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

About
-----

  collectd is a small daemon which collects statistics about a computer's
  usage and writes then into RRD files.


Features
--------

  * collectd is able to collect the following data:

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

    - APC UPS Daemon
      (UPS charge, load, input/output/battery voltage, etc)

    - Apple Sensors
      (Temperature, fanspeed and voltage sensors of apple computers)

    - Battery
      (Charge, current and charge of ACPI and PMU based batteries)

    - CPU utilization
      (Time spent in system, user, nice and idle)

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

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

    - Disk utilization
      (Sectors read/written, number of read/write actions, time spent doing IO)

    - Harddisk temperatures
      (Uhm, yeah, temperature of harddisks that is ;)

    - System load
      (Load average over the last 1, 5 and 15 minutes)

    - Memory utilization
      (Memory occupied by running processes, page cache, buffer cache and free)

    - MySQL server statistics
      (Commands issued, handlers triggered, thread usage, query cache
      utilization and traffic sent/received)

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

    - NTP Daemon
      (Local clock drift, offset to peers, etc)

    - Ping latency
      (Time to reach the default gateway or another given host)

    - Process counts
      (Number of running, sleeping, zombie, ... processes)

    - Sensors
      (System temperatured and fan rotation speeds)

    - Serial
      (RX and TX of serial interfaces)

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

    - Tape
      (Read and write bytes and operations on tape devices)

    - Traffic
      (In/Outbound traffic on the interfaces)

    - Users
      (Currently logged in users)

    - VServer
      (System ressources used by vservers)

    - Wireless
      (Link quality of wireless cards)

  * Performance: Running as a daemon collectd doesn't spend much time in
    startup. Since collectd links against libping, librrd and libsensors it
    doesn't need to start any other processes.

  * Hardly any maintenance neccessary and setup is trivial.

  * Extremely easy and failsafe network operation possible.


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 running collectd writes system statistics in RRD-files. Per default
    they reside in `/var/lib/collectd'.

  * When using the `ping' plugin collectd needs to run as user root, since only
    root can 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)

  * The RRAs of the automatically created RRD files depend on the `step'
    and `heartbeat' settings given on compile time. For a list of the
    default RRAs take a look in the collectd(1) manpage.


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

  To compile collectd from source you will need:

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

  * rrdtool (headers and library; rrdtool 1.0 and 1.2 both work fine)
    If built without `librrd' the resulting binary will be `client only', i.e.
    will send it's values via multicast and not create any RRD files itself.

  * libmysqlclient (optional)

  * lm-sensors (optional)

  * libstatgrab may be used to collect statistics on systems other than Linux
    and/or Solaris. Note that CPU- and disk-statistics, while being provided by
    this library, are not supported in collectd right now..
    <http://www.i-scream.org/libstatgrab/> 

  * libcurl (optional)
    If you want to use the `apache' plugin

  * CoreFoundation.framework and IOKit.framework
    For copiling on darwin in general and the `apple_sensors' plugin in
    particular.

Author
------

  Florian octo Forster <octo at verplant.org>