The Globus Toolkit

The Globus project was started by Ian Foster and Carl Kesselman from Argonne National Labs and USC respectively.

The Globus toolkit is a bag of services bundled together to enable grid computing.

Globus differentiates between global and local services and does not hide these differences from the application developer.

The Globus Toolkit

Globus offers a set of core services so that it can adapt to a different variety of local environments.

Globus uses the hourglass model for Security, Resource Allocation and Communications

[3]

The Globus Toolkit

Single point of authentication. Resources definition and declaration using a common

language. Locate the necessary resources in the system. Process the request for resources and allocate them. Initialize the computation through-out the system. Provide access to remote datasets and file systems. Allow for computational steering and collaboration of

results and other data. Monitor system resources for failures.

The Globus Toolkit

[1]

Globus

Security Infrastructure

The GSI is based on public key encryption, X.509 certificates, and Secure Socket Layer protocol.

However the basis for implementing the GSI functionality is public key encryption.

The central point about GSI is the “certificate”.

Each user and service has an unique certificate. Users and services are authenticated and identified throughout the Grid using this certificate.

Security Infrastructure

The single sign-on is achieved by establishing a chain of trust which finally reaches the Certificate Authority.

Since the proxy need not be encrytped it is stored on disk without encryption (but has limited time-to-live)

VT – CA http://box177.cc.vt.edu/htdocs-public/

[4]

Metacomputing Directory Service

MDS provides resource information.

MDS provides a coherent system information about the various resources in the system even is they are across organizational boundaries.

MDS uses the Lightweight Directory Access Protocol (LDAP) for providing a uniform way of querying information about Grid components which include but are not limited to :Computational Nodes, Network links, Databases, Scientific Instruments, Software Environment, etc.

Grid-info-searchhn=cahuilla.cs.vt.edu, dc=cs, dc=vt, dc=edu, o=Gridobjectclass=GlobusToplastupdate=Wed Apr 3 17:01:33 GMT 2002ttl=undefinedcanonicalsystemname=mips sgi irix 6.5manufacturer=sgiosname=irixosversion=mips sgi irix 6.5totaldatacache=32 Kbytesphysicalmemorysize=256 Mbytescputype=MIPS R10000 Processor Chip Revision: 2.6fputype=MIPS R10010 Floating Point Chip Revision: 0.0cpucount=1cpuload1=1.37cpuload5=0.33cpuload15=0.12

Resource Management System

High level resource management services sit on top of local resource allocation services.

[5]

Resource Specification Language

RSL provides a common language to describe resources in the Grid. The other components of the Resource Management system of the Globus toolkit manipulate RSL strings to manage resources.

RSL provides the syntax to state complex resource descriptions. RSL is based on “attribute-value” pairs.

Each attribute in RSL is a parameter that can be used to control the behavior of a component in the Resource Management System

Resource Specification Language

+(&(contactHostName=“cahuilla.cs.vt.edu")(count=1)(label="subjob 0")(executable=test)(directory=/home2/akarnik/Globus/test)(stdout="stdout.txt") (stderr="stderr.txt"))(&(contactHostName=“anantham.cs.vt.edu") (count=1)(hosts=10)(label="subjob 1")(executable=test)(directory=/home/jihe/Globus/test) (stdout="stdout.txt") (stderr="stderr.txt") )

Global Access to Secondary Storage

GASS allows users on the Grid to access any remote file system by specifying a URL. The URL can be a HTTP URL or a x-gass URL.

GASS also allows a particular server to be a limited file server for remote jobs initiated by that server.

GASS also does away with logging in every time a file transfer needs to be done.

GASS also defines specialized API for Cache, Client and Server management.

Application

• SETI@Home *@Home• Traditional supercomputing applications

– Weather forecasting, Simulations, Virtual Observatory, etc.

• I-Way Experiment– 17 NPACI Sites, 11 Networks– Supercomputers…Instruments

•Cloud Detection Simulation•Combustion System Modeling

Future

• Development of Environments to allow use of grids

• Advances in network infrastructure

• Global Grid to far away…Organizational level grids in the immediate future

References

• “Grid Book” The Grid : Blueprint for a New Computing Infrastructure

• www.globus.org [1]• The Anatomy of the Grid: Enabling Scalable Virtual

Organizations [2]

• Globus: A Metacomputing Infrastructure Toolkit [3]• A Security Architecture for Computational Grids [4]• A Resource Management Architecture for

Metacomputing Systems [5]