This capacity planning tool will leverage data collected by the Ganglia monitoring 
tool (http://ganglia.sourceforge.net) and provide a simple tabular web page that 
allows you to quickly identify hot spots and trends among key metrics on your 
various clusters of servers.

The project was born out of an effort at a top 15 website to get a handle on 
their capacity planning needs.  It is in use at several companies today.

Requirements
============

* Ganglia 3.x (assumed that default directories are used: e.g., /var/lib/ganglia/rrds)

* rrdtool (1.2 or higher preferred)

* gnuplot (4.0 or higher preferred)

* apache 1.x or 2.x

* php 5.x (with mysql support)

* [optional] arial.ttf font (typically installed in /usr/share/fonts/truetype)

    Example: sudo apt-get install msttcorefonts
             cd /usr/share/fonts/truetype; ln -s msttcorefonts/arial.ttf


Installation
============

It is assumed that you already have a working Ganglia setup.

1) Install any missing required packages (see Requirements section above).

2) Copy capacity directory to it's permanent home (e.g., /usr/local/capacity).

3) Create mysql database:

    mysql -u root -p < /usr/local/capacity/capacity_db.sql

4) Modify cluster.inc and grab_rrd_data.inc in conf directory to your liking.  The 
   contents of cluster.inc are closely tied to your Ganglia directory structure.  
   Note: the web interface allows you to edit these files as well.

5) Setup apache to serve the php scripts under the html directory. 
   TODO: include sample apache conf.d file.

6) Ensure conf directory is writeable by apache user.  
   e.g., chown -R www-data:www-data /usr/local/capacity/conf

7) Ensure logs directory is writeable by all users (or just the ones running
   grab_rrd_data.php below).
   e.g., chmod 777 /usr/local/capacity/logs

8) Test grab_rrd_data.php (which collects ganglia data into db) in the bin directory:

    cd /usr/local/capacity/bin; php /usr/local/capacity/bin/grab_rrd_data.php

9) If no errors reported in step 6, install cron job:

    cp /usr/local/capacity/capacity.cron /etc/cron.d/capacity
    /etc/init.d/cron reload  # for RHEL/Centos
    service cron reload      # for Debian/Ubuntu

    - OR -

    [edit capacity.cron to your liking, removing the root username, and install
     into your crontab]

10) Once there's data collected, visit the web interface you set up with apache.  You 
    can click on any peak metric to see a graph of that metric over time.  
    Note: trend graphs will obviously only become useful after several 
          days/weeks/months of data is collected. :)

That should be it.

Ross MacKinnon
<mackira@gmail.com>