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 Read values from SNMP (Simple Network Management Protocol) enabled
139 network devices such as switches, routers, thermometers, rack monitoring
140 servers, etc. See collectd-snmp(5).
143 Pages swapped out onto harddisk or whatever is called `swap' by the OS..
146 Bytes and operations read and written on tape devices. Solaris only.
149 Users currently logged in.
152 System resources used by Linux VServers.
153 See <http://linux-vserver.org/>.
156 Link quality of wireless cards. Linux only.
159 Bitrate and frequency of music played with XMMS.
161 * Output can be written or send to various destinations by the following
165 Write to comma separated values (CSV) files. This needs lots of
166 diskspace but is extremely portable and can be analysed with almost
167 every program that can analyse anything. Even Microsoft's Excel..
170 Send the data to a remote host to save the data somehow. This is useful
171 for large setups where the data should be saved by a dedicated machine.
174 Of course the values are propagated to plugins written in Perl, too, so
175 you can easily do weird stuff with the plugins we didn't dare think of
176 ;) See collectd-perl(5).
179 Output to round-robin-database (RRD) files using librrd. See rrdtool(1).
180 This is likely the most popular destination for such values. Since
181 updates to RRD-files are somewhat expensive this plugin can cache
182 updates to the files and write a bunch of updates at once, which lessens
186 One can query the values from the unixsock plugin whenever they're
187 needed. Please read collectd-unixsock(5) for a description on how that's
190 * Logging is, as everything in collectd, provided by plugins. The following
191 plugins keep up informed about what's going on:
194 Writes logmessages to a file or STDOUT/STDERR.
197 Logs to the standard UNIX logging mechanism, syslog.
199 * Performance: Since collectd is running as a daemon it doesn't spend much
200 time starting up again and again. With the exception of the exec plugin no
201 processes are forked. Caching in output plugins, such as the rrdtool and
202 network plugins, makes sure your resources are used efficiently. Also,
203 since collectd is programmed multithreaded it benefits from hyperthreading
204 and multicore processors and makes sure that the daemon isn't idle if only
205 one plugins waits for an IO-operation to complete.
207 * Once set up, hardly any maintenance is necessary. Setup is kept as easy
208 as possible and the default values should be okay for most users.
214 * collectd's configuration file can be found at `sysconfdir'/collectd.conf.
215 Run `collectd -h' for a list of builtin defaults. See `collectd.conf(5)'
216 for a list of options and a syntax description.
218 * When the `csv' or `rrdtool' plugins are loaded they'll write the values to
219 files. The usual place for these files is beneath `/var/lib/collectd'.
221 * When using some of the plugins, collectd needs to run as user root, since only
222 root can do certain things, such as craft ICMP packages needed to ping
223 other hosts. collectd should NOT be installed setuid root since it can be
224 used to overwrite valuable files!
226 * Sample scripts to generate graphs reside in `contrib/' in the source
227 package or somewhere near `/usr/share/doc/collectd' in most distributions.
228 Please be aware that those script are meant as a starting point for your
229 own experiments.. Some of them require the `RRDs' Perl module.
230 (`librrds-perl' on Debian) If you have written a more sophisticated
231 solution please share it with us.
233 * The RRAs of the automatically created RRD files depend on the `step'
234 and `heartbeat' settings given. If change these settings you may need to
235 re-create the files, losing all data. Please be aware of that when changing
236 the values and read the rrdtool(1) manpage thoroughly.
242 To compile collectd from source you will need:
244 * Usual suspects: C compiler, linker, preprocessor, make, ...
246 * A POSIX-threads (pthread) implementation.
247 Since gathering some statistics is slow (network connections, slow devices,
248 etc) the collectd is parallelized. The POSIX threads interface is being
249 used and should be found in various implementations for hopefully all
253 If you want to use the `apache' plugin
256 For querying iptables counters.
258 * libmysqlclient (optional)
260 * libnetlink (optional)
262 * libnetsnmp (optional)
264 * liboping (optional, if not found a version shipped with this distribution
266 Used by the `ping' plugin to send and receive ICMP packets.
269 Used to capture packets by the `dns' plugin.
271 * librrd (optional; headers and library; rrdtool 1.0 and 1.2 both work fine)
272 If built without `librrd' the resulting binary will be `client only', i.e.
273 will send its values via multicast and not create any RRD files itself.
274 Alternatively you can chose to write CSV-files (Comma Separated Values)
277 * libsensors (optional)
278 To read from `lm_sensors'.
280 * libstatgrab may be used to collect statistics on systems other than Linux
281 and/or Solaris. Note that CPU- and disk-statistics, while being provided
282 by this library, are not supported in collectd right now..
283 <http://www.i-scream.org/libstatgrab/>
285 * libupsclient/nut (optional)
286 For the `nut' plugin which queries nut's `upsd'.
290 * librt, libsocket, libkstat, libdevinfo
291 Various standard Solaris libraries which provide system functions.
293 * CoreFoundation.framework and IOKit.framework
294 For compiling on Darwin in general and the `apple_sensors' plugin in
301 To compile correctly collectd needs to be able to initialize static
302 variables to NAN (Not A Number). Some C libraries, especially the GNU
303 libc, have a problem with that.
305 Luckily, with GCC it's possible to work around that problem: One can define
306 NAN as being (0.0 / 0.0) and `isnan' as `f != f'. However, to test this
307 ``implementation'' the configure script needs to compile and run a short
308 test program. Obviously running a test program when doing a cross-
309 compilation is, well, challenging.
311 If you run into this problem, you can use the `--with-nan-emulation'
312 configure option to force the use of this implementation. We can't promise
313 that the compiled binary actually behaves as it should, but since NANs
314 are likely never passed to the libm you have a good chance to be lucky.
320 For questions, bugreports, development information and basically all other
321 concerns please send an email to collectd's mailinglist at
322 <collectd at verplant.org>.
324 For live discussion and more personal contact visit us in IRC, we're in
325 channel #collectd on freenode.
331 Florian octo Forster <octo at verplant.org>,
332 Sebastian tokkee Harl <sh at tokkee.org>,
333 and many contributors (see `AUTHORS').
335 Please send bugreports and patches to the mailinglist, see `Contact' above.