README

 collectd - System information collection daemon
=================================================
http://collectd.org/

About
-----

  collectd is a small daemon which collects system information periodically
  and provides mechanisms to store and monitor the values in a variety of
  ways.


Features
--------

  * collectd is able to collect the following data:

    - apache
      Apache server utilization: Number of bytes transfered, number of
      requests handled and detailed scoreboard statistics

    - apcups
      APC UPS Daemon: UPS charge, load, input/output/battery voltage, etc.

    - apple_sensors
      Sensors in Macs running Mac OS X / Darwin: Temperature, fanspeed and
      voltage sensors.

    - ascent
      Statistics about Ascent, a free server for the game `World of Warcraft'.

    - battery
      Batterycharge, -current and voltage of ACPI and PMU based laptop
      batteries.

    - cpu
      CPU utilization: Time spent in the system, user, nice, idle, and related
      states.

    - cpufreq
      CPU frequency (For laptops with speed step or a similar technology)

    - dbi
      Executes SQL statements on various databases and interprets the returned
      data.

    - df
      Mountpoint usage (Basically the values `df(1)' delivers)

    - disk
      Disk utilization: Sectors read/written, number of read/write actions,
      average time an IO-operation took to complete.

    - dns
      DNS traffic: Query types, response codes, opcodes and traffic/octets
      transfered.

    - email
      Email statistics: Count, traffic, spam scores and checks.
      See collectd-email(5).

    - entropy
      Amount of entropy available to the system.

    - exec
      Values gathered by a custom program or script.
      See collectd-exec(5).

    - filecount
      Count the number of files in directories.

    - hddtemp
      Harddisk temperatures using hddtempd.

    - interface
      Interface traffic: Number of octets, packets and errors for each
      interface.

    - iptables
      Iptables' counters: Number of bytes that were matched by a certain
      iptables rule.

    - ipmi
      IPMI (Intelligent Platform Management Interface) sensors information.

    - ipvs
      IPVS connection statistics (number of connections, octets and packets
      for each service and destination).
      See http://www.linuxvirtualserver.org/software/index.html.

    - irq
      IRQ counters: Frequency in which certain interrupts occur.

    - load
      System load average over the last 1, 5 and 15 minutes.

    - libvirt
      CPU, disk and network I/O statistics from virtual machines.

    - mbmon
      Motherboard sensors: temperature, fanspeed and voltage information,
      using mbmon(1).

    - memcached
      Statistics of the memcached distributed caching system.
      <http://www.danga.com/memcached/>

    - memory
      Memory utilization: Memory occupied by running processes, page cache,
      buffer cache and free.

    - multimeter
      Information provided by serial multimeters, such as the `Metex
      M-4650CR'.

    - mysql
      MySQL server statistics: Commands issued, handlers triggered, thread
      usage, query cache utilization and traffic/octets sent and received.

    - netlink
      Very detailed Linux network interface and routing statistics. You can get
      (detailed) information on interfaces, qdiscs, classes, and, if you can
      make use of it, filters.

    - network
      Receive values that were collected by other hosts. Large setups will
      want to collect the data on one dedicated machine, and this is the
      plugin of choice for that.

    - nfs
      NFS Procedures: Which NFS command were called how often. Only NFSv2 and
      NFSv3 right now.

    - nginx
      Collects statistics from `nginx' (speak: engine X), a HTTP and mail
      server/proxy.

    - ntpd
      NTP daemon statistics: Local clock drift, offset to peers, etc.

    - nut
      Network UPS tools: UPS current, voltage, power, charge, utilisation,
      temperature, etc. See upsd(8).

    - onewire (EXPERIMENTAL!)
      Read onewire sensors using the owcapu library of the owfs project.
      Please read in collectd.conf(5) why this plugin is experimental.

    - openvpn
      RX and TX of each client in openvpn-status.log (status-version 2).
      <http://openvpn.net/index.php/documentation/howto.html>

    - perl
      The perl plugin implements a Perl-interpreter into collectd. You can
      write your own plugins in Perl and return arbitrary values using this
      API. See collectd-perl(5).

    - ping
      Network latency: Time to reach the default gateway or another given
      host.

    - postgresql
      PostgreSQL database statistics: active server connections, transaction
      numbers, block IO, table row manipulations.

    - powerdns
      PowerDNS name server statistics.

    - processes
      Process counts: Number of running, sleeping, zombie, ... processes.

    - rrdcached
      RRDtool caching daemon (RRDcacheD) statistics.

    - sensors
      System sensors, accessed using lm_sensors: Voltages, temperatures and
      fan rotation speeds.

    - serial
      RX and TX of serial interfaces. Linux only; needs root privileges.

    - snmp
      Read values from SNMP (Simple Network Management Protocol) enabled
      network devices such as switches, routers, thermometers, rack monitoring
      servers, etc. See collectd-snmp(5).

    - swap
      Pages swapped out onto harddisk or whatever is called `swap' by the OS..

    - tail
      Follows (tails) logfiles, parses them by lines and submits matched
      values.

    - tape
      Bytes and operations read and written on tape devices. Solaris only.

    - tcpconns
      Number of TCP connections to specific local and remote ports.

    - teamspeak2
      TeamSpeak2 server statistics.

    - thermal
      Linux ACPI thermal zone information.

    - users
      Users currently logged in.

    - vmem
      Virtual memory statistics, e. g. the number of page-ins/-outs or the
      number of pagefaults.

    - vserver
      System resources used by Linux VServers.
      See <http://linux-vserver.org/>.

    - wireless
      Link quality of wireless cards. Linux only.

    - xmms
      Bitrate and frequency of music played with XMMS.

  * Output can be written or send to various destinations by the following
    plugins:

    - csv
      Write to comma separated values (CSV) files. This needs lots of
      diskspace but is extremely portable and can be analysed with almost
      every program that can analyse anything. Even Microsoft's Excel..

    - network
      Send the data to a remote host to save the data somehow. This is useful
      for large setups where the data should be saved by a dedicated machine.

    - perl
      Of course the values are propagated to plugins written in Perl, too, so
      you can easily do weird stuff with the plugins we didn't dare think of
      ;) See collectd-perl(5).

    - rrdcached
      Output to round-robin-database (RRD) files using the RRDtool caching
      daemon (RRDcacheD) - see rrdcached(1). That daemon provides a general
      implementation of the caching done by the `rrdtool' plugin.

    - rrdtool
      Output to round-robin-database (RRD) files using librrd. See rrdtool(1).
      This is likely the most popular destination for such values. Since
      updates to RRD-files are somewhat expensive this plugin can cache
      updates to the files and write a bunch of updates at once, which lessens
      system load a lot.

    - unixsock
      One can query the values from the unixsock plugin whenever they're
      needed. Please read collectd-unixsock(5) for a description on how that's
      done.

  * Filtering and rewriting values dispatched to collectd can be done by the
    following plugins:

    - filter_pcre
      Filter and rewrite value lists based on Perl-compatible regular
      expressions.

  * Logging is, as everything in collectd, provided by plugins. The following
    plugins keep up informed about what's going on:

    - logfile
      Writes logmessages to a file or STDOUT/STDERR.

    - perl
      Log messages are propagated to plugins written in Perl as well.
      See collectd-perl(5).

    - syslog
      Logs to the standard UNIX logging mechanism, syslog.

  * Notifications can be handled by the following plugins:

    - notify_desktop
      Send a desktop notification to a notification daemon, as defined in
      the Desktop Notification Specification. To actually display the
      notifications, notification-daemon is required.
      See http://www.galago-project.org/specs/notification/.

    - notify_email
      Send an E-mail with the notification message to the configured
      recipients.

    - exec
      Execute a program or script to handle the notification.
      See collectd-exec(5).

    - logfile
      Writes the notification message to a file or STDOUT/STDERR.

    - network
      Send the notification to a remote host to handle it somehow.

    - perl
      Notifications are propagated to plugins written in Perl as well.
      See collectd-perl(5).

  * Miscellaneous plugins:

    - uuid
      Sets the hostname to an unique identifier. This is meant for setups
      where each client may migrate to another physical host, possibly going
      through one or more name changes in the process.

  * Performance: Since collectd is running as a daemon it doesn't spend much
    time starting up again and again. With the exception of the exec plugin no
    processes are forked. Caching in output plugins, such as the rrdtool and
    network plugins, makes sure your resources are used efficiently. Also,
    since collectd is programmed multithreaded it benefits from hyperthreading
    and multicore processors and makes sure that the daemon isn't idle if only
    one plugins waits for an IO-operation to complete.

  * Once set up, hardly any maintenance is necessary. Setup is kept as easy
    as possible and the default values should be okay for most users.


Operation
---------

  * collectd's configuration file can be found at `sysconfdir'/collectd.conf.
    Run `collectd -h' for a list of builtin defaults. See `collectd.conf(5)'
    for a list of options and a syntax description.

  * When the `csv' or `rrdtool' plugins are loaded they'll write the values to
    files. The usual place for these files is beneath `/var/lib/collectd'.

  * When using some of the plugins, collectd needs to run as user root, since
    only root can do certain things, such as craft ICMP packages needed to ping
    other hosts. collectd should NOT be installed setuid root since it can be
    used to overwrite valuable files!

  * Sample scripts to generate graphs reside in `contrib/' in the source
    package or somewhere near `/usr/share/doc/collectd' in most distributions.
    Please be aware that those script are meant as a starting point for your
    own experiments.. Some of them require the `RRDs' Perl module.
    (`librrds-perl' on Debian) If you have written a more sophisticated
    solution please share it with us.

  * The RRAs of the automatically created RRD files depend on the `step'
    and `heartbeat' settings given. If change these settings you may need to
    re-create the files, losing all data. Please be aware of that when changing
    the values and read the rrdtool(1) manpage thoroughly.


collectd and chkrootkit
-----------------------

  If you are using the `dns' plugin chkrootkit(1) will report collectd as a
  packet sniffer ("<iface>: PACKET SNIFFER(/usr/sbin/collectd[<pid>])"). The
  plugin captures all UDP packets on port 53 to analyze the DNS traffic. In
  this case, collectd is a legitimate sniffer and the report should be
  considered to be a false positive. However, you might want to check that
  this really is collectd and not some other, illegitimate sniffer.


Prerequisites
-------------

  To compile collectd from source you will need:

  * Usual suspects: C compiler, linker, preprocessor, make, ...

  * A POSIX-threads (pthread) implementation.
    Since gathering some statistics is slow (network connections, slow devices,
    etc) the collectd is parallelized. The POSIX threads interface is being
    used and should be found in various implementations for hopefully all
    platforms.

  * CoreFoundation.framework and IOKit.framework (optional)
    For compiling on Darwin in general and the `apple_sensors' plugin in
    particular.
    <http://developer.apple.com/corefoundation/>

  * libcurl (optional)
    If you want to use the `apache', `ascent', or `nginx' plugin.
    <http://curl.haxx.se/>

  * libdbi (optional)
    Used by the `dbi' plugin to connect to various databases.
    <http://libdbi.sourceforge.net/>

  * libesmtp (optional)
    For the `notify_email' plugin.
    <http://www.stafford.uklinux.net/libesmtp/>

  * libhal (optional)
    If present, the uuid plugin will check for UUID from HAL.
    <http://hal.freedesktop.org/>

  * libiptc (optional, if not found a version shipped with this distribution
    can be used if the Linux kernel headers are available)
    For querying iptables counters.
    <http://netfilter.org/>

  * libmysqlclient (optional)
    Unsurprisingly used by the `mysql' plugin.
    <http://dev.mysql.com/>

  * libnetlink (optional)
    Used, obviously, for the `netlink' plugin.
    <http://www.linuxfoundation.org/en/Net:Iproute2>

  * libnetsnmp (optional)
    For the `snmp' plugin.
    <http://www.net-snmp.org/>

  * libnotify (optional)
    For the `notify_desktop' plugin.
    <http://www.galago-project.org/>

  * liboping (optional, if not found a version shipped with this distribution
    can be used)
    Used by the `ping' plugin to send and receive ICMP packets.
    <http://verplant.org/liboping/>

  * libowcapi (optional)
    Used by the `onewire' plugin to read values from onewire sensors (or the
    owserver(1) daemon).
    <http://www.owfs.org/>

  * libpcap (optional)
    Used to capture packets by the `dns' plugin.
    <http://www.tcpdump.org/>

  * libpcre (optional)
    Used by the `filter_pcre' plugin.
    <http://www.pcre.org/>

  * libperl (optional)
    Obviously used by the `perl' plugin. The library has to be compiled with
    ithread support (introduced in Perl 5.6.0).
    <http://www.perl.org/>

  * libpq (optional)
    The PostgreSQL C client library used by the `postgresql' plugin.
    <http://www.postgresql.org/>

  * librrd (optional)
    Used by the `rrdtool' and `rrdcached' plugins. The latter requires RRDtool
    client support which was added after version 1.3 of RRDtool. Versions 1.0,
    1.2 and 1.3 are known to work with the `rrdtool' plugin.
    <http://oss.oetiker.ch/rrdtool/>

  * librt, libsocket, libkstat, libdevinfo (optional)
    Various standard Solaris libraries which provide system functions.
    <http://developers.sun.com/solaris/>

  * libsensors (optional)
    To read from `lm_sensors', see the `sensors' plugin.
    <http://www.lm-sensors.org/>

  * libstatgrab (optional)
    Used by various plugins to collect statistics on systems other than Linux
    and/or Solaris.
    <http://www.i-scream.org/libstatgrab/>

  * libupsclient/nut (optional)
    For the `nut' plugin which queries nut's `upsd'.
    <http://networkupstools.org/>

  * libvirt (optional)
    Collect statistics from virtual machines.
    <http://libvirt.org/>

  * libxml2 (optional)
    Parse XML data. This is needed for the `ascent' and `libvirt' plugins.
    <http://xmlsoft.org/>

  * libxmms (optional)
    <http://www.xmms.org/>


Configuring / Compiling / Installing
------------------------------------

  To configure, build and install collectd with the default settings, run
  `./configure && make && make install'.  For detailed, generic instructions
  see INSTALL. For a complete list of configure options and their description,
  run `./configure --help'.

  By default, the configure script will check for all build dependencies and
  disable all plugins whose requirements cannot be fulfilled (any other plugin
  will be enabled). To enable a plugin, install missing dependencies (see
  section `Prerequisites' above) and rerun `configure'. If you specify the
  `--enable-<plugin>' configure option, the script will fail if the depen-
  dencies for the specified plugin are not met. If you specify the
  `--disable-<plugin>' configure option, the plugin will not be built. Both
  options are meant for package maintainers and should not be used in everyday
  situations.

  By default, collectd will be installed into `/opt/collectd'. You can adjust
  this setting by specifying the `--prefix' configure option - see INSTALL for
  details. If you pass DESTDIR=<path> to `make install', <path> will be
  prefixed to all installation directories. This might be useful when creating
  packages for collectd.


Crosscompiling
--------------

  To compile correctly collectd needs to be able to initialize static
  variables to NAN (Not A Number). Some C libraries, especially the GNU
  libc, have a problem with that.

  Luckily, with GCC it's possible to work around that problem: One can define
  NAN as being (0.0 / 0.0) and `isnan' as `f != f'. However, to test this
  ``implementation'' the configure script needs to compile and run a short
  test program. Obviously running a test program when doing a cross-
  compilation is, well, challenging.

  If you run into this problem, you can use the `--with-nan-emulation'
  configure option to force the use of this implementation. We can't promise
  that the compiled binary actually behaves as it should, but since NANs
  are likely never passed to the libm you have a good chance to be lucky.


Contact
-------

  For questions, bugreports, development information and basically all other
  concerns please send an email to collectd's mailinglist at
  <collectd at verplant.org>.

  For live discussion and more personal contact visit us in IRC, we're in
  channel #collectd on freenode.


Author
------

  Florian octo Forster <octo at verplant.org>,
  Sebastian tokkee Harl <sh at tokkee.org>,
  and many contributors (see `AUTHORS').

  Please send bugreports and patches to the mailinglist, see `Contact' above.