1 =head1 NAME
3 rrdgraph - Round Robin Database tool grapher functions
5 =head1 SYNOPSIS
7 B<rrdtool graph> I<filename>
8 [I<L<option|rrdgraph/OPTIONS>> ...]
9 [I<L<data definition|rrdgraph_data/DEF>> ...]
10 [I<L<data calculation|rrdgraph_data/CDEF>> ...]
11 [I<L<variable definition|rrdgraph_data/VDEF>> ...]
12 [I<L<graph element|rrdgraph_graph/GRAPH>> ...]
13 [I<L<print element|rrdgraph_graph/PRINT>> ...]
15 =head1 DESCRIPTION
17 The B<graph> function of B<RRDtool> is used to present the
18 data from an B<RRD> to a human viewer. Its main purpose is to
19 create a nice graphical representation, but it can also generate
20 a numerical report.
22 =head1 OVERVIEW
24 B<rrdtool graph> needs data to work with, so you must use one or more
25 B<L<data definition|rrdgraph_data/DEF>> statements to collect this
26 data. You are not limited to one database, it's perfectly legal to
27 collect data from two or more databases (one per statement, though).
29 If you want to display averages, maxima, percentiles, etcetera
30 it is best to collect them now using the
31 B<L<variable definition|rrdgraph_data/VDEF>> statement.
32 Currently this makes no difference, but in a future version
33 of rrdtool you may want to collect these values before consolidation.
35 The data fetched from the B<RRA> is then B<consolidated> so that
36 there is exactly one datapoint per pixel in the graph. If you do
37 not take care yourself, B<RRDtool> will expand the range slightly
38 if necessary. Note, in that case the first and/or last pixel may very
39 well become unknown!
41 Sometimes data is not exactly in the format you would like to display
42 it. For instance, you might be collecting B<bytes> per second, but
43 want to display B<bits> per second. This is what the B<L<data
44 calculation|rrdgraph_data/CDEF>> command is designed for. After
45 B<consolidating> the data, a copy is made and this copy is modified
46 using a rather powerful B<L<RPN|rrdgraph_rpn/>> command set.
48 When you are done fetching and processing the data, it is time to
49 graph it (or print it). This ends the B<rrdtool graph> sequence.
51 =head1 OPTIONS
53 =over 4
55 =item filename
57 The name and path of the graph to generate. It is recommended to
58 end this in C<.png>, C<.svg> or C<.eps>, but B<RRDtool> does not enforce this.
60 I<filename> can be 'C<->' to send the image to C<stdout>. In
61 this case, no other output is generated.
63 =item Time range
65 [B<-s>|B<--start> I<time>]
66 [B<-e>|B<--end> I<time>]
67 [B<-S>|B<--step> I<seconds>]
69 The start and end of the time series you would like to display, and which
70 B<RRA> the data should come from. Defaults are: 1 day ago until
71 now, with the best possible resolution. B<Start> and B<end> can
72 be specified in several formats, see
73 L<AT-STYLE TIME SPECIFICATION|rrdfetch/> and L<rrdgraph_examples>.
74 By default, B<rrdtool graph> calculates the width of one pixel in
75 the time domain and tries to get data from an B<RRA> with that
76 resolution. With the B<step> option you can alter this behaviour.
77 If you want B<rrdtool graph> to get data at a one-hour resolution
78 from the B<RRD>, set B<step> to 3'600. Note: a step smaller than
79 one pixel will silently be ignored.
81 =item Labels
83 [B<-t>|B<--title> I<string>]
84 [B<-v>|B<--vertical-label> I<string>]
86 A horizontal string at the top of the graph and/or a vertically
87 placed string at the left hand side of the graph.
89 =item Size
91 [B<-w>|B<--width> I<pixels>]
92 [B<-h>|B<--height> I<pixels>]
93 [B<-j>|B<--only-graph>]
95 The width and height of the B<canvas> (the part of the graph with
96 the actual data and such). This defaults to 400 pixels by 100 pixels.
98 If you specify the B<--only-graph> option and set the height E<lt> 32
99 pixels you will get a tiny graph image (thumbnail) to use as an icon
100 for use in an overview, for example. All labeling will be stripped off
101 the graph.
103 =item Limits
105 [B<-u>|B<--upper-limit> I<value>]
106 [B<-l>|B<--lower-limit> I<value>]
107 [B<-r>|B<--rigid>]
109 By default the graph will be autoscaling so that it will adjust the
110 y-axis to the range of the data. You can change this behaviour by
111 explicitly setting the limits. The displayed y-axis will then range at
112 least from B<lower-limit> to B<upper-limit>. Autoscaling will still
113 permit those boundaries to be stretched unless the B<rigid> option is
114 set.
116 [B<-A>|B<--alt-autoscale>]
118 Sometimes the default algorithm for selecting the y-axis scale is not
119 satisfactory. Normally the scale is selected from a predefined
120 set of ranges and this fails miserably when you need to graph something
121 like C<260 + 0.001 * sin(x)>. This option calculates the minimum and
122 maximum y-axis from the actual minimum and maximum data values. Our example
123 would display slightly less than C<260-0.001> to slightly more than
124 C<260+0.001> (this feature was contributed by Sasha Mikheev).
126 [B<-M>|B<--alt-autoscale-max>]
128 Where C<--alt-autoscale> will modify both the absolute maximum AND minimum
129 values, this option will only affect the maximum value. The minimum
130 value, if not defined on the command line, will be 0. This option can
131 be useful when graphing router traffic when the WAN line uses compression,
132 and thus the throughput may be higher than the WAN line speed.
134 [B<-N>|B<--no-gridfit>]
136 In order to avoid anti-aliasing effects gridlines are placed on
137 integer pixel values. This is by default done by extending
138 the scale so that gridlines happens to be spaced using an
139 integer number of pixels and also start on an integer pixel value.
140 This might extend the scale too much for some logarithmic scales
141 and for linear scales where B<--alt-autoscale> is needed.
142 Using B<--no-gridfit> disables modification of the scale.
144 =item Grid
146 =over 4
148 =item X-Axis
150 [B<-x>|B<--x-grid> I<GTM>B<:>I<GST>B<:>I<MTM>B<:>I<MST>B<:>I<LTM>B<:>I<LST>B<:>I<LPR>B<:>I<LFM>]
152 [B<-x>|B<--x-grid> B<none>]
154 The x-axis label is quite complex to configure. If you don't have
155 very special needs it is probably best to rely on the autoconfiguration
156 to get this right. You can specify the string C<none> to suppress the grid
157 and labels altogether.
159 The grid is defined by specifying a certain amount of time in the I<?TM>
160 positions. You can choose from C<SECOND>, C<MINUTE>, C<HOUR>, C<DAY>,
161 C<WEEK>, C<MONTH> or C<YEAR>. Then you define how many of these should
162 pass between each line or label. This pair (I<?TM:?ST>) needs to be
163 specified for the base grid (I<G??>), the major grid (I<M??>) and the
164 labels (I<L??>). For the labels you also must define a precision
165 in I<LPR> and a I<strftime> format string in I<LFM>. I<LPR> defines
166 where each label will be placed. If it is zero, the label will be
167 placed right under the corresponding line (useful for hours, dates
168 etcetera). If you specify a number of seconds here the label is
169 centered on this interval (useful for Monday, January etcetera).
171 --x-grid MINUTE:10:HOUR:1:HOUR:4:0:%X
173 This places grid lines every 10 minutes, major grid lines every hour,
174 and labels every 4 hours. The labels are placed under the major grid
175 lines as they specify exactly that time.
177 --x-grid HOUR:8:DAY:1:DAY:1:0:%A
179 This places grid lines every 8 hours, major grid lines and labels
180 each day. The labels are placed exactly between two major grid lines
181 as they specify the complete day and not just midnight.
183 =item Y-Axis
185 [B<-y>|B<--y-grid> I<grid step>B<:>I<label factor>]
187 [B<-y>|B<--y-grid> B<none>]
189 Y-axis grid lines appear at each I<grid step> interval. Labels are
190 placed every I<label factor> lines. You can specify C<-y none> to
191 suppress the grid and labels altogether. The default for this option is
192 to automatically select sensible values.
194 [B<-Y>|B<--alt-y-grid>]
196 Place the Y grid dynamically based on the graph's Y range. The algorithm
197 ensures that you always have a grid, that there are enough but not too many
198 grid lines, and that the grid is metric. That is the grid lines are placed
199 every 1, 2, 5 or 10 units. This parameter will also ensure that you get
200 enough decimals displayed even if your graph goes from 69.998 to 70.001.
201 (contributed by Sasha Mikheev).
203 [B<-o>|B<--logarithmic>]
205 Logarithmic y-axis scaling.
207 [B<-X>|B<--units-exponent> I<value>]
209 This sets the 10**exponent scaling of the y-axis values. Normally,
210 values will be scaled to the appropriate units (k, M, etc.). However,
211 you may wish to display units always in k (Kilo, 10e3) even if the data
212 is in the M (Mega, 10e6) range, for instance. Value should be an
213 integer which is a multiple of 3 between -18 and 18 inclusively. It is
214 the exponent on the units you wish to use. For example, use 3 to
215 display the y-axis values in k (Kilo, 10e3, thousands), use -6 to
216 display the y-axis values in u (Micro, 10e-6, millionths). Use a value
217 of 0 to prevent any scaling of the y-axis values.
219 This option is very effective at confusing the heck out of the default
220 rrdtool autoscaler and grid painter. If rrdtool detects that it is not
221 successful in labeling the graph under the given circumstances, it will switch
222 to the more robust B<--alt-y-grid> mode.
224 [B<-L>|B<--units-length> I<value>]
226 How many digits should rrdtool assume the y-axis labels to be? You
227 may have to use this option to make enough space once you start
228 fideling with the y-axis labeling.
230 =back
232 =item Miscellaneous
234 [B<-z>|B<--lazy>]
236 Only generate the graph if the current graph is out of date or not
237 existent.
239 [B<-f>|B<--imginfo> I<printfstr>]
241 After the image has been created, the graph function uses printf
242 together with this format string to create output similar to the PRINT
243 function, only that the printf function is supplied with the parameters
244 I<filename>, I<xsize> and I<ysize>. In order to generate an B<IMG> tag
245 suitable for including the graph into a web page, the command line
246 would look like this:
248 --imginfo '<IMG SRC="/img/%s" WIDTH="%lu" HEIGHT="%lu" ALT="Demo">'
250 [B<-c>|B<--color> I<COLORTAG>#I<rrggbb>[I<aa>]]
252 Override the default colors for the standard elements of the graph. The
253 I<COLORTAG> is one of C<BACK> background, C<CANVAS> for the background of
254 the actual graph, C<SHADEA> for the left and top border, C<SHADEB> for the
255 right and bottom border, C<GRID>, C<MGRID> for the major grid, C<FONT> for
256 the color of the font, C<AXIS> for the axis of the graph, C<FRAME> for the
257 line around the color spots and finally C<ARROW> for the arrow head pointing
258 up and forward. Each color is composed out of three hexadecimal numbers
259 specifying its rgb color component (00 is off, FF is maximum) of red, green
260 and blue. Optionally you may add another hexadecimal number specifying the
261 transparency (FF is solid). You may set this option several times to alter
262 multiple defaults.
264 A green arrow is made by: C<--color ARROW#00FF00>
266 [B<--zoom> I<factor>]
268 Zoom the graphics by the given amount. The factor must be E<gt> 0
270 [B<-n>|B<--font> I<FONTTAG>B<:>I<size>B<:>[I<font>]]
272 This lets you customize which font to use for the various text
273 elements on the RRD graphs. C<DEFAULT> sets the default value for all
274 elements, C<TITLE> for the title, C<AXIS> for the axis labels, C<UNIT>
275 for the vertical unit label, C<LEGEND> for the graph legend.
277 Use Times for the title: C<--font TITLE:13:/usr/lib/fonts/times.ttf>
279 If you do not give a font string you can modify just the sice of the default font:
280 C<--font TITLE:13:>.
282 If you specify the size 0 then you can modify just the font without touching
283 the size. This is especially usefull for altering the default font without
284 resetting the default fontsizes: C<--font DEFAULT:0:/usr/lib/fonts/times.ttf>.
286 RRDtool comes with a preset default font. You can set the environment
287 variable C<RRD_DEFAULT_FONT> if you want to change this.
289 Truetype fonts are only supported for PNG output. See below.
291 [B<-R>|B<--font-render-mode> {I<normal>,I<light>,I<mono>}]
293 This lets you customize the strength of the font smoothing,
294 or disable it entirely using I<mono>. By default, I<normal>
295 font smoothing is used.
297 [B<-B>|B<--font-smoothing-threshold> I<size>]
299 This specifies the largest font size which will be rendered
300 bitmapped, that is, without any font smoothing. By default,
301 no text is rendered bitmapped.
303 [B<-E>|B<--slope-mode>]
305 RRDtool graphs are composed of stair case curves by default. This is in line with
306 the way RRDtool calculates its data. Some people favor a more 'organic' look
307 for their graphs even though it is not all that true.
309 [B<-a>|B<--imgformat> B<PNG>|B<SVG>|B<EPS>|B<PDF>]
311 Image format for the generated graph. For the vector formats you can
312 choose among the standard Postscript fonts Courier-Bold,
313 Courier-BoldOblique, Courier-Oblique, Courier, Helvetica-Bold,
314 Helvetica-BoldOblique, Helvetica-Oblique, Helvetica, Symbol,
315 Times-Bold, Times-BoldItalic, Times-Italic, Times-Roman, and ZapfDingbats.
317 [B<-i>|B<--interlaced>]
319 If images are interlaced they become visible on browsers more quickly.
321 [B<-g>|B<--no-legend>]
323 Suppress generation of the legend; only render the graph.
325 [B<-F>|B<--force-rules-legend>]
327 Force the generation of HRULE and VRULE legends even if those HRULE or
328 VRULE will not be drawn because out of graph boundaries (mimics
329 behaviour of pre 1.0.42 versions).
331 [B<-T>|B<--tabwidth> I<value>]
333 By default the tab-width is 40 pixels, use this option to change it.
335 [B<-b>|B<--base> I<value>]
337 If you are graphing memory (and NOT network traffic) this switch
338 should be set to 1024 so that one Kb is 1024 byte. For traffic
339 measurement, 1 kb/s is 1000 b/s.
341 [B<-W>|B<--watermark> I<string>]
343 Adds the given string as a watermark, horizontally centred, at the bottom
344 of the graph.
346 =item Data and variables
348 B<DEF:>I<vname>B<=>I<rrdfile>B<:>I<ds-name>B<:>I<CF>[B<:step=>I<step>][B<:start=>I<time>][B<:end=>I<time>]
350 B<CDEF:>I<vname>B<=>I<RPN expression>
352 B<VDEF:>I<vname>B<=>I<RPN expression>
354 You need at least one B<DEF> statement to generate anything. The
355 other statements are useful but optional.
356 See L<rrdgraph_data> and L<rrdgraph_rpn> for the exact format.
358 =item Graph and print elements
360 You need at least one graph element to generate an image and/or
361 at least one print statement to generate a report.
362 See L<rrdgraph_graph> for the exact format.
364 =back
366 =head1 SEE ALSO
368 L<rrdgraph> gives an overview of how B<rrdtool graph> works.
369 L<rrdgraph_data> describes B<DEF>,B<CDEF> and B<VDEF> in detail.
370 L<rrdgraph_rpn> describes the B<RPN> language used in the B<?DEF> statements.
371 L<rrdgraph_graph> page describes all of the graph and print functions.
373 Make sure to read L<rrdgraph_examples> for tipsE<amp>tricks.
375 =head1 AUTHOR
377 Program by Tobias Oetiker E<lt>oetiker@ee.ethz.chE<gt>
379 This manual page by Alex van den Bogaerdt E<lt>alex@ergens.op.het.netE<gt>