RRDGRAPH(1) rrdtool RRDGRAPH(1)
NAME
rrdgraph - Round Robin Database tool graphing functions
SYNOPSIS
rrdtool graph|graphv filename [option ...] [data definition ...] [data calculation ...] [variable
definition ...] [graph element ...] [print element ...]
DESCRIPTION
The graph function of RRDtool is used to present the data from an RRD to a human viewer. Its main purpose is
to create a nice graphical representation, but it can also generate a numerical report.
OVERVIEW
rrdtool graph needs data to work with, so you must use one or more data definition statements to collect this
data. You are not limited to one database, it's perfectly legal to collect data from two or more databases
(one per statement, though).
If you want to display averages, maxima, percentiles, etcetera it is best to collect them now using the
variable definition statement. Currently this makes no difference, but in a future version of RRDtool you may
want to collect these values before consolidation.
The data fetched from the RRA is then consolidated so that there is exactly one data point per pixel in the
graph. If you do not take care yourself, RRDtool will expand the range slightly if necessary. Note, in that
case the first and/or last pixel may very well become unknown!
Sometimes data is not exactly in the format you would like to display it. For instance, you might be
collecting bytes per second, but want to display bits per second. This is what the data calculation command is
designed for. After consolidating the data, a copy is made and this copy is modified using a rather powerful
RPN command set.
When you are done fetching and processing the data, it is time to graph it (or print it). This ends the
rrdtool graph sequence.
Use graphv instead of graph to get detailed information about the graph geometry and data once it is drawn.
See the bottom of the document for more information.
OPTIONS
filename
The name and path of the graph to generate. It is recommended to end this in ".png", ".svg" or ".eps", but
RRDtool does not enforce this.
filename can be '"-"' to send the image to "stdout". In this case, no other output is generated.
Time range
[-s|--start time] [-e|--end time] [-S|--step seconds]
The start and end of the time series you would like to display, and which RRA the data should come from.
Defaults are: 1 day ago until now, with the best possible resolution. Start and end can be specified in
several formats, see AT-STYLE TIME SPECIFICATION and rrdgraph_examples. By default, rrdtool graph calculates
the width of one pixel in the time domain and tries to get data from an RRA with that resolution. With the
step option you can alter this behavior. If you want rrdtool graph to get data at a one-hour resolution from
the RRD, set step to 3'600. Note: a step smaller than one pixel will silently be ignored.
Labels
[-t|--title string] [-v|--vertical-label string]
A horizontal string at the top of the graph and/or a vertically placed string at the left hand side of the
(thumbnail) to use as an icon for use in an overview, for example. All labeling will be stripped off the
graph.
Limits
[-u|--upper-limit value] [-l|--lower-limit value] [-r|--rigid]
By default the graph will be autoscaling so that it will adjust the y-axis to the range of the data. You can
change this behavior by explicitly setting the limits. The displayed y-axis will then range at least from
lower-limit to upper-limit. Autoscaling will still permit those boundaries to be stretched unless the rigid
option is set.
[-A|--alt-autoscale]
Sometimes the default algorithm for selecting the y-axis scale is not satisfactory. Normally the scale is
selected from a predefined set of ranges and this fails miserably when you need to graph something like "260 +
0.001 * sin(x)". This option calculates the minimum and maximum y-axis from the actual minimum and maximum
data values. Our example would display slightly less than "260-0.001" to slightly more than "260+0.001" (this
feature was contributed by Sasha Mikheev).
[-J|--alt-autoscale-min]
Where "--alt-autoscale" will modify both the absolute maximum AND minimum values, this option will only affect
the minimum value. The maximum value, if not defined on the command line, will be 0. This option can be useful
when graphing router traffic when the WAN line uses compression, and thus the throughput may be higher than
the WAN line speed.
[-M|--alt-autoscale-max]
Where "--alt-autoscale" will modify both the absolute maximum AND minimum values, this option will only affect
the maximum value. The minimum value, if not defined on the command line, will be 0. This option can be useful
when graphing router traffic when the WAN line uses compression, and thus the throughput may be higher than
the WAN line speed.
[-N|--no-gridfit]
In order to avoid anti-aliasing blurring effects RRDtool snaps points to device resolution pixels, this
results in a crisper appearance. If this is not to your liking, you can use this switch to turn this behavior
off.
Grid-fitting is turned off for PDF, EPS, SVG output by default.
X-Axis
[-x|--x-grid GTM:GST:MTM:MST:LTM:LST:LPR:LFM]
[-x|--x-grid none]
The x-axis label is quite complex to configure. If you don't have very special needs it is probably best to
rely on the auto configuration to get this right. You can specify the string "none" to suppress the grid and
labels altogether.
The grid is defined by specifying a certain amount of time in the ?TM positions. You can choose from "SECOND",
"MINUTE", "HOUR", "DAY", "WEEK", "MONTH" or "YEAR". Then you define how many of these should pass between each
line or label. This pair (?TM:?ST) needs to be specified for the base grid (G??), the major grid (M??) and
the labels (L??). For the labels you also must define a precision in LPR and a strftime format string in LFM.
between two major grid lines as they specify the complete day and not just midnight.
Y-Axis
[-y|--y-grid grid step:label factor]
[-y|--y-grid none]
Y-axis grid lines appear at each grid step interval. Labels are placed every label factor lines. You can
specify "-y none" to suppress the grid and labels altogether. The default for this option is to automatically
select sensible values.
If you have set --y-grid to 'none' not only the labels get suppressed, also the space reserved for the labels
is removed. You can still add space manually if you use the --units-length command to explicitly reserve
space.
[-Y|--alt-y-grid]
Place the Y grid dynamically based on the graph's Y range. The algorithm ensures that you always have a grid,
that there are enough but not too many grid lines, and that the grid is metric. That is the grid lines are
placed every 1, 2, 5 or 10 units. This parameter will also ensure that you get enough decimals displayed even
if your graph goes from 69.998 to 70.001. (contributed by Sasha Mikheev).
[-o|--logarithmic]
Logarithmic y-axis scaling.
[-X|--units-exponent value]
This sets the 10**exponent scaling of the y-axis values. Normally, values will be scaled to the appropriate
units (k, M, etc.). However, you may wish to display units always in k (Kilo, 10e3) even if the data is in
the M (Mega, 10e6) range, for instance. Value should be an integer which is a multiple of 3 between -18 and 18
inclusively. It is the exponent on the units you wish to use. For example, use 3 to display the y-axis values
in k (Kilo, 10e3, thousands), use -6 to display the y-axis values in u (Micro, 10e-6, millionths). Use a
value of 0 to prevent any scaling of the y-axis values.
This option is very effective at confusing the heck out of the default RRDtool autoscaling function and grid
painter. If RRDtool detects that it is not successful in labeling the graph under the given circumstances, it
will switch to the more robust --alt-y-grid mode.
[-L|--units-length value]
How many digits should RRDtool assume the y-axis labels to be? You may have to use this option to make enough
space once you start fiddling with the y-axis labeling.
[--units=si]
With this option y-axis values on logarithmic graphs will be scaled to the appropriate units (k, M, etc.)
instead of using exponential notation. Note that for linear graphs, SI notation is used by default.
Right Y Axis
[--right-axis scale:shift] [--right-axis-label label]
A second axis will be drawn to the right of the graph. It is tied to the left axis via the scale and shift
parameters. You can also define a label for the right axis.
Force the generation of HRULE and VRULE legends even if those HRULE or VRULE will not be drawn because out of
graph boundaries (mimics behavior of pre 1.0.42 versions).
[--legend-position=(north|south|west|east)]
Place the legend at the given side of the graph. The default is south. In west or east position it is
necessary to add line breaks manually.
[--legend-direction=(topdown|bottomup)]
Place the legend items in the given vertical order. The default is topdown. Using bottomup the legend items
appear in the same vertical order as a stack of lines or areas.
Miscellaneous
[-z|--lazy]
Only generate the graph if the current graph is out of date or not existent. Note, that all the calculations
will happen regardless so that the output of PRINT and graphv will be complete regardless. Note that the
behavior of lazy in this regard has seen several changes over time. The only thing you can really rely on
before RRDtool 1.3.7 is that lazy will not generate the graph when it is already there and up to date, and
also that it will output the size of the graph.
[--daemon address]
Address of the rrdcached daemon. If specified, a "flush" command is sent to the server before reading the RRD
files. This allows the graph to contain fresh data even if the daemon is configured to cache values for a long
time. For a list of accepted formats, see the -l option in the rrdcached manual.
rrdtool graph [...] --daemon unix:/var/run/rrdcached.sock [...]
[-f|--imginfo printfstr]
After the image has been created, the graph function uses printf together with this format string to create
output similar to the PRINT function, only that the printf function is supplied with the parameters filename,
xsize and ysize. In order to generate an IMG tag suitable for including the graph into a web page, the command
line would look like this:
--imginfo '<IMG SRC="/img/%s" WIDTH="%lu" HEIGHT="%lu" ALT="Demo">'
[-c|--color COLORTAG#rrggbb[aa]]
Override the default colors for the standard elements of the graph. The COLORTAG is one of "BACK" background,
"CANVAS" for the background of the actual graph, "SHADEA" for the left and top border, "SHADEB" for the right
and bottom border, "GRID", "MGRID" for the major grid, "FONT" for the color of the font, "AXIS" for the axis
of the graph, "FRAME" for the line around the color spots, and finally "ARROW" for the arrow head pointing up
and forward. Each color is composed out of three hexadecimal numbers specifying its rgb color component (00 is
off, FF is maximum) of red, green and blue. Optionally you may add another hexadecimal number specifying the
transparency (FF is solid). You may set this option several times to alter multiple defaults.
A green arrow is made by: "--color ARROW#00FF00"
[--grid-dash on:off]
Pick the shape of the color marker next to the label according to the element drawn on the graph.
[-m|--zoom factor]
Zoom the graphics by the given amount. The factor must be > 0
[-n|--font FONTTAG:size:[font]]
This lets you customize which font to use for the various text elements on the RRD graphs. "DEFAULT" sets the
default value for all elements, "TITLE" for the title, "AXIS" for the axis labels, "UNIT" for the vertical
unit label, "LEGEND" for the graph legend, "WATERMARK" for the watermark on the edge of the graph.
Use Times for the title: "--font TITLE:13:Times"
Note that you need to quote the argument to --font if the font-name contains whitespace: --font "TITLE:13:Some
Font"
If you do not give a font string you can modify just the size of the default font: "--font TITLE:13:".
If you specify the size 0 then you can modify just the font without touching the size. This is especially
useful for altering the default font without resetting the default fontsizes: "--font DEFAULT:0:Courier".
RRDtool comes with a preset default font. You can set the environment variable "RRD_DEFAULT_FONT" if you want
to change this.
RRDtool uses Pango for its font handling. This means you can to use the full Pango syntax when selecting your
font:
The font name has the form "[FAMILY-LIST] [STYLE-OPTIONS] [SIZE]", where FAMILY-LIST is a comma separated list
of families optionally terminated by a comma, STYLE_OPTIONS is a whitespace separated list of words where each
WORD describes one of style, variant, weight, stretch, or gravity, and SIZE is a decimal number (size in
points) or optionally followed by the unit modifier "px" for absolute size. Any one of the options may be
absent.
[-R|--font-render-mode {normal,light,mono}]
There are 3 font render modes:
normal: Full Hinting and Anti-aliasing (default)
light: Slight Hinting and Anti-aliasing
mono: Full Hinting and NO Anti-aliasing
[-B|--font-smoothing-threshold size]
(this gets ignored in 1.3 for now!)
This specifies the largest font size which will be rendered bitmapped, that is, without any font smoothing. By
default, no text is rendered bitmapped.
[-P|--pango-markup]
sup Superscript
small Makes font relatively smaller, equivalent to <span size="smaller">
tt Monospace font
u Underline
More details on <http://developer.gnome.org/pango/stable/PangoMarkupFormat.html>.
[-G|--graph-render-mode {normal,mono}]
There are 2 render modes:
normal: Graphs are fully Anti-aliased (default)
mono: No Anti-aliasing
[-E|--slope-mode]
RRDtool graphs are composed of stair case curves by default. This is in line with the way RRDtool calculates
its data. Some people favor a more 'organic' look for their graphs even though it is not all that true.
[-a|--imgformat PNG|SVG|EPS|PDF]
Image format for the generated graph. For the vector formats you can choose among the standard Postscript
fonts Courier-Bold, Courier-BoldOblique, Courier-Oblique, Courier, Helvetica-Bold, Helvetica-BoldOblique,
Helvetica-Oblique, Helvetica, Symbol, Times-Bold, Times-BoldItalic, Times-Italic, Times-Roman, and
ZapfDingbats.
[-i|--interlaced]
(this gets ignored in 1.3 for now!)
If images are interlaced they become visible on browsers more quickly.
[-T|--tabwidth value]
By default the tab-width is 40 pixels, use this option to change it.
[-b|--base value]
If you are graphing memory (and NOT network traffic) this switch should be set to 1024 so that one Kb is 1024
byte. For traffic measurement, 1 kb/s is 1000 b/s.
[-W|--watermark string]
Adds the given string as a watermark, horizontally centered, at the bottom of the graph.
Data and variables
DEF:vname=rrdfile:ds-name:CF[:step=step][:start=time][:end=time]
CDEF:vname=RPN expression
VDEF:vname=RPN expression
You need at least one DEF and one LINE, AREA, GPRINT, PRINT statement to generate anything useful.
When the filename '-' is given, the contents of the graph itself will also be returned through this interface
(hash key 'image'). On the command line the output will look like this:
print[0] = "0.020833"
print[1] = "0.0440833"
graph_left = 51
graph_top = 22
graph_width = 400
graph_height = 100
graph_start = 1232908800
graph_end = 1232914200
image_width = 481
image_height = 154
value_min = 0.0000000000e+00
value_max = 4.0000000000e-02
image = BLOB_SIZE:8196
[... 8196 bytes of image data ...]
There is more information returned than in the standard interface. Especially the 'graph_*' keys are new.
They help applications that want to know what is where on the graph.
ENVIRONMENT VARIABLES
The following environment variables may be used to change the behavior of "rrdtool graph":
RRDCACHED_ADDRESS
If this environment variable is set it will have the same effect as specifying the "--daemon" option on
the command line. If both are present, the command line argument takes precedence.
SEE ALSO
rrdgraph gives an overview of how rrdtool graph works. rrdgraph_data describes DEF,CDEF and VDEF in detail.
rrdgraph_rpn describes the RPN language used in the ?DEF statements. rrdgraph_graph page describes all of the
graph and print functions.
Make sure to read rrdgraph_examples for tips&tricks.
AUTHOR
Program by Tobias Oetiker <[email protected]>
This manual page by Alex van den Bogaerdt <[email protected]> with corrections and/or additions by
several people
1.4.8 2013-05-23 RRDGRAPH(1)
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