1 collectd - System information collection daemon
2 =================================================
3 http://collectd.org/
5 About
6 -----
8 collectd is a small daemon which collects statistics about a computer's
9 usage and writes then into RRD files.
12 Features
13 --------
15 * collectd is able to collect the following data:
17 - apache
18 Apache server utilization: Number of bytes transfered, number of
19 requests handled and detailed scoreboard statistics
21 - apcups
22 APC UPS Daemon: UPS charge, load, input/output/battery voltage, etc.
24 - apple_sensors
25 Sensors in Macs running Mac OS X / Darwin: Temperature, fanspeed and
26 voltage sensors.
28 - battery
29 Batterycharge, -current and voltage of ACPI and PMU based laptop
30 batteries.
32 - cpu
33 CPU utilization: Time spent in the system, user, nice, idle, and related
34 states.
36 - cpufreq
37 CPU frequency (For laptops with speed step or a similar technology)
39 - df
40 Mountpoint usage (Basically the values `df(1)' delivers)
42 - disk
43 Disk utilization: Sectors read/written, number of read/write actions,
44 average time an IO-operation took to complete.
46 - dns
47 DNS traffic: Query types, response codes, opcodes and traffic/octets
48 transfered.
50 - email
51 Email statistics: Count, traffic, spam scores and checks.
52 See collectd-email(5).
54 - entropy
55 Amount of entropy available to the system.
57 - exec
58 Values gathered by a custom program or script.
59 See collectd-exec(5).
61 - hddtemp
62 Harddisk temperatures using hddtempd.
64 - interface
65 Interface traffic: Number of octets, packets and errors for each
66 interface.
68 - iptables
69 Iptables' counters: Number of bytes that were matched by a certain
70 iptables rule.
72 - irq
73 IRQ counters: Frequency in which certain interrupts occur.
75 - load
76 System load average over the last 1, 5 and 15 minutes.
78 - mbmon
79 Motherboard sensors: temperature, fanspeed and voltage information,
80 using mbmon(1).
82 - memory
83 Memory utilization: Memory occupied by running processes, page cache,
84 buffer cache and free.
86 - multimeter
87 Information provided by serial multimeters, such as the `Metex
88 M-4650CR'.
90 - mysql
91 MySQL server statistics: Commands issued, handlers triggered, thread
92 usage, query cache utilization and traffic/octets sent and received.
94 - network
95 Receive values that were collected by other hosts. Large setups will
96 want to collect the data on one dedicated machine, and this is the
97 plugin of choice for that.
99 - nfs
100 NFS Procedures: Which NFS command were called how often. Only NFSv2 and
101 NFSv3 right now.
103 - ntp
104 NTP daemon statistics: Local clock drift, offset to peers, etc.
106 - nut
107 Network UPS tools: UPS current, voltage, power, charge, utilisation,
108 temperature, etc. See upsd(8).
110 - perl
111 The perl plugin implements a Perl-interpreter into collectd. You can
112 write your own plugins in Perl and return arbitrary values using this
113 API. See collectd-perl(5).
115 This plugin is still considered to be experimental and subject to change
116 between minor releases.
118 - ping
119 Network latency: Time to reach the default gateway or another given
120 host.
122 - processes
123 Process counts: Number of running, sleeping, zombie, ... processes.
125 - sensors
126 System sensors, accessed using lm_sensors: Voltages, temperatures and
127 fan rotation speeds.
129 - serial
130 RX and TX of serial interfaces. Linux only; needs root privileges.
132 - swap
133 Pages swapped out onto harddisk or whatever is called `swap' by the OS..
135 - tape
136 Bytes and operations read and written on tape devices. Solaris only.
138 - users
139 Users currently logged in.
141 - vserver
142 System resources used by Linux VServers.
143 See <http://linux-vserver.org/>.
145 - wireless
146 Link quality of wireless cards. Linux only.
148 * Output can be written or send to various destinations by the following
149 plugins:
151 - csv
152 Write to comma separated values (CSV) files. This needs lots of
153 diskspace but is extremely portable and can be analysed with almost
154 every program that can analyse anything. Even Microsoft's Excel..
156 - network
157 Send the data to a remote host to save the data somehow. This is useful
158 for large setups where the data should be saved by a dedicated machine.
160 - perl
161 Of course the values are propagated to plugins written in Perl, too, so
162 you can easily do weird stuff with the plugins we didn't dare think of
163 ;) See collectd-perl(5).
165 - rrdtool
166 Output to round-robin-database (RRD) files using librrd. See rrdtool(1).
167 This is likely the most popular destination for such values. Since
168 updates to RRD-files are somewhat expensive this plugin can cache
169 updates to the files and write a bunch of updates at once, which lessens
170 system load a lot.
172 - unixsock
173 One can query the values from the unixsock plugin whenever they're
174 needed. Please read collectd-unixsock(5) for a description on how that's
175 done.
177 * Logging is, as everything in collectd, provided by plugins. The following
178 plugins keep up informed about what's going on:
180 - logfile
181 Writes logmessages to a file or STDOUT/STDERR.
183 - syslog
184 Logs to the standard UNIX logging mechanism, syslog.
186 * Performance: Since collectd is running as a daemon it doesn't spend much
187 time starting up again and again. With the exception of the exec plugin no
188 processes are forked. Caching in output plugins, such as the rrdtool and
189 network plugins, makes sure your resources are used efficiently. Also,
190 since collectd is programmed multithreaded it benefits from hyperthreading
191 and multicore processors and makes sure that the daemon isn't idle if only
192 one plugins waits for an IO-operation to complete.
194 * Once set up, hardly any maintenance is necessary. Setup is kept as easy
195 as possible and the default values should be okay for most users.
198 Operation
199 ---------
201 * collectd's configuration file can be found at `sysconfdir'/collectd.conf.
202 Run `collectd -h' for a list of builtin defaults. See `collectd.conf(5)'
203 for a list of options and a syntax description.
205 * When the `csv' or `rrdtool' plugins are loaded they'll write the values to
206 files. The usual place for these files is beneath `/var/lib/collectd'.
208 * When using some of the plugins, collectd needs to run as user root, since only
209 root can do certain things, such as craft ICMP packages needed to ping
210 other hosts. collectd should NOT be installed setuid root since it can be
211 used to overwrite valuable files!
213 * Sample scripts to generate graphs reside in `contrib/' in the source
214 package or somewhere near `/usr/share/doc/collectd' in most distributions.
215 Please be aware that those script are meant as a starting point for your
216 own experiments.. Some of them require the `RRDs' Perl module.
217 (`librrds-perl' on Debian) If you have written a more sophisticated
218 solution please share it with us.
220 * The RRAs of the automatically created RRD files depend on the `step'
221 and `heartbeat' settings given. If change these settings you may need to
222 re-create the files, losing all data. Please be aware of that when changing
223 the values and read the rrdtool(1) manpage thoroughly.
226 Prerequisites
227 -------------
229 To compile collectd from source you will need:
231 * Usual suspects: C compiler, linker, preprocessor, make, ...
233 * A POSIX-threads (pthread) implementation.
234 Since gathering some statistics is slow (network connections, slow devices,
235 etc) the collectd is parallelized. The POSIX threads interface is being
236 used and should be found in various implementations for hopefully all
237 platforms.
239 * libcurl (optional)
240 If you want to use the `apache' plugin
242 * libiptc (optional)
243 For querying iptables counters.
245 * libmysqlclient (optional)
247 * liboping (optional, if not found a version shipped with this distribution
248 can be used)
249 Used by the `ping' plugin to send and receive ICMP packets.
251 * libpcap (optional)
252 Used to capture packets by the `dns' plugin.
254 * librrd (optional; headers and library; rrdtool 1.0 and 1.2 both work fine)
255 If built without `librrd' the resulting binary will be `client only', i.e.
256 will send its values via multicast and not create any RRD files itself.
257 Alternatively you can chose to write CSV-files (Comma Separated Values)
258 instead.
260 * libsensors (optional)
261 To read from `lm_sensors'.
263 * libstatgrab may be used to collect statistics on systems other than Linux
264 and/or Solaris. Note that CPU- and disk-statistics, while being provided
265 by this library, are not supported in collectd right now..
266 <http://www.i-scream.org/libstatgrab/>
268 * libupsclient/nut (optional)
269 For the `nut' plugin which queries nut's `upsd'.
271 * librt, libsocket, libkstat, libdevinfo
272 Various standard Solaris libraries which provide system functions.
274 * CoreFoundation.framework and IOKit.framework
275 For compiling on Darwin in general and the `apple_sensors' plugin in
276 particular.
279 Crosscompiling
280 --------------
282 To compile correctly collectd needs to be able to initialize static
283 variables to NAN (Not A Number). Some C libraries, especially the GNU
284 libc, have a problem with that.
286 Luckily, with GCC it's possible to work around that problem: One can define
287 NAN as being (0.0 / 0.0) and `isnan' as `f != f'. However, to test this
288 ``implementation'' the configure script needs to compile and run a short
289 test program. Obviously running a test program when doing a cross-
290 compilation is, well, challenging.
292 If you run into this problem, you can use the `--with-nan-emulation'
293 configure option to force the use of this implementation. We can't promise
294 that the compiled binary actually behaves as it should, but since NANs
295 are likely never passed to the libm you have a good chance to be lucky.
298 Contact
299 -------
301 For questions, bugreports, development information and basically all other
302 concerns please send an email to collectd's mailinglist at
303 <collectd at verplant.org>.
305 For live discussion and more personal contact visit us in IRC, we're in
306 channel #collectd on freenode.
309 Author
310 ------
312 Florian octo Forster <octo at verplant.org>,
313 Sebastian tokkee Harl <sh at tokkee.org>,
314 and many contributors (see `AUTHORS').
316 Please send bugreports and patches to the mailinglist, see `Contact' above.