Introduction

Globus provides a means for the creation of computational grids and a toolkit of core services with which applications can be developed to access the grid. Two Globus developers, Ian Foster and Carl Kesselman, were awarded the 1997 Global Information Infrastructure (GII) Next Generation Award for their work in advancing the technology and application of high performance distributed computing.

Globus itself provides the following core services:

• Communication services in the form of the Globus-io communication library.
• Resource allocation and process management. This provides a standard interface to local resource management systems, allowing computational grid tools and applications to express resource allocation and process management requests in terms of a standard API and protocol, without constraining individual sites to any specific resource management tool.
• Authentication and related security services. In Globus, a user authenticates just once per session, at which time a credential is generated that allows processes created on behalf of the user to acquire resources, etc., without additional user intervention.
• Provides a standard protocol (LDAP, the Lightweight Directory Access Protocol) for discovering, publishing, and accessing information about the configuration and status of the computational grid. It also provides an extensible data model, application programming interface (API), and tools that use this protocol.
• Monitoring of status of system components. This is comprised of a client interface and a data-collector API. The client interface allows a process to register with the HBM service, which then expects to receive regular "heart beats" from the process. If a heart beat is not received, the HBM service attempts to determine whether the process itself is faulty or whether the underlying network or computer has failed.
• Remote access to files. Through the Global Access to Secondary Storage (GASS) subsystem, remote files can be opened for reading and writing and accessed through standard C I/O calls. Files opened for reading are copied to a local file cache when they are opened, hence permitting subsequent read operations to proceed without communication. Similarly, files opened for writing are created locally and copied to their destination only when they are closed.
• Construction and discovery of executables.

• MPICH-G2 website
• MPICH-G2 performance numbers

The Globus Toolkit is being used by major grid based technologies developers around the world. Some of these include the National Science Foundation's National Partnership for Advanced Computing Infrastructure (NPACI), National Center for Supercomputing Applications (NCSA), the European DataGrid project based at CERN, the NASA Information Power Grid, and the Dept. of Energy's ASCI Grid Services group. Additionally, three large scientific communities have begun building production Grids based on Globus software to serve their researchers: the Grid Physics Network (GriPhyN), the Network for Earthquake Engineering Simulation (NEESgrid), and the Earth Sciences Grid (ESG).

Many scientific applications will not use Globus directly, but through higher-level application frameworks such as MPICH-G2 (Northern Illinois University and Argonne National Laboratory), Condor-G (University of Wisconsin), Nimrod/G (Monash University, Australia), NetSolve (University of Tennessee Knoxville), and PUNCH (Purdue University). Other application frameworks that utilize Globus services include GridPort, Cactus, GrADS, and MPICH-G2.

The images in the left panel come from applications that used Globus  (click on the icon to display the full image in a new window).

Evaluation

Globus has not been evaluated yet, but you can submit your own evaluation of Globus if you would like to.

Status

Globus is now available under an Open Source license. The latest release available for download is 3.2. See Globus services at NERSC for a list of the services available to NERSC users.

Documentation

There are several sources of information about The Globus Toolkit. Here we list only a few:

• Globus Toolkit 3.2 Documentation
• Globus Toolkit 3.0 Documentation
• Globus Tutorials

• PyGlobus: Python-based interface to Globus
• PyGridWare: Python-based implementation of the Open Grid Services Infrastructure
  

Developers

Globus was developed by a large team formed by people from various places.