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<h1><center>colplot Help</center></h1>
First and foremost, the focus on this help is on usability and not intended
to be a lesson in how to <a href=http://collectl.sourceforge.net/Playback.html>
generate data in plot format</a>,
how to choose which data to display, how to display it (from a formatting
perspective) or how to interpret the results.
<p><b>The Methodology</b>
<br>
Colplot is not a general purpose plotting package, but rather one intimately tied
into collectl data file formats and naming conventions. Its purpose is to plot data
files within a particular time frame which are all in the same directory,
having no capability to look
in multiple locations. This means if you want to plot data for 2 systems, you need
to put all associated data files in the same directory. The general convention used
is to have a separate directory that just contains plottable data files, but if there
are non-plottable files in that directory colplot will ignore them. However, your life
will be much easier if you limit that directory to plot files.
<p>
Since colplot uses gnuplot to generate the plots and since gnuplot cannot handle
compressed files, you must make sure your plot files are not compressed. If they
are, colplot will ignore them and either not generate any plots or simply generate
plots for those files that aren't compressed.
<p>
Colplot uses the metaphor of a speadsheet to display its plots, the default being rows of
a particular type of a plot and columns of different systems (if only plotting data
of a single type or for a single system this will collapse into a single column).
If you prefer your <i>spreadsheet</i> to be ordered differently, you can change the
arragement with the <i>Display</i> pulldown menu. When geneating plots, colplot will
put data for multiple days into the same plot which can result in a very dense (and
possibly unreadable) plot. Your choices are then to either choose a shorter timeframe
OR to choose a <i>Display</i> that includes the day as one of the sort criteria which
with then generate a separate plot for each day.
<p>
A number of check boxes are provided that allow you to choose individual
plots OR a couple of macros that select all of a particular type. There are many more
plots available to you than have check boxes and these must be chosen by name if you
want to select one of them. To see the full list of available plots simply click on
the <i>Help</i> button next to the <i>Plots by Name(s):</i> field.
<p>
The following section describes all the fields on the colplot form in the order they occur.
<p><b>What is the purpose of <i>Enable Refresh</i>?</b>?
<br>This is a mode in which a plot is redrawn at a user selectable
frequency, specified in seconds, resulting in pseudo-real time plots.
In conjunction with <i>refresh</i> one can either select a time scale or
request the <i>last</i> n-minutes of data be displayed by selecting the
corresponding radio button.
<p>
The key to making this all work is to select files for the
current day that are continuously being updated by <i>collectl</i> in
non-compressed, plottable format (this requires the <i>collectl</i> switches
-P, -F0 and -oz in addition to any other switches you choose). If collectl
is running on a remote machine it can either write its data to a directory
being shared via nfs or one can periodically pull the changing contents of
the file(s) via a tool such as <i>rsync</i>.
<p>
<b>How to select files to plot</b>
<br>Plot files are selected by using a combination of the <i><b>From/Thru</b></i>
and <i><b>Filename Containing</b></i> fields. On startup, colplot always
examines the currently selected directory, which you can change with the
<i><b>Change Dir</b></i> button, to make sure there at least
one file containing plottable data. It also makes note of the oldest and
newest files in that directory and sets the
<i><b>Date</b></i> fields to these as default
values. If you do nothing else from a file selection perspective, plots will
be generated for all files in this directory. Naturally you can change the dates
to narrow the scope of which files are selected.
<P>
The second way to narrow the scope is to enter one or more strings, separated by spaces,
into the <i><b>Filenames Containing</b></i> field. In addition you specify whether
</i>any</i> of the strings must be included in a filename (the default)
to select it or if <i>all</i> strings must occurs to select it though this is
typically not necessary.
<p>
Further, if the string contains a <i>[</i>, it is assumed
to be in <i>pdsh</i> format. This is a format for specifying a larger number of hostnames
in a compressed format such as <i>xyz[1-5,10]</i>, which is the equivalent of <i>xyz1, xyz2,
xyz3, xyz4, xyz5</i> and <i>xyz10</i>. In this case the <i>any/all</i> field is ignored
and any files whose hostname portions match will be selected.
<p>
When files are selected for plotting,
each name will be examined to see if it matches any of the selection strings and if
not, will <i>not</i> be selected. You can also use an asterisk as a wild card
character in these fields to indicate any characters can match that portion of the
string. Another way to think of these is as what you might specify in an <i><b>ls</b></i>
command.
<p>TIP - if you want to select a specific file or files, it is
sometimes easier to just specify the unique portion of the hostname and the
date in the <i>Filenames Containing</i> box rather than play with date ranges.
If you want all the hosts for a given date just enter the date portion.
<p>
<b>How to select the time period</b>
<br>No real surprise here. To change the plot time period to something other
than a full day, simply change one or both of the time fields.
<p><b>Plot Type</b>
<br>Normally you need do nothing and you will get the default plot type, which
more often than not is a basic <i>line</i> plot. However you can
choose a type to be applied to all plots from one of:
<i>line, point, stacked line</i> or <i>stacked point</i>.
<p>
<b>Display</b>
<br>It can often be confusing to look at a number of plots across multiple
systems and dates and by default, one plot is generated across multiple dates
if applicable. However, if the dates are far apart (say a week or more), one
can get an x-axis for which all the dates are run together. It may also take a
lot longer to gererate multi-day plots so be careful.
<p>
As described earlier, whether the plots contain single or multiple dates,
a tabular display is presented much like a spreadsheet in which one or more
variables specified by <i>Display</i> is used as the column and
data within the column is sorted by the remaining (if any) types.
Use this field
to change the default (columns organized by system and then grouped by plot).
If one of the types includes the string <i>Day</i> the resultant plots will
only be for a single day.
<p><b>Summary Plots</b>
<br>As the name states, these plots provide reports on summary data.
This is the type
of data you would see when running collectl and selecting
summary data by specifying <i>lower case</i> arguments with the -s switch.
Keep in mind that if data wasn't collected for the plot chosen you
will not get any output!
<p><b>Detail Plots</b>
If the summary plots are based on <i>lower case</i> subsystems, these plots represent the data
collected with <i>upper case</i> switches. By default, you will see one plot for each device
for which data was collected.
When producing plots for multiple systems with different
hardware configurations you may see a different number of detail plots.
<p><b>Detail Filters</b>
<br>Sometimes you are only interested in the details of a particular device or perhaps a subset of
them. If so, enter one or more strings into this field to select those devices you are
interested in. For example, if you were to enter <i>eth c1</i> and chose details for networks
and disks, you might see reports for <i>eth0 eth1 eth2 c1d0 c1d1</i>.
<p><b>Plots By Names</b>
<br>There are a number of additional plots that are available to you that are simply too
numerous, and less common, to list on the main page. To see a complete list of these click
on the associated <i>Help</i> button. You may enter one or more of these and they will be
produced in addition to those that may have been selected elsewhere.
<p><b>Changing the destination of the plots</b>
<br>In case you haven't figured it out yet, the plots are generated for display
by gnuplot in png format, but you can also save them as a file or deliver
them using email as a pdf attachment.
The following options allow you to change the way you dispose of your plot(s)
and in what format.
<center>
<table width=80%>
<tr>
<tr>
<td valign=top><b>Email or Dir</b></td>
<td>If this field contains an @, it is assumed to be an email
address, otherwise it is assumed to be a directory name. In
any event, a value in this field directs colplot to generate its output as
a file and either deliver it to the specified email address OR place it in
the specified directory. It is recommended that before using this to first
generate a plot in the format you want and then fill in this field and generate
the plot(s) again.
</td>
</tr>
<tr>
<td valign=top><b>Subject</b></td>
<td>Enter a subject line you would like to see in your email or else
a generic one will be assigned</td>
</tr>
<tr>
<td valign=top><b>Type</b></td>
<td>By default, plots are generated in pdf format (or ghostscript on windows).
Using this field, you can request plots to be generated as png objects, making
it very easy to later include individual plots (rather than a page of plots)
in a document. This field also allows you to tell colplot to not generate any
plots - see <i>Include Ctl File below</i>
<td>
</td>
</tr>
<tr>
<td valign=top><b>Include Ctl</b></td>
<td>For those who wish to take customization of their plots to another level,
checking this box will cause colplot to deliver the gnu control file
to the requested destination.
One can then edit that file to customize various
gnuplot settings not possible through the user interface.
One can then manually
rerun gnuplot, specifying the control file as an argument.
</td>
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</table>
</center>
<p><b>Changing format of the plots</b>
<br>While there are many different options that are simply hardcoded into colplot,
it was decided to expose a handful of the more useful ones through the user interface.
In most cases, you'll never need to change any of these, but it is at least worth
mentioning what they are and what they do:
<center>
<table width=80%>
<tr>
<td valign=top><b>Width</b></td>
<td>This controls the width of the plots as they are displayed. By making this
number larger, you can make the plot significantly wider than a screeen width
and use the horizontal scroll bar to browse through them. The benefit of doing
so is to allow you to look at the data with a finer grain without having to shrink
the time frame.
</td>
</tr>
<tr>
<td valign=top><b>Height</b></td>
<td>This field pretty much works the same as the <i>Width</i> except it controls
height of the plots. It can also be very useful in getting a fine grained look at
data.
</td>
</tr>
<tr>
<td valign=top><b>Thick</b></td>
<td>Make lines or points is scatter plots bigger. This has only been found to work
with gnuplot V4.2.
</td>
</tr>
<tr>
<td valign=top><b>X-Increment</b></td>
<td>By default, gnuplot chooses its own values for the increments on the X-Axis, which
most of the time are quite reasonable. However, there are times when they are not
and this parameter allows you to change that and get an easier to read plot.
</td>
</tr>
<tr>
<td valign=top><b>Legend</b></td>
<td>Legends take up a fair amount of plot real estate and can be removed by
unchecking this box. This can be of value when one wants to line up multiple plots
side by side (which will automatically happen if they are narrow enough - see <i>Width</i>).
</td>
</tr>
<tr>
<td valign=top><b>AdjustHeight</b></td>
<td>Sometimes the combination of the number of lines that appear in a plot and the plot height
can cause a second column of line definitions to appear in the column. If you check this
box the height of an individual plot will be increased if necessary to fit the entire legend
as a single column of names. If you do choose this option not all individial plots may be
the same height. In no circumstances will a plot be shorter that the height specified in the
previous checkbox.
</td>
</tr>
<tr>
<td valign=top><b>PagBrk</b></td>
<td>This option only applies to pdf output (see <i>Type</i> below) and then only when
generating plots for multiple dates or multiple systems. It will cause
a page break every time the date or the system name portion of the file name
changes, making the output easier to read.
</tr>
<tr>
<td valign=top><b>YLog</b></td>
<td>The values for the Y-Axis are generated dynamically, based on the values of
the data. Sometimes a single, high valued value can make the rest of the data
unreadable. Two ways to make more data readable is to plot it logrithmically
and to change the maximum value of the Y Axis. This option does both at the
same time.
</td>
</tr>
<tr>
<td valign=top><b>X-Axis</b></td>
<td>Like the legend, the X-Axis labels take up vertical real estate and can also
be surpressed by unchecking this box. This can be of value (though admittedly
limited) when you want to fit as many plots on the screen at the same time
as possible and still maximize detail.
</td>
</tr>
</table>
</center>
<p><b>Error Messages</b>
<br>There are 2 major kinds of error messages and they will not be discussed in any detail other
than to say some are operational, such as a user trying to select a directory with no
plotting data in it, and some are fatal, such as not configuring the system with
the proper path to gnuplot.
<p>
In any event, if something does go wrong, the user should be informed of what the
problem is and hopefully it will be obvious enough to fix.
<p><b>Command Line Interface</b>
<br>colplot also supports a CLI that exposes all the options available though the web interface.
For more details type <i>colplot -help</i> in a terminal window and if on a
Linux system type you can also type <i>man colplot</i>
for additional information.
<p>
<table width=100%><tr><td align=right><i>updated Feb 21, 2011</i></td></tr></colgroup></table>
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