This chapter provides detailed information about the hardware and software that you would need in order to set up and run an Information Gateway using the ROADS and/or Combine software.

The Systems Requirements Overview chapter gives an introduction to the systems-related issues which managers need to consider when setting up and running an information gateway. This chapter provides more detailed technical information about the specific software and hardware requirements that you will need to meet. It does not consider all the issues raised in that chapter. You are referred to any good UNIX systems administration book for areas not covered in detail here, since security, performance, backing up data and so on are all issues that are relevant to running any network service!

System requirements overview

General requirements

In order to run an information gateway you will need:

1. A machine - a computer running a UNIX-based operating system. Examples are a Sun SPARC machine running Solaris (version 2.5 or higher) or an Intel machine (typical desktop PC) running Linux. A popular information gateway will be accessed concurrently by a large number of end-users, each of whom may be searching the database. This means that it is probably worth spending money on ensuring that you have enough memory. While it is difficult to be definitive about this, because memory requirements will be specific to the operating system and software, you should probably expect to operate with a minimum of 128 Mb memory for any reasonably sized gateway. If you are considering using a PC, then it is a good idea to get the highest specification you can afford.
2. Some disk space - enough disk space to install your operating system, gateway software and Web server software and to hold your database of resource descriptions and any associated index. Assume that you'll need a gigabyte of disk space. You almost certainly won't - but in any case you probably won't be able to buy a machine with less disk space than that anyway!
3. A network connection - an Internet connection. The connection needs to be permanent (obviously!) and to provide enough bandwidth to cope with your expected number of end-users. Again, it is very difficult to be specific about this.

Don't forget about issues such as software and hardware support (and the fact that they may cost money) and think about what you are going to do when something breaks. Think about backing up your software, configuration and data. You may need a local tape drive for this or, if your organisation supports it, there may be a centralised archiving facility which you can take advantage of.

ROADS requirements

On top of the general requirements listed above, the current release of the ROADS software (version 2) requires:

• Perl 5.002 or above (5.004 or the latest stable version of Perl 5 is recommended)
• an HTTP daemon which supports the Common Gateway Interface (CGI) specification, for example the Apache Web server. It is recommended that you use Apache, as ROADS version 3 takes advantage of mod-perl to improve its search performance

In order to run the link checking tool and its associated report generator, you will need 'libwww-perl-5', which may be obtained from CPAN.

R E M E M B E R In theory, most of ROADS can be made to run under the Microsoft NT operating system (using the GNU-Win32 toolkit from Cygnus). However, this may not be straightforward to get working and some ROADS facilities may simply never work under NT. Furthermore, there is little experience in the ROADS 'community' of using NT. For these reasons it is not recommended.

Combine requirements

For the Combine software, you will need:

• Perl version 5.003 or higher
• the MD5 package (from CPAN)
• the GNU 'gcc' compiler version 2.7.x or higher, complete with g++ front end and C++ libraries
• the Berkeley DB system (fetch and install the latest stable version from Sleepy-Cat Software)
• a decent version of 'make', preferably GNU's
• an HTTP daemon which supports the Common Gateway Interface (CGI) specification, for example the Apache Web server

These are in addition to the general requirements listed above.

CGI - Common Gateway Interface - A standard for running external programs from a World-Wide Web HTTP server. CGI specifies how to pass arguments to the executing program as part of the HTTP request. It also defines a set of environment variables. Commonly, the program will generate some HTML which will be passed back to the browser but it can also request URL redirection. (definition from The Free On-line Dictionary of Computing)
CPAN - Comprehensive Perl Archive Network
DB - database
GNU - The Free Software Foundation's project to provide a freely distributable replacement for Unix.
ILRT - Institute for Learning and Research Technology
ROADS - Resource Organisation and Discovery in Subject-based services - a set of software tools to enable the set up and maintenance of Web based subject gateways.

All Engineering, http://www.lub.lu.se/eel/ae/

Apache, http://www.apache.org/

BerkeleyDB, http://www.sleepycat.com/

Combine, http://www.lub.lu.se/combine/

CPAN, http://www.sn.no/libwww-perl/

Cygnus, http://www.Cygnus.com/

GNU, http://www.gnu.org/

Linux, http://www.linux.org/

Perl, http://www.perl.com/

ROADS, http://www.ilrt.bris.ac.uk/roads/

Sleepy-Cat Software, http://www.sleepycat.com/

SOSIG, http://www.sosig.ac.uk/

AE. Frisch, Essential System Administration (2nd ed.) (ISBN: 1-56592-127-5)

M. Loukides, System Performance Tuning (ISBN: 0-937175-60-9)

Chapter author : Andy Powell

With contributions from: Paul Hollands