1. gLite Information System
Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting
Hassina Beggar – CERIST
Rabat, 6-15 June 2011
Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

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

3. Introduction
Introduction

4. gLite Components

5. 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
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Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

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

7. 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
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Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

8. Background

9. 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
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Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

10. 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)
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Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

11. 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
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ou=Algeria
Cn=Hassina Beggar
Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

12. BDII
BDII

13. GRISs, local BDII and BDII
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Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

14. gLite IS Architecture variare
Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

15. 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
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Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

16. 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
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17. 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
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18. 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.
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19. 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.
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20. Monitoring

21. Monitoring Several centralised monitoring systems avialable
Official monitoring are:
Nagios managed by CERN at
Gstat managed by CERIST and GARR at
Grid Reat Time Monitoring by Imperial College London at
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Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

22. Nagios
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Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

23. GStat
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Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

24. GStat
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Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

25. Real Time Monitor variare
Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

26. 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
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Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting

27. References gLite documentation LDAP Concepts & Overview
LDAP Concepts & Overview
OpenLDAP community
GLUE Schema Specification version 1.3 Final 27
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28. 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 28
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29. Questions….
Africa Joint EUMEDGRID-Support/EPIKH School for Application Porting