computing resource that is responsible of to manage the queue of jobs to execute The CE may be used by a Generic Client: an end-user interacting directly with the Computing Element, or by the Workload Manager, which submits a given job to an appropriate CE found by the matchmaking process. Two job submission models : PUSH (Eager Scheduling) (jobs pushed to CE), PULL (Lazy Scheduling) (jobs coming from WMS when CE has free slots)

Computing Element: Architecture CEA Computing Element Acceptance JC Job Controller MON Monitoring LRMS Local Resource Management System EELA-2 Tutorial in Cuenca, Ecuador. Universidad de Cuenca, 02/02/2010 - 06/02/2010

Data are stored on Disk Pool Servers or Mass Storage Systems Storage Element SE Services are at least: Storage back-end (Drivers and Hardware) Storage Resource Manager (SRM) Interface (Interface to manage the specific storage solution: dpm, rfio, …) Transfer service (Protocols: GridFTP(gsiftp), glubus-url-copy, …) Native POSIX like file I/O API (GFAL) Auxiliary Accounting and Logging services (accounting: SAGE) Data are stored on Disk Pool Servers or Mass Storage Systems

LFC File Catalog OS like file access metaphor. LFN (Logical file name) GUID (Grid unique identifier) SimLinks SURL (Site URL) TURL (Transfer URL)

AMGA – Arda Metadata Grid Application Metadata is data about data On the Grid: information about files Describe files Locate files based on their contents through queries But also makes DB access a simple task on the Grid Many Grid applications need structured data Many applications require only simple schemas Can be modelled as metadata Main advantage: better integration with the Grid environment Metadata Service is a Grid component Grid security Hide DB heterogeneity

Grid Services and their interactions Grid Access User Iinterface Info system Security MyProxy (Normal, Long term) VOMS Job submission WMS Computing Element Worker Node Data management Catalogs Storage elements BDII

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