Glossary

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ASC (Astrophysics Simulation Collaboratory): A NSF funded KDI project to establish a common high performance collaborative framework for astrophysicists
Alliance: The National Computational Science Alliance, a nationwide partnership of more than 50 academic, government and bussiness organizations working together on the Grid project
See http://www.ncsa.uiuc.edu/About/Alliance

Base DN: The starting point within the DIT (Directory Information Tree) to perform the search. The DIT organizes objects within a hierarchy. For example, the root DN of the of the ASC GIIS server and the individual GRIS servers that report to it is "o=Grid". So, if one wants to do a browse on any of these machines starting from the root DN he should set up the Base DN as "o=Grid".

Cactus: Application middleware for parallel computation

See http://www.cactuscode.org
CoG Kits (Commodity Grid Kits): A set of services that allow the utilization of the basic Grid services through commodity technologies such as frameworks, environments, and languages. Some examples of these technologies are Java, Perl, and Python.

See http://www.globus.org/cog

Directory: A specialized database designed to retrieve information quickly and securely. It is optimized for read acces because the type of information in the directory is searched often, but changes infrequently.
Directory Information Tree (DIT): The information in the directory is organized in a simple tree structure denoted as the Directory Information Tree (DIT)

GIIS (Grid Information Index Service) server: A central organizational server. The GRIS(Grid Resource information Service) servers run on individual resources and report to their contents to the central GIIS. The central organizational GIIS server of the ASC virtual machine room is giis.ascportal.org.
GIS (Grid Information Service): A service that allows the storage of information about the state of the Grid infrastructure. It publishes information via LDAP protocol. It has the ability to retrieve information asociated with a particular name or it can retrieve a list of categorized entities defined by "object classes". GIS is a general term that also includes the Metacomputing Directory Service(MDS). GIS and MDS are often use interchangeable.

See also http://www.globus.org/mds
Globus: A project that facilitates the creation of usable computational grids.

See http://www.globus.org
GPDK (Grid Portal Development Kit): A set of services for portals built on top of the Java CoG
GRAM (Globus Resource Allocation Manager): Tools for running jobs remotely

See also http://www.globus.org/gram
Grid Certificate: With a Grid certificate one obtains a single sign-on access to all the machines on which he has accounts.
Grids: World wide collections of high performance resources
Grids bring together geographically and organizationally dispersed computational resources such as widely distributed storage systems, computing platforms, instrumentation, and visualization engines.

See also http://www.globus.org/research/testbeds.html
GRIS (Grid Resource Information Service) server: Servers that run on the individual resources and report their contents to the central GIIS
GSI(Grid Security Infrastructure): A set of libraries and tools, provided with the Globus Metacomputing Toolkit, for doing secure authentication over an open network.
GSISSH (GIS-enabled Secure Shell): A SSH program modified to use the GSI libraries and the GSI Certificate for authentication.

See Using the GSI-enabled SSH client
GSIFTP (GIS-enabled FTP): A standard Unix FTP program modified to use the GSI libraries for authentication. It replaces the normal password authentication with Globus certificate authentication.
See http://www.globus.org/datagrid/deliverables/gsiftp-tools.html

Java CoG: Provides access to Grid services through the Java framework.

See http://www.globus.org/cog/java
JSP (Java Server Pages): An extension to servlets. They are used to generate webpage content using XML-like tags and scriptlets written in Java.
See http://java.sun.com/products/jsp

LDAP (Lightweight Directory Access Protocol): A TCP/IP based protocol used to control communication between a user and a directory.

MDS (Metacomputing Directory Service): See GIS
Meta-computing
MPI(Message Passing Interface): The industry-wide standard protocol for passing messages between parallel processors
MPICH-G2: Message Passing Interface for wide-area networks; the Globus version of MPI

See http://www.niu.edu/mpi
MyProxy package: Provides a secure method for portal users to access resources with a limited proxy using the Globus Security Infrastructure (GSI). If the web server is broken into, only the time limited delegated credentials are compromised. The proxy gives you single sign-on capability. While your proxy is active, you can log on into any Grid resource without re-entering your pass-phrase.
MyProxy-pass phrase: A password that protects your Grid Proxy Credential . It is highly recommended you choose a password other than the one you used to generate the private key or Grid Credential.
MyProxy server: The server where your Proxy credential is stored.

NCSA (National Center for Supercomputing Applications): See http://www.ncsa.uiuc.edu/About/NCSA

Portal

RSL (Resource Specification Language): Provides a common language to describe jobs and the resources required to run them. The ASC Portal uses the information it receives from the user and converts them into RSL. Afterwards it contacts the gatekeeper (the machine on which you are running the job) on the remote host and performs mutual authentication. The gatekeeper contacts the job manager service with your request.

Secure server
Servlets: Are similar to java applets that are run on the server side. They are considered to be platform independent and to have improved performance over CGI.
SSL (Secure Sockets Layer): A protocol designed by Netscape Communications to enable encrypted, authenticated communications across the Internet. In an SSL connection each side of the connection must have a security certificate. SSL is mostly used between web browsers and web servers. URL's that begin with "https" indicate that an SSL connection will be used.
Stronghold: A secure SSL Webserver for Unix which allows you to give your Web site full-strength, 128-bit encryption.

TCP/IP(Transmission Control Protocol/Internet Protocol): The suite of communications protocols used to connect hosts to the Internet.
Tomcat: A program that implements Javaservlet and Java Server Pages technologies.

See http://jakarta.apache.org

VMR (Virtual Machine Room): See http://archive.ncsa.uiuc.edu/VMR

Contact kdi_web@wugrav.wustl.edu with comments regarding this page. Last updated Oct. 10, 2001.