1 collectd - System information collection daemon
2 =================================================
8 collectd is a small daemon which collects statistics about a computer's
9 usage and writes then into RRD files.
15 * collectd is able to collect the following data:
18 Apache server utilization: Number of bytes transfered, number of
19 requests handled and detailed scoreboard statistics
22 APC UPS Daemon: UPS charge, load, input/output/battery voltage, etc.
25 Sensors in Macs running Mac OS X / Darwin: Temperature, fanspeed and
29 Batterycharge, -current and voltage of ACPI and PMU based laptop
33 CPU utilization: Time spent in the system, user, nice, idle, and related
37 CPU frequency (For laptops with speed step or a similar technology)
40 Mountpoint usage (Basically the values `df(1)' delivers)
43 Disk utilization: Sectors read/written, number of read/write actions,
44 average time an IO-operation took to complete.
47 DNS traffic: Query types, response codes, opcodes and traffic/octets
51 Email statistics: Count, traffic, spam scores and checks.
52 See collectd-email(5).
55 Amount of entropy available to the system.
58 Values gathered by a custom program or script.
62 Harddisk temperatures using hddtempd.
65 Interface traffic: Number of octets, packets and errors for each
69 Iptables' counters: Number of bytes that were matched by a certain
73 IRQ counters: Frequency in which certain interrupts occur.
76 System load average over the last 1, 5 and 15 minutes.
79 Motherboard sensors: temperature, fanspeed and voltage information,
83 Memory utilization: Memory occupied by running processes, page cache,
84 buffer cache and free.
87 Information provided by serial multimeters, such as the `Metex
91 MySQL server statistics: Commands issued, handlers triggered, thread
92 usage, query cache utilization and traffic/octets sent and received.
95 Very detailed Linux network interface and routing statistics. You can get
96 (detailed) information on interfaces, qdiscs, classes, and, if you can
97 make use of it, filters.
100 Receive values that were collected by other hosts. Large setups will
101 want to collect the data on one dedicated machine, and this is the
102 plugin of choice for that.
105 NFS Procedures: Which NFS command were called how often. Only NFSv2 and
109 NTP daemon statistics: Local clock drift, offset to peers, etc.
112 Network UPS tools: UPS current, voltage, power, charge, utilisation,
113 temperature, etc. See upsd(8).
116 The perl plugin implements a Perl-interpreter into collectd. You can
117 write your own plugins in Perl and return arbitrary values using this
118 API. See collectd-perl(5).
120 This plugin is still considered to be experimental and subject to change
121 between minor releases.
124 Network latency: Time to reach the default gateway or another given
128 Process counts: Number of running, sleeping, zombie, ... processes.
131 System sensors, accessed using lm_sensors: Voltages, temperatures and
135 RX and TX of serial interfaces. Linux only; needs root privileges.
138 Pages swapped out onto harddisk or whatever is called `swap' by the OS..
141 Bytes and operations read and written on tape devices. Solaris only.
144 Users currently logged in.
147 System resources used by Linux VServers.
148 See <http://linux-vserver.org/>.
151 Link quality of wireless cards. Linux only.
153 * Output can be written or send to various destinations by the following
157 Write to comma separated values (CSV) files. This needs lots of
158 diskspace but is extremely portable and can be analysed with almost
159 every program that can analyse anything. Even Microsoft's Excel..
162 Send the data to a remote host to save the data somehow. This is useful
163 for large setups where the data should be saved by a dedicated machine.
166 Of course the values are propagated to plugins written in Perl, too, so
167 you can easily do weird stuff with the plugins we didn't dare think of
168 ;) See collectd-perl(5).
171 Output to round-robin-database (RRD) files using librrd. See rrdtool(1).
172 This is likely the most popular destination for such values. Since
173 updates to RRD-files are somewhat expensive this plugin can cache
174 updates to the files and write a bunch of updates at once, which lessens
178 One can query the values from the unixsock plugin whenever they're
179 needed. Please read collectd-unixsock(5) for a description on how that's
182 * Logging is, as everything in collectd, provided by plugins. The following
183 plugins keep up informed about what's going on:
186 Writes logmessages to a file or STDOUT/STDERR.
189 Logs to the standard UNIX logging mechanism, syslog.
191 * Performance: Since collectd is running as a daemon it doesn't spend much
192 time starting up again and again. With the exception of the exec plugin no
193 processes are forked. Caching in output plugins, such as the rrdtool and
194 network plugins, makes sure your resources are used efficiently. Also,
195 since collectd is programmed multithreaded it benefits from hyperthreading
196 and multicore processors and makes sure that the daemon isn't idle if only
197 one plugins waits for an IO-operation to complete.
199 * Once set up, hardly any maintenance is necessary. Setup is kept as easy
200 as possible and the default values should be okay for most users.
206 * collectd's configuration file can be found at `sysconfdir'/collectd.conf.
207 Run `collectd -h' for a list of builtin defaults. See `collectd.conf(5)'
208 for a list of options and a syntax description.
210 * When the `csv' or `rrdtool' plugins are loaded they'll write the values to
211 files. The usual place for these files is beneath `/var/lib/collectd'.
213 * When using some of the plugins, collectd needs to run as user root, since only
214 root can do certain things, such as craft ICMP packages needed to ping
215 other hosts. collectd should NOT be installed setuid root since it can be
216 used to overwrite valuable files!
218 * Sample scripts to generate graphs reside in `contrib/' in the source
219 package or somewhere near `/usr/share/doc/collectd' in most distributions.
220 Please be aware that those script are meant as a starting point for your
221 own experiments.. Some of them require the `RRDs' Perl module.
222 (`librrds-perl' on Debian) If you have written a more sophisticated
223 solution please share it with us.
225 * The RRAs of the automatically created RRD files depend on the `step'
226 and `heartbeat' settings given. If change these settings you may need to
227 re-create the files, losing all data. Please be aware of that when changing
228 the values and read the rrdtool(1) manpage thoroughly.
234 To compile collectd from source you will need:
236 * Usual suspects: C compiler, linker, preprocessor, make, ...
238 * A POSIX-threads (pthread) implementation.
239 Since gathering some statistics is slow (network connections, slow devices,
240 etc) the collectd is parallelized. The POSIX threads interface is being
241 used and should be found in various implementations for hopefully all
245 If you want to use the `apache' plugin
248 For querying iptables counters.
250 * libmysqlclient (optional)
252 * liboping (optional, if not found a version shipped with this distribution
254 Used by the `ping' plugin to send and receive ICMP packets.
257 Used to capture packets by the `dns' plugin.
259 * librrd (optional; headers and library; rrdtool 1.0 and 1.2 both work fine)
260 If built without `librrd' the resulting binary will be `client only', i.e.
261 will send its values via multicast and not create any RRD files itself.
262 Alternatively you can chose to write CSV-files (Comma Separated Values)
265 * libsensors (optional)
266 To read from `lm_sensors'.
268 * libstatgrab may be used to collect statistics on systems other than Linux
269 and/or Solaris. Note that CPU- and disk-statistics, while being provided
270 by this library, are not supported in collectd right now..
271 <http://www.i-scream.org/libstatgrab/>
273 * libupsclient/nut (optional)
274 For the `nut' plugin which queries nut's `upsd'.
276 * librt, libsocket, libkstat, libdevinfo
277 Various standard Solaris libraries which provide system functions.
279 * CoreFoundation.framework and IOKit.framework
280 For compiling on Darwin in general and the `apple_sensors' plugin in
287 To compile correctly collectd needs to be able to initialize static
288 variables to NAN (Not A Number). Some C libraries, especially the GNU
289 libc, have a problem with that.
291 Luckily, with GCC it's possible to work around that problem: One can define
292 NAN as being (0.0 / 0.0) and `isnan' as `f != f'. However, to test this
293 ``implementation'' the configure script needs to compile and run a short
294 test program. Obviously running a test program when doing a cross-
295 compilation is, well, challenging.
297 If you run into this problem, you can use the `--with-nan-emulation'
298 configure option to force the use of this implementation. We can't promise
299 that the compiled binary actually behaves as it should, but since NANs
300 are likely never passed to the libm you have a good chance to be lucky.
306 For questions, bugreports, development information and basically all other
307 concerns please send an email to collectd's mailinglist at
308 <collectd at verplant.org>.
310 For live discussion and more personal contact visit us in IRC, we're in
311 channel #collectd on freenode.
317 Florian octo Forster <octo at verplant.org>,
318 Sebastian tokkee Harl <sh at tokkee.org>,
319 and many contributors (see `AUTHORS').
321 Please send bugreports and patches to the mailinglist, see `Contact' above.