gLite Information System(s)

E-infrastructure shared between Europe and Latin America

gLite Information System(s)

Manuel Rubio del SolarCETA-CIEMATEELA Tutorial, Mérida, 07-10.11.2006

EELA Tutorial, Mérida, 14-16.11.2006


This presentation is based on LCG and gLite manuals and previous EELA tutorials



Outline

• Grid Information Systems Overview• gLite Information Systems• GLUE Schema

– Grid elements

• LCG Information System– Hierarchy– LDAP model

• R-GMA– Overview

– Server Architecture– Consumer-Producer model

– User interfaces

• References



Grid Information Systems Overview

• Collect information of grid resources– Discovering new added resources – Monitoring load and health status

• Publish these information– Periodically updated– Well know data model

• Used by– Users searching a concrete resource– WMS allocating and managing jobs– Other monitoring services



gLite Information Systems

• Basic data model.– Grid Laboratory Uniform Environment (GLUE) Schema.

• Two architectures in glite3– LCG Information System

BDII over Globus MDS. OpenLDAP interface. Preserves LCG-2 compatibility.

– Relational Grid Monitoring Architecture (R-GMA) Based on the GMA standard from the Grid Global Forum Information in SQL relational databases Web Services. Future replacement of LCG IS.



GLUE Schema



GLUE Schema

• A schema of objects and attributes describing Grid resources and its relationships.– Originally a EU-DataTAG and US-iVDGL coordinated effort. – Current participants: EGEE, OSG, Globus and NorduGrid. – A way to describe Grid info

Statically and dynamically supplied Hierarchically represented Independently of the framework (LDAP, XML, SQL…)

• Actual release (1.2) is mapped into– LDAP– XML– Old ClassAd (used by Condor Matchmaking)



Site

A collection of resources owned by the same organization and managed by the same administrator. Contains info on the location, the administrator, the web homepage and so on.

Service

The description of a deployed Web Service. Contains the URI endpoint of the WS, the WSDL document, the list owners and so on.

StorageElement Cluster

1 1 1

*

*

*

Site Element



Cluster

A set of heterogeneous resources. Contains information on shared temporary directories.

SubCluster

A set of similar resources. Contains the number of Logical and Physical CPUs.

1

*

Host

Contains detailed static information of the type of hosts and related installed software. Data deal with the type of CPU architecture, memory sizes, the operating system installed as well as the type of network adapter. Furthermore it contains some information on performance mesures obtained by executing well known benchmark softwares.

Location

Information on installed softwares, their path and version

1

*

ComputingElement

1

*

Cluster Element



ComputingElement

Abstraction of a queue of jobs

Policy

Contains info on configuration policies. MaxWallClockTime, MaxRunningJobs, MaxCPUTime . . .

AccessControlPolicyBase

Set of rules defining access control policy rules

Info

Static information on the resource that deal with the type of Loca scheduler adopted, the default Storage Element and so on.

VOview

View for a given Virtual Organization. Contains authorization details for VO members and the amount of available resources.

State

Dynamic information on the status of this queue such as the number of free CPUs and the Estimated Traversal Time (ETT)

Job

Information on jobs in this queue, its owner, its local and global ID and its status

*

*

Computing Element



LCG Information System



LCG Information System Levels

• Resource level: Grid Resource Information Server (GRIS)– One GRIS on top of each CE, SE, RB, MyProxy (no WNs).

– Sensors and scripts get status of concrete resources statically (e.g. GlueCEUniqueID) or dynamically (e.g. GlueCEStateWaitingJobs)

• Site level: Grid Index Information Server (GIIS) – Compiles all the information of the different GRISes in a site.

– LCG-2 recommends using a BDII instead of a GIIS Improves robustness and stability. Called the site BDII.

• Top level: Berkeley DB Information Index (BDII) – Keeps all Grid information about the VOs (generally only one).

– Stores information from local BDIIs or GIISes in its database.

– Only queries sites that are included in a configuration file.



LCG Information System Hierarchy



A LDAP Model

• Way of collecting info– Pull model (higher level servers periodically query lower level

servers)– All servers are based on LDAP

Inherit hierarchical structure (tree-like) LDAP Data Information Format (LDIF)

• Users get info with– Generic applications

ldapsearch (MDS: 2135 and BDII:2170 ports) Graphical (BDII web; LDAP GUIs) Always can get information about specific resources (maybe more

up-to-date) by querying directly the site BDIIs, GIISes or GRISes.

– Querying VO info with lcg-infosites or lcg-info



LDAP Browser showing BDII Info



Relational-GMA



R-GMA Overview

• Added from EDG Project• Based on the GMA standard from the GGF• Information in SQL relational databases (a DB per VO)• Query syntax is a SQL subset• Simple consumer-producer model• Web Services oriented• CLI and Web user interface• Allows self-logging applications• Future replacement of LCG IS



RGMA Overview

• R-GMA offers a global view of the VO information– In one large relational DB: virtual database.– Registry stores localization tuples (database rows) published by

producers: Standard Tables: CE state in GLUE Schema (by R-GMA-GIN) Applications specific tables (e.g. self-logging with Log4j) Access by SQL queries through a WS interface.

– Always updated Consumers get information directly from the resource Can be cached by a secondary producer from single o multiple

producers to improve access.



R-GMA Server Architecture



R-GMA Server Description

• R-GMA Servers– Server (one or several) – Schema Server (There is one common global schema server for the grid)– Registry Server (one or several) – Browser (shows grid information via web browser)

• R-GMA Clients– Generic Client (generic set of APIs for different languages and CLIs) – Servicetool (used by all services to publish its existence and status)– Site Publisher

Client to publish the existence of a site. Each site must have one R-GMA site publisher.

– GadgetIN (GIN) Client to extract information from MDS and to republish it to R-GMA. used by the CE.

– Data archiver (flexible archiver) Client to make the data that is coming from the R-GMA site-publisher,

servicetool and GIN constantly available. By default the GLUE tables and service tables are archived, however this can be

configured.



R-GMA Servers Per Node Type

– The gLite R-GMA Server should deployed the first as part of a gLite grid, because all services require it to publish service information.

Deployment module Contains Used / included by

R-GMA Server R-GMA server

R-GMA registry server

R-GMA schema server

R-GMA browser

R-GMA site publisher

R-GMA archiver

R-GMA servicetool

MON-box

R-GMA client RGMA client APIs UI, WN, SD

R-GMA servicetool R-GMA servicetool R-GMA server,VOMS, LB, WMS, CE, DC, FTS, FTA, Hydra, I/O-Server,Torque Server

R-GMA GIN R-GMA GadgetIN CE



Registry

Producer Consumer

Store

Loc

atio

n

Look up Location

Execute or Stream data

name ID birth Group

SELECT * FROM people WHERE group=‘HR’

Tom 4 1977-08-20

HR

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.

• Data passes directly from the producer to the consumer: (does not through the registry)

• The user or any user application does not need to know the registry; this will be handled directly by the consumers and producers.



Consumer

Producer 1

Registry

TableName

Value 1 Value2

Value 3 Value 4

TableName

Value 1 Value 2

TableName URL 1

TableName URL 2

• The Consumer will get all the URLs that could satisfy the query.

• The Consumer will connect to all the Producers.

• Producers that can satisfy the query will send the tuples to the Consumer.

• The Consumer will merge these tuples to form one result set.

Producer 2TableName

Value 3 Value 4

Multiple Producers



CPULoad (Producer 3)

CH CERN ATLAS 1.6 19055611022002

CH CERN CDF 0.6 19055511022002


UK RAL CDF 0.3 19055711022002

UK RAL ATLAS 1.6 19055611022002


UK GLA CDF 0.4 19055811022002

UK GLA ALICE 0.5 19055611022002

CPULoad (Consumer)

Country Site Facility Load Timestamp

UK RAL CDF 0.3 19055711022002

UK RAL ATLAS 1.6 19055611022002

UK GLA CDF 0.4 19055811022002

UK GLA ALICE 0.5 19055611022002

CH CERN ALICE 0.9 19055611022002

CH CERN CDF 0.6 19055511022002

Select * from CPULoad



ServiceURI VO type emailContact sitegppse01 alice SE [email protected] RAL

gppse01 atlas SE [email protected] RAL

gppse02 cms SE [email protected] RAL

lxshare0404 alice SE [email protected] CERN

lxshare0404 atlas SE [email protected] CERN

ServiceStatusURI VO type up statusgppse01 alice SE y SE is running

gppse01 atlas SE y SE is running

gppse02 cms SE n SE ERROR 101

lxshare0404 alice SE y SE is running

lxshare0404 atlas SE y SE is running

Result Set (Consumer)

URI emailContact

gppse02 [email protected]

SELECT Service.URI Service.emailContact FROM Service S, ServiceStatus SS WHERE (S.URI= SS.URI and SS.up=‘n’)

Joins



R-GMA user interfaces

• R-GMA CLI

• Web interface



References

• GLUE Schema– http://glueschema.forge.cnaf.infn.it/

• LCG-2 User Guide– https://edms.cern.ch/file/454439//LCG-2-UserGuide.html

• gLite 3.0 User Guide– https://edms.cern.ch/file/722398/1.1/gLite-3-UserGuide.pdf

• R-GMA home page– http://www.r-gma.org/

• R-GMA in EGEE– http://hepunx.rl.ac.uk/egee/jra1-uk/



Questions…

Documents

gLite Information System(s)