EGEE-II INFSO-RI-031688 Enabling Grids for E-sciencE EGEE Middleware: gLite Information Systems...

EGEE-II INFSO-RI-031688

Enabling Grids for E-sciencE

www.eu-egee.org

EGEE Middleware:gLite Information Systems (IS)

EGEE Tutorial

23rd APAN Meeting, Manila

Jan 22, 2007

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Agenda

• Introduction• LDAP• Glue Schema• IS Components

– GRIS– GIIS– BDII

• IS Query Tools• IS Practical

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Overview of gLite Middleware

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How is Information Systems Used?

If you are a middleware developer

Workload Management System:Matching job requirements and Grid resources

Monitoring Services:Retrieving information about Grid Resources status and availability

If you are a user

Retrieve information about resources• where you can run your job• where you can copy your files

If you are site manager or service

You “publish” the information about theservices you provide.

What resources are availableto the Grid?• Computing resources• Storage resources• Site and Services

What is their current status?

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gLite: MDS Information System

• gLite adopted the Globus Monitoring and Discovery Service as it’s Information System

• The build blocks include– LDAP protocol as the access protocol– Glue Schema to define the format of the information

• Architecture and Components– GRIS– GIIS– BDII

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Lightweight Directory Access Protocol

• Network protocol designed for querying and modifying directory services

• Structures directory entries as a tree: Directory Information Tree (DIT)

• Following a path from the node back to

the root of the DIT– a unique name is built (the

DN):“id=pml,ou=IT,or=CERN,st=Geneva, \

c=Switzerland,o=grid”

o = grid (root of the DIT)

c= US c=Switzerland c=Spain

st = Geneva

or = CERN

ou = IT ou = EP

id = pml id=gv id=fdobjectClass:personcn: Patricia M. L.phone: 5555666office: 28-r019

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LDAP Protocol: the data model

dn: <distinguished name>objectclass:<objectclassname><attributetype>:<attributevalue><attributetype>:<attributevalue>

dn: <distinguished name>objectclass:<objectclassname><attributetype>:<attributevalue><attributetype>:<attributevalue>

This is an entry; collection of

attributes. It’s defined by a unique DN (Distinguished Name)

Objectclass: attribute

• specifies which object class this entry belongs to

• specifies what attributes may or must be defined

• can be used to filter entriesWhite space to

separate entries from each other

Entries, attributes and objectclass names is defined by a

schema

The information is imported and exported by

LDIF files (LDAP Data Interchange Format)

shown above

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The Glue Schema in EGEE/LCG: DIT

DIT for the Computer Resources

DIT for the Storage

Resources

IS data conforms to Glue Schema which provides a common data model to describe Grid resources.http://glueschema.forge.cnaf.infn.it/

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Examples of the Glue Schema

Object classes for CE• Base Class for the CE information (objectclass: GlueCETop)

– No attributes

• CE (objectclass: GlueCE)– GlueCEUniqueID: unique identifier for the CE– GlueCEName: human-readable name of the service

• CE Status (objectclass: GlueCEState)– GlueCEStateRunningJobs: number of running jobs– GlueCEStateWaitingJobs: number of jobs not running– GlueCEStateTotalJobs: total number of jobs (running + waiting)– GlueCEStateStatus: queue status:

queuing (jobs accepted but not running) production (jobs accepted and run) closed (neither accepted nor run) draining (jobs not accepted but those already queued are running)

– GlueCEStateWorstResponseTime: worst possible time between the submission of the job and the start of its execution

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Components of the IS

Top-level BDII: collects information

from GIISs

At each site: a site GIIS (site BDII): collects information from local GRISs

On each resource a GRIS:Publishes dynamic and static information

Abbreviations:

BDII: Berkeley DataBase Information Index

GIIS: Grid Index Information Server

GRIS: Grid Resource Information Server

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CESite GIIS

GRISs, GIISs and BDII connections

SELocal GRIS

LFCLocal GRIS

CELocal GRIS

SELocal GRIS

CE Local GRIS

RBLocal GRIS

MyProxy Local GRIS

SELocal GRIS

CE Local GRIS

CESite GIIS

BDII-A BDII-B

CESite GIIS

User Application

WMS

Monitoring Services

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Querying the IS

Two sets of commands:

• lcg-infosites: simple, meets most needs

• lcg-info: supports more complex queries

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• a user or a service can query– the BDII (usual mode)– LDAP servers on each site

LCG Information Service

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lcg-infosites options

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PRACTICAL

• This introduces use of the commands to access the information system

• You will be exploring the GILDA grid, seeing what computing elements and storage elements exist.

• Please go to the link from this practical.

EGEE-II INFSO-RI-031688 Enabling Grids for E-sciencE EGEE Middleware: gLite Information Systems...

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