dstat-plot: a dstat monitor plotting script

This ruby script uses GNUPlot through a ruby wrapper (ruby_gnuplot) to plot csv data generated by mvneves' dstat-monitor.

Pre-requisites and Installation

You need an installation of the ruby programming language, X11, GNUPlot and the ruby_gnuplot gem. The gems csv and optparse are part of the ruby standard library.

To install on a Mac do the following steps:

1. Install XQuartz from here:
    http://xquartz.macosforge.org/landing/
2. Install gnuplot with homebrew:
    brew install gnuplot --with-x11
3. Install gnuplot gem:
    gem install gnuplot

For linux the procedure is

1. Install gnuplot (your distribution might come with it though)
    sudo apt-get install gnuplot
2. Install gnuplot gem:
    gem install gnuplot
3. Install csv gem
    gem install fastercsv

Usage

Usage:
dstat_plot.rb [options] -c CATEGORY -f FIELD [directory | file1 file2 ...] or
dstat_plot.rb [options] -l COLUMN [directory | file1 file2 ...]
    -v, --verbose                    Output more information
    -i, --invert [VALUE]             Invert the graph such that inverted(x) = VALUE - f(x),
                                     default is 100.
    -n, --no-key                     No plot key is printed.
    -d, --dry                        Dry run. Plot is not saved to file but instead displayed with gnuplot.
    -o, --output FILE|DIR            File or Directory that plot should be saved to.
                                     If a directory is given the filename will be generated.
                                     Default is csv file directory.
    -y, --y-range RANGE              Sets the y-axis range. Default is 105. If a value exceeds
                                     this range, "autoscale" is enabled.
    -t, --title TITLE                Override the default title of the plot.
    -s, --smoothing ALGORITHM        Smooths the graph using the given algorithm.
    -a, --average-over SLICE_SIZE    Calculates the average for slice_size large groups of values.

    -c, --category CATEGORY          Select the category.
    -f, --field FIELD                Select the field.
    -l, --column COLUMN              Select the desired column directly.
    
    -h, --help                       Display this screen.

(-c CATEGORY -f FIELD or -l COLUMN are mandatory parameters)

The plot is saved as category-field.png in the folder where the csv files are located unless -o PATH explicitly specifies a different destination.

Example

ruby dstat_plot.rb -c "total cpu usage" -f "usr" example.csv

The equivalent with the -l option would be

ruby dstat_plot.rb -l 11 example.csv

Possible category - field combinations

(N is the cpu core index for 0..n cores)

Categoriy	Field	Column		Categoriy	Field	Column		Categoriy	Field	Column
epoch	epoch	0		...	sys	12		...	send	24
memory usage	used	1		...	idl	13		net/eth0	recv	25
...	buff	2		...	wai	14		...	send	26
...	cach	3		...	hiq	15		dsk/total	read	27
...	free	4		...	siq	16		...	writ	28
swap	used	5		cpuN usage	usr	17		dsk/sda	read	29
...	free	6		...	sys	18		...	writ	30
system	int	7		...	idl	19		io/total	read	31
...	csv	8		...	wai	20		...	writ	32
paging	in	9		...	hiq	21		io/sda	read	33
...	out	10		...	siq	22		...	writ	34
total cpu usage	usr	11		net/total	recv	23

Smoothing

You can take advantage of a variety of different smoothing algorithms to make your plots more easy on the eye, especially if you're plotting data from a large number of nodes all in one plot.

To do so use the options --smoothing ALGORITHM when running dstat-plot

Available smoothing algorithms are

unique, frequency, cumulative, cnormal, kdensity, unwrap, csplines, acsplines, mcsplines, bezier, sbezier

As an example

ruby dstat_plot.rb -s acsplines -c "total cpu usage" -f "usr" example.csv

will give you the following result