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(this is currently used as the README file); improve comments
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$Id: shortest_path_redhat7.2.txt,v 1.4 2002/07/18 21:30:21 harris41 Exp $

INSTALLING LON-CAPA ON A REDHAT 7.2/7.3 SYSTEM

Scott Harrison

* Quick Instructions
* Support
* System Requirements
* Strategy
* Testing
* Acknowledgements

Quick Instructions
------------------

PLEASE contact sharrison@users.sourceforge.net if these instructions
do not work.
PLEASE subscribe yourself to the ANNOUNCE MAILING LIST!
Go to http://mail.lon-capa.org/mailman/listinfo/lon-capa-announce 

1. Download the current version of LON-CAPA from
   http://install.lon-capa.org/downloads/
2. tar xzvf loncapa-N.N.tar.gz (where N.N is the current version number)
3. cd loncapa
4. Read the README file (this file).
5. EXECUTE: ./UPDATE
6. EXECUTE: ./TEST

Please follow the instructions that are given
to you by the TEST command.  You will probably
have to make a few changes and continue to run
TEST until all the system-critical steps are
taken care of.

Support
-------

LON-CAPA is a GPL-based project which originally was, and in a
significant sense still is, located at Michigan State University.  
The installation, software versioning, and specification is
currently maintained by the freeware community which includes
the author of this document and more importantly you!

Your interest, questions and suggestions are enthusiastically
invited for the specific development of the GPL code.

We do our best to help get you started with a 100% operational
system.  Please e-mail sharrison@users.sourceforge.net or
helen@lon-capa.org for help with software installation.

Hardware Recommendation
-----------------------

For full-time, classroom usage, an adequate LON-CAPA server
should be/have:

* a multiprocessor machine,
* a CPU speed of 1 gigahertz,
* a gigabyte of memory,
* and at least 40 to 80 gigabytes of hard disk space.

A lesser machine can be used for toying around with LON-CAPA
(LON-CAPA will run for a single user on most any machine).

LON-CAPA servers experience significant peaks of activity
before a homework submission deadline.  To support these critical
peaks of activity, it is strongly advised that LON-CAPA machines
fit the above recommendation.

If thousands of students start accessing the box as a web server,
then you may want to consider more options.  The design of the LON-CAPA
system is to naturally and transparently load-balance on multiple
computer clusters.  So, a simple solution for running an entire
college campus is to just have an adequate plurality of LON-CAPA
servers rather than a single, particularly monstrous server.

We like to think of high web server usage as "a good problem" though.... :)

More Information on Hardware and System Administration
------------------------------------------------------

I find that LON-CAPA works nicely (for development purposes)
on a Pentium II, 20 gigabytes of hard-disk space, 256M RAM,
and 400MHz.  The consensus is though, that this may only
be adequate for a class of a dozen students. 

If you are making a serious investment, we suggest you
join our mailing list by visiting
http://mail.lon-capa.org/mailman/listinfo/lon-capa-users.
By posting to this mailing list, you can learn about what
solutions have worked for others.

LON-CAPA works on any Intel-based RedHat-compatible
hardware.  Unlike other software systems, it works
comparatively well on dusty old crippled machines without
much RAM or processing.

We support Linux OS.  LON-CAPA has been shown to work on Debian,
Mandrake, and RedHat.  Instructions are based on RedHat-centric
installs.  Given the current level of new LON-CAPA feature requests
and frequency of new software versions, we suggest that you stick
with RedHat to reduce high-frequency system administration overhead.

Critical system software: a "strategic" outlook
---------------------------------------------

In this section, issues related to LON-CAPA server software
are discussed.  (The section after this section describes how to test
and fix problems associated with the issues described below.)

In general, you should expect that LON-CAPA "completely overtakes"
a Linux server system.  Using the same LON-CAPA server computer to disseminate
other unrelated services to your institution is not recommended.

*** PERL ***
A LON-CAPA system needs to have all the
necessary perl modules inside /usr/lib/perl5/.

*** RPMs ***
RPMs are the software packages on a RedHat linux system (the standard,
supported operating system for LON-CAPA).  For security reasons, you need
to keep your RPMs up to date.  For security and performance reasons, a
knowledgeable system administrator at your institution should try to have
a reasonably minimal set; e.g. a LON-CAPA server probably does not need the
"pine" RPM (an e-mail client).

*** MYSQL ***
The MySQL database facilitates fast transactions by passing information on
the LON-CAPA server to the world-wide web.  Important point: in order to
prevent problems associated with 1) corrupted database files,
2) database crashes, 3) changing versions of MySQL, and 4) information export
and import, the information in the MySQL database IS NOT AUTHORITATIVE.
In other words, if the MySQL database gets wiped out, YOU HAVE NOT LOST
CRITICAL DATA.  The authoritative data exists on the filesystem and
the MySQL database is dynamically repopulated and refreshed by 
/home/httpd/perl/searchcat.pl.

*** APACHE ***
LON-CAPA expects that conf/loncapa_apache.conf will be the last Apache
configuration file to be processed before launching the httpd server.  This
may interfere with other ways in which you utilize your web server.  For
instance, LON-CAPA requires that httpd run as user=www and group=www.

Testing
-------

The ./TEST command automates five different kinds of tests.

1. Perl

2. MySQL

3. Web Layer

4. File Status

5. RPM Status

Acknowledgements
----------------

Many thanks to Matthew Hall (Michigan State University),
Guy Albertelli (Michigan State University), Felicia
Berryman (Michigan State University), Gerd Kortemeyer
(Michigan State University) and Martin Siegert (Simon
Frasier University) for their responsive feedback regarding
ideas in this document.