gLite Information System Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting Hassina Beggar – CERIST h.beggar@dtri.cerist.dz Rabat, 6-15 June 2011 Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

Outline Introduction Background LDAP BDII Monitoring Conclusion GLUE Schema LDAP BDII Monitoring Conclusion Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

Introduction Introduction

gLite Components

The Information System What? System to collect information on the state of resources Why? To discover resources of the grid and their nature To check for health status of resources To provide data in order to manage the workload more efficiently How? Monitoring and publishing fresh data on the state of resources Adopting a well known data model variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

Who and how use the IS Users Site Managers Middleware variare Retrieve information about resources: Where can I run my job? Where can I store my files? Which software packages are available on a give CE? Site Managers Publish information about the resources and services they provide Middleware WMS: matching job requirements and allocating the resources Monitoring Services: retrieving information about the status and availability of resources variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

Information Services The gLite Data Model uses GLUE Schema Information system available in gLite: BDII The Berkeley DB Information Index (BDII) has been the LCG middleware Information System provider is an evolution of Globus Meta Directory System (MDS) is based on Lightweight Directory Access Protocol (LDAP) servers variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

Background

Why an Information schema is required? Resources are heterogeneous, geographically dispersed and span multiple trust domains Resources can be dynamically contributed by different owner institutions a precise and shared description of resources among information consumers and resource providers is necessary The same resources description has to be readable from different Grid infrastructures to allow interoperability among them variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

LDAP Overview It is a protocol that defines the method by which directory data is accessed Optimized for reading, browsing and searching information (write-once-read-many-times service) Data is represented as a hierarchy of objects (entities) forming a tree structure Data Information Tree (DIT) variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

LDAP Overview Distinguished Name (DN) Attributes Types Unique name that unambiguously identifies an entry Exemple: dn: o=INFN,c=Italy,dc=grid Attributes Types dc=grid (root of the DIT) c=Algeria c=Morocco c=Italy o=CERIST Meaning Attribute Domain Component DC Country Name C Organisation Name O Organisation Unit Name OU Common Name CN ou=Roma variare ou=Algeria Cn=Hassina Beggar Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

BDII BDII

GRISs, local BDII and BDII variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

gLite IS Architecture variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

LDAP Overview gLite provides several tools to manage the IS Two gLite commands in the UI for the IS queries: lcg-infosites: shows some information related to a Grid component lcg-info: supports complex queries to retrieve more specific information variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

lcg-infosites In this section, two higher level tools will be presented: lcg-infosites and lcg-info. These tools should be enough for most common user needs and will usually avoid the necessity of raw LDAP queries. The lcg-infosites command is actually just a perl script wrapping a series of LDAP commands and was developed to allow users to retrieve information on Grid resources for the most common cases Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting 16

Praticals: lcg-infosites USAGE: lcg-infosites --vo options -v --is -h/--help: help option --vo: VO name (mandatory) --is: it's possible to specify a not default Top BDII Some options: se: The names of the SEs supported by the user's VO ce: The information relative to number of CPUs, running jobs,etc. tag: The names of the tags relative to the software installed in site is printed together with the corresponding CE closeSE: The names of the CEs where the user's VO is allowed to run together with their corresponding closest SEs are provided Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting 17

lcg-info The lcg-info command can be used to list either CEs or the SEs that satisfy a given set of conditions on their attributes, and to print, for each of them, the values of a given set of attributes. The information is taken from the BDII specified by the LCG GFAL INFOSYS environment variable or in the command line. Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting 18

Praticals: lcg-info -h/--help: to see the help USAGE: lcg-info [--list-ce | --list-se] [--query ] [--attrs ] -h/--help: to see the help –list-attrs: print the list of the possible attributes --list-ce: lists the CEs which satisfy a query, or all the CEs if no query is given. --list-se: lists the SEs which satisfy a query, or all the SEs if no query is given. --bdii: allows to specify a BDII in the form <hostname>:<port>. If not given, the value of the environmental variable LCG_GFAL_INFOSYS is used. If that is not defined, the command returns an error. --vo: restricts the output to CEs or SEs where the given VO is authorized. Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting 19

Monitoring

Monitoring Several centralised monitoring systems avialable Official monitoring are: Nagios managed by CERN at https://nagios.africa-grid.org/nagios/ Gstat managed by CERIST and GARR at http://gstat.eumedgrid.eu/gstat Grid Reat Time Monitoring by Imperial College London at http://rtm.hep.ph.ic.ac.uk variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

Nagios variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

GStat variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

GStat variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

Real Time Monitor variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

Conclusion Information System provided by gLite: BDII Informations are organised following the GLUE Schema Users can contact the top BDII in the hierarchy to get the information of all the resources variare Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting

References gLite documentation LDAP Concepts & Overview http://glite.web.cern.ch/glite/documentation/ LDAP Concepts & Overview http://www.zytrax.com/books/ldap/ch2/ OpenLDAP community http://www.openldap.org GLUE Schema Specification version 1.3 Final http://forge.gridforum.org/sf/go/doc14185?nav=1 27 Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting 27

export LCG_GFAL_INFOSYS=bdii.eumedgrid.eu:2170 HANDS ON Information System BDII (use eumed instead of gilda) If will be necessary enter: export LCG_GFAL_INFOSYS=bdii.eumedgrid.eu:2170 https://grid.ct.infn.it/twiki/bin/view/GILDA/InformationSystems 28 Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting 28

Questions…. Africa 6 2011 - Joint EUMEDGRID-Support/EPIKH School for Application Porting