1. gLite Information System
The EPIKH Project
(Exchange Programme to advance e-Infrastructure Know-How)
gLite Information System
Riccardo Rotondo National Institute of Nuclear Physics Asia CHAIN/EU-IndiaGrid2/EPIKH School for Grid Site Administrators Kolkata,

2. Outline Introduction Background LDAP BDII R-GMA Monitoring Conclusion
GLUE Schema
LDAP
BDII
R-GMA
Monitoring
Conclusion

3. Introduction

4. gLite Components

5. gLite Components
worker node

6. 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

7. 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

8. Information Services The gLite Data Model uses GLUE Schema
Two information system available in gLite: BDII and R-GMA
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
The Relational Grid Monitoring Architecture (R-GMA)
is an implementation of the Grid Monitoring Architecture (GMA) standardized by the Open Grid Forum (OGF)
is a relational implementation of the GMA
is strongly Web Service Oriented
variare

9. Background

10. 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

11. 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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12. LDAP Overview Distinguished Name (DN) Attributes Types
Unique name that unambiguously identifies an entry
Es. dn: o=INFN,c=Italy,dc=grid
Attributes Types
dc=grid
(root of the DIT)
c=Italy
c=India
c=Egypt
o=INFN
Meaning
Attribute
Domain Component DC
Country Name C
Organisation Name O
Organisation Unit Name OU
Common Name CN
ou=Roma
variare
ou=Catania
cn=Riccardo Rotondo

13. LDAP Referrals An LDAP server can store a partial DIT
To obtain the DIT all servers need to be linked together
LDAP 1 server
LDAP 2 server
LDAP 3 server
c=USA,dc=example
o=IBM,c=USA,dc=example
dc=example
c=USA
c=USA
o=IBM
o=IT
ou=WEB
variare
referral
referral
All client requests have to start at the global directory LDAP 1

14. BDII

15. GRISs, local BDII and BDII
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16. gLite IS Architecture
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17. The BDII
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18. LDAP Clients BDII servers use standard LDAP protocols
All LDAP client are to access BDII information
Command line of graphical application for every OS are available to access an LDAP server
Ldapsearch –xxx –h [hostname]-p 2170 –b mds-vo-name=local,o=grid
variare

19. JXplorer
variare

20. 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

21. RGMA

22. RGMA overview
R-GMA is based on Grid Monitoring Architecture (GMA) standard defined by the OGF
Implements a Consumer-Producer model
Information are stored in a SQL relation database using a virtual DB per VO
Information are always updated because the consumer get information directly from the provider
Users can query information using a subset of the SQL
Web service oriented
CLI and Web user interface
Relational Grid Monitoring Architecture

23. R-GMA Producer-Consumer Model
The Producer stores its location (URL) in the Registry
The Consumer looks up producer URLs in the Registry
The Consumer contacts the Producer to get all the data or to listen for new data
Data flows directly from the Producer to the Consumer
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24. Monitoring

25. Monitoring Several centralised monitoring systems avialable
Official monitoring are:
Gridmap managed by CERN at
Gstat managed by Academia Sinica at
Grid Reat Time Monitoring byt Imperial College London at
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26. Gridmap
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27. GStat
variare

28. Real Time Monitor
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29. Conclusion

30. Conclusion
Two Information System are provided by gLite: BDII and R-GMA
Information are organised following the GLUE Schema
Users can contact the tob BDII in the hierarchy to get the information of all the resources
Current implemenation use only BDII to check the state of the resources
variare

31. Thank you for your kind attention !
Any question?
Special Thanks to Dr. Marco Fargetta for the material