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- "archie - An Electronic Directory Service for the Internet"
-
-
-
-
- Peter Deutsch,
- Computing Centre,
- McGill University.
-
- email: peterd@cc.mcgill.ca
-
-
- Introduction
- -------------
-
- Few other areas in the field of computer science hold out
- such promise for significant performance gains in the
- coming years as the field of computer networking.
- While even a single computer allows the user to access and
- process information faster and more accurately than ever
- before, joining large numbers of such computers together
- with the communications tools needed for users to easily
- share information and resources promises the prospect of a
- true "electronic highway" for information exchange unlike
- anything seen to date.
-
- A principal requirement for the creation of this brave new
- world of networked information was the creation of a
- standard set of protocols and communication mechanisms to
- allow users on disparate networks to share information.
- Such mechanisms have allowed the creation of the Internet.
- a global network of networks that now span the globe,
- connecting millions of users on hundreds of thousands of
- computers.
-
- The Internet now connects universities, colleges and other
- centres of learning with commercial research and
- development groups throughout the world. It serves as both
- a live testbed for on-going networking research and a
- daily communications tool for thousands of users in fields
- far removed from networking and computer science. One
- recent survey estimates that the Internet currently has
- over 535,000 attached hosts in over 30 countries, with a
- user community estimated at over three million people.
-
- The existence of this global information service has
- in turn spurred the development of mechanisms for
- locating and exchanging information. Distributed file
- systems, on-line file archiving mechanisms, electronic mail
- and bulletin boards and expert systems for locating
- and accessing technical expertise are all services that
- exist now on the Internet.
-
- The huge size (and continued rapid growth) of the Internet
- offer a particular challenge to systems designers and
- service providers in this new environment. Before a user
- can effectively exploit any of the services offered by the
- Internet community the user must be aware of both the
- existence of the service and the host or hosts on
- which it is available. Adequately addressing this "resource
- discovery problem" is a central challenge for both service
- providers and users wishing to capitalize on the
- possibilities of the Internet.
-
-
- What is the archie service?
- ----------------------------
-
- The archie service is a collection of resource discovery
- tools that together provide an electronic directory
- service for locating information in an Internet
- environment. Originally created to track the contents of
- anonymous ftp archive sites, the archie service is now
- being expanded to include a variety of other on-line
- directories and resource listings.
-
- Users can access an archie server either through
- interactive sessions (provided they have a direct Internet
- connection) or through queries sent via electronic mail
- messages (provided they can at least gateway electronic
- mail messages onto the Internet).
-
- Interactive access to archie may be through a conventional
- telnet session to a machine running an archie server or
- through a program that has been integrated into a larger
- system, such as the Prospero network distributed file
- system. Additional stand-alone clients are now being
- tested and are available over the network.
-
-
- Why use archie?
- ---------------
-
- The existence of the archie service allow those seeking
- information maintained by an archie server to limit their
- network search to a set of questions to a known server.
- The responses in turn offer pointers to specific Internet
- service providers. Once the existence and location of
- specific information or services has been determined using
- archie, traditional networking tools can be used for final
- access.
-
- Programs have already been created that integrate an
- archie client with the ftp file transfer program or into
- larger information access services. This allows a user to
- first locate and then access information from archie sites
- using a single program.
-
-
- The archie Service Today
- --------------------------
-
- Currently, archie tracks the contents of over 800
- anonymous ftp archive sites containing some 1,000,000
- files throughout the Internet. Collectively, these files
- represent well over 50 Gigabytes (50,000,000,000 bytes) of
- information, with additional information being added daily.
- Anonymous ftp archive sites offer software, data and other
- information that can be copied and used without charge by
- anyone with connection to the Internet.
-
- The archie server automatically updates the listing
- information from each site about once a month, ensuring
- users that the information they receive is reasonably
- timely, without imposing an undue load on the archive
- sites or network bandwidth.
-
-
- The "whatis" database
- -----------------------
-
- In addition to offering access to anonymous ftp listings,
- archie also permits access to the "whatis"
- description database. This database is a collection of
- descriptions that includes the name and a brief synopsis
- for over 3,500 public domain software packages, datasets
- and informational documents located on the Internet.
-
- Additional "whatis" databases are scheduled to be added in
- the coming months. Planned offerings include listings for
- the names and locations of on-line library catalogue
- programs, the names of publicly accessible electronic
- mailing lists and compilations of Frequently Asked
- Questions lists and archive sites for the most popular
- Usenet "newsgroups" or bulletin boards. Suggestions for
- additional descriptions or locations databases are
- welcomed and should be sent to the archie developers at
- "archie-l@archie.mcgill.ca".
-
- Service providers are also encouraged to send in details of
- their offerings to the archie maintainers so that the
- server tracking software can be configured to
- automatically perform updates when site information
- changes. An automatic registration mechanism has also been
- proposed that would allow service providers to make their
- service available without human intervention. This feature
- is expected to be integrated into an upcoming release.
-
-
- Using archie
- -------------
-
- Users with direct Internet connectivity can try out an
- interactive archie server using the basic "telnet" command
- (available at most sites). To use, telnet to the host
- "archie.mcgill.ca" [132.206.2.3] and login as user
- "archie" (there is no password needed). A banner message
- giving latest developments and information on the archie
- project will be displayed and then the command prompt will
- appear. First-time users should try the "help" command to
- get started.
-
- Users with only email connectivity to the Internet should
- send a message to "archie@archie.mcgill.ca", with the
- single word "help" in either the subject line or body of
- the message. You should receive back an email message
- explaining how to use the email archie server, along with
- details of an email-based ftp server operated by Digital
- Equipment Corporation that will perform ftp transfers
- through email requests.
-
- Demo archie clients are stored on archie.mcgill.ca in the
- subdirectory "archie/clients" and may be obtained using
- anonymous ftp. There are several such clients and others are
- currently being tested. Additional work is planned in
- this area in the coming months and details will be announced
- in the archie banner message displayed on login.
-
- Documentation for the archie system is still limited, but
- what there is is also available for anonymous ftp from the
- same host under the directory "archie/pub".
-
-
- Miscellaneous Information
- --------------------------
-
- The archie service began as a project for students and
- volunteer staff at the McGill University School of Computer
- Science. It is now offered as a network resource by a
- number of sites. At the time this article was prepared,
- archie servers are being operated as "archie.mcgill.ca"
- (by McGill University in Montreal, Canada),
- "archie.funet.fi" (by FUnet in Finland) and "archie.au"
- (by AARnet in Australia). The source to the archie project
- has been distributed to a number of U.S. sites and
- additional North American servers are expected to be
- operational soon.
-
- The archie project continues to grow in part because of
- the feedback and response from users. Suggestions for
- improvements and additional features are especially
- welcome. Please let us know what you think...
-
-
- Contacting the archie people
- -----------------------------
-
- Email addresses:
-
- Please send comments, suggestions and bug reports to
- "archie-l@archie.mcgill.ca". This address reaches the
- implementors of archie.
-
- There is also the "archie-people@archie.mcgill.ca" mailing
- list. This list is for people interested in developments
- and progress of the archie project and is open to all who
- wish to subscribe.
-
-
- Surface mail address:
-
- UNIX Support Group,
- Computing Centre,
- McGill University,
- room 200, Burnside Hall,
- 805 Sherbrooke Street West,
- Montreal, Quebec
- CANADA H3A 2K6
-
-
- Phone: (514) 398-3709
-
-