Globus Grid TutorialPart 3:

Information Services

Goals of this Tutorial

Learn how to use the Globus Metacomputing Directory Service to locate and determine characteristics of resources

Locate resources Where are resources with required

architecture, installed software, available capacity, network bandwidth, etc.?

Determine resource characteristics What are the physical characteristics,

connectivity, capabilities of a resource?

The Need for Information

System information is critical to operation of the grid and construction of applications How does an application determine what

resources are available? What is the “state” of the computational

grid? How can we optimize an application based on

configuration of the underlying system? We need a general information

infrastructure to answer these questions

Using Information forResource Brokering

“10 GFlops, EOS data,20 Mb/sec -- for 20 mins”

MetacomputingDirectoryService

GRAMGRAMGRAM

ResourceBroker

Info service:location + selection

Globus ResourceAllocation Managers

GRAM

ForkLSFEASYLLCondoretc.

“What computers?”“What speed?”“When available?”

“50 processors + storage from 10:20 to 10:40 pm”

“20 Mb/sec”

Examples of Useful Information

Characteristics of a compute resource IP address, software available, system

administrator, networks connected to, OS version, load

Characteristics of a network Bandwidth and latency, protocols, logical

topology Characteristics of the Globus infrastructure

Hosts, resource managers

Information Infrastructure

Provide access to static and dynamic information regarding system components

A basis for configuration and adaptation in heterogeneous, dynamic environments

Requirements and characteristics Uniform, flexible access to information Scalable, efficient access to dynamic data Access to multiple information sources Decentralized maintenance

The GlobusMetacomputing Directory Service

Store information in a distributed directory Directory stored in collection of servers

Directory can be updated by Globus system Other information providers and tools Applications (i.e., users)

Information dynamically available to Tools Applications

Directory Service Functions White PagesWhite Pages

Look upLook up the IP number, amount of memory, and so forth, associated with a particular machine

Yellow PagesYellow Pages FindFind all the computers of a particular class

or with a particular property Tuned for high-volume lookup or search Temporary inconsistencies are considered

okay

The Metacomputing Directory Service

Standard interface and protocol Lightweight Directory Access

Protocol (LDAP) Add gateways and pragmas

Globus specific data model Host-centric representation

Data discovery & update SNMP

MDS Client Library

NIS

NWS

LDAP

LDAP API& represent.

Middleware

Datamodel

…

Application

MDS Components

Standard LDAP server Netscape Directory Server v4

Tools for populating & maintaining MDS Integrated with Globus server release, not of

concern to most Globus users Discover static info, update dynamic info

APIs for accessing & updating MDS contents C, Java, PERL (LDAP API, JNDI)

Various tools for manipulating MDS contents Command line tools, Shell scripts & GUIs

LDAP Directory Service

Lightweight Directory Access Protocol Stripped down version of X.500 DAP protocol Supports distributed storage/access (referrals) Supports replication Becoming de facto standard

Defines: Network protocol for accessing directory contents Information model defining form of information Namespace defining how information is

referenced and organized

Directory Structure

Directory contents What information is stored in directory Group related information into entries

Directory organization Objects organized into tree structure Position of object in tree uniquely names

entry

Entries and Object Classes

Directory entry consists of related set of attributes and values

Entries are typed by their Object Class Object class specifications define

Required and optional attributes Attribute types Single inheritance on object classes

Sample Object Classes

Compute Resources Operating System Memory Hierarchy Health and Status

Network Interfaces IP address Interface types

Performance Data Schedule Jobs CPU Loads Network Traffic

Resource Managers Contact strings Scheduled jobs Free nodes

Software Configuration Version Control Contact information

Organizations People

Object Class SpecificationGlobusHost OBJECT CLASS SUBCLASS OF GlobusPhysicalResource RDN = hn (hostName) CHILD OF { organization } MUST CONTAIN { type:: cis, vendor :: cis, model :: cis, ostype :: cis, osversion :: cis } MAY CONTAIN { networkNode :: dn, totalMemory :: cis, totalSwap :: cis, . . . }

GlobusPhysicalResource OBJECT CLASS SUBCLASS OF GlobusTop RDN = rn (resourceName) MUST CONTAIN { imageObject :: dn } MAY CONTAIN { manager :: dn, provider :: dn, technician :: dn, description :: cis, documentation :: cis }

The Directory Information Tree

Directory entries organized into tree Called Directory Information Tree (DIT) Subtrees can be distributed or replicated

Position in tree uniquely names entry Each object is uniquely determined by its

distinguished name (DN) List of unique attribute names and values

along path from root of DIT to object, e.g.:<hn=sp2.sdsc.edu, ou=SDSC, o=NPACI, o=Globus, c=US>

MDS Data Model

Carl Steve

Switch

Ethernet

Ian Gregor SteveWarren

sunny

hot

IBMSP

dark coldLAN

LANWAN

USC/ISI ANL/MCS

c=US

o=globus

o=USC o=ANL

ou=MCSou=ISI

nn=WAN

cn=Ian

cn=Gregor

cn=Warren

cn=Steve

nn=SP-switch

nn=SP-ether

nn=MCS-lan

hn=sp1.mcs.anl.gov

hn=spN.mcs.anl.gov

hn=cold.mcs…

hn=dark.mcs…

cn=Carl

cn=Steve…

…

……

Physical StructureDirectoryInformationTree

<hn= dark.mcs.anl.gov, ou= MCS, o = Argonne National Laboratory, o = Globus, c = US>

Distinguished Name

MDS Tools

Web-based browsers and displays MDS Object Class Browser MDS Explorer

Various APIs and search tools Translators from “Globus Object Definition

Language” Commented LDIF LDAP schema definition language HTML

MDS Object Class Browser

MDS Access/Update Commands

LDAP defines a set of standard commands

ldapsearch, ldapmodify, ldapdelete, etc. We also define MDS-specific commands

grid-info-search, grid-info-create, grid-info-update, grid-info-remove

Routines to ensure data consistency and to insert metadata

APIs are defined for C, Java, etc.

ldap_search_s, ldap_modify_s, ….

Searching an LDAP Database

grid-info-search [options] filter [attributes]grid-info-search [options] filter [attributes]

Default Default grid-info-searchgrid-info-search options-h mds.globus.org MDS server-p 389 MDS port-b “o=Globus, c=US” search start point-T 30 LDAP query timeout-s sub scope = subtree

alternatives: base : lookup this entry one : lookup immediate children

grid-info-search: “Filter”

Filters allow selection of object based on relational operators (=, ~=,<=, >=) grid-info-search “cputype=*”

Compound filters can be construct with Boolean operations: (&, |, !) grid-info-search “(&(cputype=*)(cpuload1<=1.0))” grid-info-search “(&(hn~=sdsc.edu)(latency<=10))”

Hints: white space is significant use -L for LDIF format

required

Example 1: grid-info-search “(mn~=sdsc.edu)”

cn=sp097.sdsc.edu-loadleveler, ou=SDSC, o=NPACI, o=Globus, c=USobjectclass=GlobusResourceManagercn=sp097.sdsc.edu-loadlevelermn=sp097.sdsc.edu-loadlevelerhn=sp097.sdsc.educontact=sp097.sdsc.edu:754:/C=US/O=Globus/O=NPACI/OU=SDSC/ \ CN=sp097.sdsc.edu-loadlevelerapiversion=0.1apitype=loadlevelermanagedresources=hn=sp097.sdsc.edu, ou=SDSC, o=NPACI, \ o=Globus, c=USgramversion=1.53gramversiondate=1998/06/1921:17:23gramsecurity=ssleayfreenodes=49totalnodes=117lastupdate=Sat Jun 27 18:23:34 GMT 1998scheduledjob=none

Example 2:grid-info-search -L “(sw=Globus)”

dn: sw=Globus, hn=host.domain.edu, o=My Organization, o=Globus, c=USsw: Globusobjectclass: GlobusSoftwarereleasemajor: 1releaseminor: 1releasepatch: 0configuration: --prefix=/cpc/globus/service/sun4-sparc2 \ --with-ssl-path=/cpc/ssl/sun4-sparc2 configuration: --prefix=/cpc/globus/tools/sun4-sparc2 \ --with-ssl-path=/cpc/ssl/sun4-sparc2 installprefix: /cpc/globus/serviceprefix: /cpc/globus/servicetoolsprefix: /cpc/globus/toolsdeployprefix: /opt/globus/userid: globusobjectname: sw=Globus, hn=host.domain.edu, o=My Organization, \ o=Globus, c=USlastupdate: Wed Jan 20, 06:06:13 GMT 1999

grid-info-search: “Attributes”

Projections on the data objects are performed by supplying a list of attributes

Retrieve the DN for all objects in the MDS:% grid-info-search -L “(objectclass=*)” dn

dn: o=Globus, c=US

dn: o=University of Southern California, o=Globus, c=US

dn: ou=MCS, o=Argonne National Laboratory, o=Globus, c=US

dn: o=NASA Ames, o=Globus, c=US

dn: ou=SDSC, o=NPACI, o=Globus, c=US

Multiple Attribute Selection

% grid-info-search -L “(objectclass=*)” dn hn Returns the distinguished name (dn) and hostname

(hn) of all objects

Objects without hn fields are still listed DNs are always listed

dn: o=CalTech, o=Globus, c=US

dn: hn=neptune.cacr.caltech.edu, o=CalTech, o=Globus, c=UShn: neptune.isi.edu

dn: ou=SDSC, o=NPACI, o=Globus, c=US

dn: o=University of Southern California, o=Globus, c=US

Efficient Lookups

Naïve searches retrieve lots of information % grid-info-search “(objectclass=*)” | grep contact

Whenever possible, reduce search domain Specify a search base (-b) % grid-info-search -b “o=NASA Ames, o=Globus, C=US”

Specify the scope of the search (-s)options: base, one, and sub

Narrow the amount of objects selected, i.e., use specialized filters

Specify which attributes you want

Authentication to MDS

Authentication is required to perform certain operations (e.g., write operations)

Each site has a Directory Manager cn=Directory Manager, o=Organization, c=US

Users registered with the MDS have a DN cn=Jane Doe, o=Organization, c=US

% grid-info-search -D “cn=Jane Doe, o=Organization, c=US” \

-w <passwd>

Updating MDS Entries

To update an existing database entry:grid-info-modify -D "cn=Directory Manager, o=Globus, c=US” \

-w <PASSWORD> -f sample.ldif

dn: hn=tuva.mcs.anl.gov, ou=MCS, o=Argonne National Laboratory, o=Globus, c=US

cpuload1: 3.11cpuload5: 2.64cpuload15: 2.57

Metadata is inserted by grid-info-updategrid-info-update -D "cn=Directory Manager, o=Globus, c=US” \

-w <PASSWORD> -f sample.cldif

Example: Discovering CPU Load

Retrieve CPU load fields of compute resourcesgrid-info-search -L “(objectclass=GlobusComputeResource)” \

dn cpuload1 cpuload5 cpuload15 dn: hn=lemon.mcs.anl.gov, ou=MCS, o=Argonne National Laboratory, o=Globus, c=UScpuload1: 0.48cpuload5: 0.20cpuload15: 0.03 dn: hn=tuva.mcs.anl.gov, ou=MCS, o=Argonne National Laboratory, o=Globus, c=UScpuload1: 3.11cpuload5: 2.64cpuload15: 2.57

Exercise 3Extended Exercises

Explore the MDS via MDS object code Browser

http://www.globus.org/mds MDS Navigator

http://www.globus.org/testbeds Globus View

http://www.globus.org/testbeds

Write a set of MDS/LDAP queries% grid-info-search “hn~=isi.edu”

MDS Search Exercises

1. List all hosts that have a “lsf” jobmanager type.

2. List all hosts that have a CPU load greater than 5.

3. List all hosts with 16 or more CPUs.

4. Determine the current versions of Globus installed at Argonne.

5. Determine the deployment directory on flash.isi.edu.

6. Determine the bandwidth between pitcairn.mcs.anl.gov and bolas.isi.edu.

MDS Search Answers (1)

1. List all hosts that have a “lsf” gatekeeper. grid-info-search “apitype=lsf” hostname

2. List all hosts that have a CPU load greater than 5. grid-info-search “cpuload1>=5” hostname

3. List all hosts with 16 or more CPUs. grid-info-search “cpucount>=16” hostname

4. Determine the current versions of Globus installed at Argonne.

grid-info-search \ -b ‘o=Argonne National Laboratory, o=Globus, c=US’ \ ‘sw=Globus’ releasemajor releaseminor releasepatch

MDS Search Answers (2)

5. Determine the deployment directory on flash.isi.edu. grid-info-search \

‘(&(objectclass=*ResourceManager)(hn=flash.isi.edu))’ \ deploydir

6. Determine the bandwidth between pitcairn.mcs.anl.gov and bolas.isi.edu.

grid-info-search \ “(|(&(sourcehostname=pitcairn.mcs.anl.gov) \ (destinationhostname=bolas.isi.edu)) \ (&(sourcehostname=bolas.isi.edu) \ (destinationhostname=pitcairn.mcs.anl.gov)))” bandwidth

Summary

MDS provides the information needed to perform dynamic resource discovery and configuration Critical component of resource brokers

MDS is base on existing directory service standards (LDAPv3)

Changes from 1.0 to 1.1

Tools are renamed

globus-mds-{search,add,delete,modify} became

grid-info-{search,add,delete,modify}

Configurable LDAP search timeout (-T)