RRDGRAPH(1) rrdtool RRDGRAPH(1)NAMErrdgraph - Round Robin Database tool grapher 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 datapoint 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.
OPTIONS
graphv
This alternate version of graph takes the same arguments and performs
the same function. The v stands for verbose, which describes the output
returned. graphv will return a lot of information about the graph using
the same format as rrdtool info (key = value). See the bottom of the
document for more information.
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 behaviour.
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 graph.
Right 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.
[--right-axis-format format-string]
By default the format of the axis lables gets determined automatically.
If you want todo this your self, use this option with the same %lf
arguments you know from the PRING and GPRINT commands.
Size
[-w|--width pixels] [-h|--height pixels] [-j|--only-graph]
[-D|--full-size-mode]
By default, the width and height of the canvas (the part with the
actual data and such). This defaults to 400 pixels by 100 pixels.
If you specify the --full-size-mode option, the width and height
specify the final dimensions of the output image and the canvas is
automatically resized to fit.
If you specify the --only-graph option and set the height < 32 pixels
you will get a tiny graph image (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 behaviour 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
behaviour off.
Gridfitting is turned off for PDF, EPS, SVG output by default.
Grid
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
autoconfiguration 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. LPR defines where each
label will be placed. If it is zero, the label will be placed right
under the corresponding line (useful for hours, dates etcetera).
If you specify a number of seconds here the label is centered on
this interval (useful for Monday, January etcetera).
--x-grid MINUTE:10:HOUR:1:HOUR:4:0:%X
This places grid lines every 10 minutes, major grid lines every
hour, and labels every 4 hours. The labels are placed under the
major grid lines as they specify exactly that time.
--x-grid HOUR:8:DAY:1:DAY:1:86400:%A
This places grid lines every 8 hours, major grid lines and labels
each day. The labels are placed exactly 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 autoscaler 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
fideling 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.
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 behaviour of lazy in this regard has seen several changes over
time. The only thing you can realy 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.
[-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"
[--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"
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 Antialiasing (default)
light: Slight Hinting and Antialiasing
mono: Full Hinting and NO Antialiasing
[-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]
All text in rrdtool is rendered using Pango. With the --pango-markup
option, all text will be processed by pango markup. This allows to
embed some simple html like markup tags using
<span key="value">text</span>
Apart from the verbose syntax, there are also the following short tags
available.
b Bold
big Makes font relatively larger, equivalent to <span size="larger">
i Italic
s Strikethrough
sub Subscript
sup Superscript
small Makes font relatively smaller, equivalent to <span size="smaller">
tt Monospace font
u Underline
More details on
<http://developer.gnome.org/doc/API/2.0/pango/PangoMarkupFormat.html>.
[-G|--graph-render-mode {normal,mono}]
There are 2 render modes:
normal: Graphs are fully Antialiased (default)
mono: No Antialiasing
[-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.
[-g|--no-legend]
Suppress generation of the legend; only render the graph.
[-F|--force-rules-legend]
Force the generation of HRULE and VRULE legends even if those HRULE or
VRULE will not be drawn because out of graph boundaries (mimics
behaviour of pre 1.0.42 versions).
[-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 statement to generate anything. The other
statements are useful but optional. See rrdgraph_data and rrdgraph_rpn
for the exact format.
NOTE: Graph and print elements
You need at least one graph element to generate an image and/or at
least one print statement to generate a report. See rrdgraph_graph for
the exact format.
graphv
Calling rrdtool with the graphv option will return information in the
rrdtool info format. On the command line this means that all output
will be in key=value format. When used from the Perl and Ruby bindings
a hash pointer will be returned from the call.
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.
SEE ALSOrrdgraph 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 <tobi@oetiker.ch>
This manual page by Alex van den Bogaerdt <alex@vandenbogaerdt.nl> with
corrections and/or additions by several people
1.3.8 2009-04-07 RRDGRAPH(1)
