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 IPVS connection statistics (number of connections, octets and packets
74 for each service and destination).
75 See http://www.linuxvirtualserver.org/software/index.html.
78 IRQ counters: Frequency in which certain interrupts occur.
81 System load average over the last 1, 5 and 15 minutes.
84 Motherboard sensors: temperature, fanspeed and voltage information,
88 Memory utilization: Memory occupied by running processes, page cache,
89 buffer cache and free.
92 Information provided by serial multimeters, such as the `Metex
96 MySQL server statistics: Commands issued, handlers triggered, thread
97 usage, query cache utilization and traffic/octets sent and received.
100 Very detailed Linux network interface and routing statistics. You can get
101 (detailed) information on interfaces, qdiscs, classes, and, if you can
102 make use of it, filters.
105 Receive values that were collected by other hosts. Large setups will
106 want to collect the data on one dedicated machine, and this is the
107 plugin of choice for that.
110 NFS Procedures: Which NFS command were called how often. Only NFSv2 and
114 Collects statistics from `nginx' (speak: engine X), a HTTP and mail
118 NTP daemon statistics: Local clock drift, offset to peers, etc.
121 Network UPS tools: UPS current, voltage, power, charge, utilisation,
122 temperature, etc. See upsd(8).
125 The perl plugin implements a Perl-interpreter into collectd. You can
126 write your own plugins in Perl and return arbitrary values using this
127 API. See collectd-perl(5).
129 This plugin is still considered to be experimental and subject to change
130 between minor releases.
133 Network latency: Time to reach the default gateway or another given
137 Process counts: Number of running, sleeping, zombie, ... processes.
140 System sensors, accessed using lm_sensors: Voltages, temperatures and
144 RX and TX of serial interfaces. Linux only; needs root privileges.
147 Read values from SNMP (Simple Network Management Protocol) enabled
148 network devices such as switches, routers, thermometers, rack monitoring
149 servers, etc. See collectd-snmp(5).
152 Pages swapped out onto harddisk or whatever is called `swap' by the OS..
155 Bytes and operations read and written on tape devices. Solaris only.
158 Number of TCP connections to specific local and remote ports.
161 Users currently logged in.
164 System resources used by Linux VServers.
165 See <http://linux-vserver.org/>.
168 Link quality of wireless cards. Linux only.
171 Bitrate and frequency of music played with XMMS.
173 * Output can be written or send to various destinations by the following
177 Write to comma separated values (CSV) files. This needs lots of
178 diskspace but is extremely portable and can be analysed with almost
179 every program that can analyse anything. Even Microsoft's Excel..
182 Send the data to a remote host to save the data somehow. This is useful
183 for large setups where the data should be saved by a dedicated machine.
186 Of course the values are propagated to plugins written in Perl, too, so
187 you can easily do weird stuff with the plugins we didn't dare think of
188 ;) See collectd-perl(5).
191 Output to round-robin-database (RRD) files using librrd. See rrdtool(1).
192 This is likely the most popular destination for such values. Since
193 updates to RRD-files are somewhat expensive this plugin can cache
194 updates to the files and write a bunch of updates at once, which lessens
198 One can query the values from the unixsock plugin whenever they're
199 needed. Please read collectd-unixsock(5) for a description on how that's
202 * Logging is, as everything in collectd, provided by plugins. The following
203 plugins keep up informed about what's going on:
206 Writes logmessages to a file or STDOUT/STDERR.
209 Logs to the standard UNIX logging mechanism, syslog.
211 * Performance: Since collectd is running as a daemon it doesn't spend much
212 time starting up again and again. With the exception of the exec plugin no
213 processes are forked. Caching in output plugins, such as the rrdtool and
214 network plugins, makes sure your resources are used efficiently. Also,
215 since collectd is programmed multithreaded it benefits from hyperthreading
216 and multicore processors and makes sure that the daemon isn't idle if only
217 one plugins waits for an IO-operation to complete.
219 * Once set up, hardly any maintenance is necessary. Setup is kept as easy
220 as possible and the default values should be okay for most users.
226 * collectd's configuration file can be found at `sysconfdir'/collectd.conf.
227 Run `collectd -h' for a list of builtin defaults. See `collectd.conf(5)'
228 for a list of options and a syntax description.
230 * When the `csv' or `rrdtool' plugins are loaded they'll write the values to
231 files. The usual place for these files is beneath `/var/lib/collectd'.
233 * When using some of the plugins, collectd needs to run as user root, since
234 only root can do certain things, such as craft ICMP packages needed to ping
235 other hosts. collectd should NOT be installed setuid root since it can be
236 used to overwrite valuable files!
238 * Sample scripts to generate graphs reside in `contrib/' in the source
239 package or somewhere near `/usr/share/doc/collectd' in most distributions.
240 Please be aware that those script are meant as a starting point for your
241 own experiments.. Some of them require the `RRDs' Perl module.
242 (`librrds-perl' on Debian) If you have written a more sophisticated
243 solution please share it with us.
245 * The RRAs of the automatically created RRD files depend on the `step'
246 and `heartbeat' settings given. If change these settings you may need to
247 re-create the files, losing all data. Please be aware of that when changing
248 the values and read the rrdtool(1) manpage thoroughly.
251 collectd and chkrootkit
252 -----------------------
254 If you are using the `dns' plugin chkrootkit(1) will report collectd as a
255 packet sniffer ("<iface>: PACKET SNIFFER(/usr/sbin/collectd[<pid>])"). The
256 plugin captures all UDP packets on port 53 to analyze the DNS traffic. In
257 this case, collectd is a legitimate sniffer and the report should be
258 considered to be a false positive. However, you might want to check that
259 this really is collectd and not some other, illegitimate sniffer.
265 To compile collectd from source you will need:
267 * Usual suspects: C compiler, linker, preprocessor, make, ...
269 * A POSIX-threads (pthread) implementation.
270 Since gathering some statistics is slow (network connections, slow devices,
271 etc) the collectd is parallelized. The POSIX threads interface is being
272 used and should be found in various implementations for hopefully all
276 If you want to use the `apache' plugin
279 For querying iptables counters.
281 * libmysqlclient (optional)
283 * libnetlink (optional)
285 * libnetsnmp (optional)
287 * liboping (optional, if not found a version shipped with this distribution
289 Used by the `ping' plugin to send and receive ICMP packets.
292 Used to capture packets by the `dns' plugin.
294 * librrd (optional; headers and library; rrdtool 1.0 and 1.2 both work fine)
295 If built without `librrd' the resulting binary will be `client only', i.e.
296 will send its values via multicast and not create any RRD files itself.
297 Alternatively you can chose to write CSV-files (Comma Separated Values)
300 * libsensors (optional)
301 To read from `lm_sensors'.
303 * libstatgrab may be used to collect statistics on systems other than Linux
304 and/or Solaris. Note that CPU- and disk-statistics, while being provided
305 by this library, are not supported in collectd right now..
306 <http://www.i-scream.org/libstatgrab/>
308 * libupsclient/nut (optional)
309 For the `nut' plugin which queries nut's `upsd'.
313 * librt, libsocket, libkstat, libdevinfo
314 Various standard Solaris libraries which provide system functions.
316 * CoreFoundation.framework and IOKit.framework
317 For compiling on Darwin in general and the `apple_sensors' plugin in
324 To compile correctly collectd needs to be able to initialize static
325 variables to NAN (Not A Number). Some C libraries, especially the GNU
326 libc, have a problem with that.
328 Luckily, with GCC it's possible to work around that problem: One can define
329 NAN as being (0.0 / 0.0) and `isnan' as `f != f'. However, to test this
330 ``implementation'' the configure script needs to compile and run a short
331 test program. Obviously running a test program when doing a cross-
332 compilation is, well, challenging.
334 If you run into this problem, you can use the `--with-nan-emulation'
335 configure option to force the use of this implementation. We can't promise
336 that the compiled binary actually behaves as it should, but since NANs
337 are likely never passed to the libm you have a good chance to be lucky.
343 For questions, bugreports, development information and basically all other
344 concerns please send an email to collectd's mailinglist at
345 <collectd at verplant.org>.
347 For live discussion and more personal contact visit us in IRC, we're in
348 channel #collectd on freenode.
354 Florian octo Forster <octo at verplant.org>,
355 Sebastian tokkee Harl <sh at tokkee.org>,
356 and many contributors (see `AUTHORS').
358 Please send bugreports and patches to the mailinglist, see `Contact' above.