Bumped version to 4.0.7; Updated ChangeLog.

[collectd.git] / README

diff --git a/README b/README
index 8d6c7ed..6f59a7a 100644 (file)
--- a/README
+++ b/README
@@ -14,117 +14,185 @@ Features
 
   * collectd is able to collect the following data:
 
 
   * collectd is able to collect the following data:
 

-    - Apache server utilization
-      (Number of bytes transfered, number of requests handled and detailed
-      scoreboard statistics)
+    - apache
+      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)
+    - apcups
+      APC UPS Daemon: UPS charge, load, input/output/battery voltage, etc.

 
 

-    - Apple Sensors
-      (Temperature, fanspeed and voltage sensors of apple computers)
+    - apple_sensors
+      Sensors in Macs running Mac OS X / Darwin: Temperature, fanspeed and
+      voltage sensors.

 
 

-    - Battery
-      (Charge, current and charge of ACPI and PMU based batteries)
+    - battery
+      Batterycharge, -current and voltage of ACPI and PMU based laptop
+      batteries.

 
 

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

 
 

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

 
 

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

 
 

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

 
 

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

 
 

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

 
 

-    - Entropy available
-      (Amount of entropy available to the system)
+    - entropy
+      Amount of entropy available to the system.

 
 

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

 
 

-    - Harddisk temperatures
-      (Uhm, yeah, temperature of harddisks that is ;)
+    - hddtemp
+      Harddisk temperatures using hddtempd.

 
 

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

 
 

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

 
 

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

 
 

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

 
 

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

 
 

-    - Memory utilization
-      (Memory occupied by running processes, page cache, buffer cache and free)
+    - 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»)
+    - multimeter
+      Information provided by serial multimeters, such as the `Metex
+      M-4650CR'.

 
 

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

 
 

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

 
 

-    - NTP Daemon
-      (Local clock drift, offset to peers, etc)
+    - nfs
+      NFS Procedures: Which NFS command were called how often. Only NFSv2 and
+      NFSv3 right now.

 
 

-    - Network UPS tools
-      (UPS current, voltage, power, charge, utilisation, temperature, etc.)
+    - ntp
+      NTP daemon statistics: Local clock drift, offset to peers, etc.

 
 

-    - Ping latency
-      (Time to reach the default gateway or another given host)
+    - nut
+      Network UPS tools: UPS current, voltage, power, charge, utilisation,
+      temperature, etc. See upsd(8).

 
 

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

 
 

-    - Sensors
-      (lm_sensors voltages, temperatures and fan rotation speeds)
+      This plugin is still considered to be experimental and subject to change
+      between minor releases.

 
 

-    - Serial
-      (RX and TX of serial interfaces)
+    - ping
+      Network latency: Time to reach the default gateway or another given
+      host.

 
 

-    - Swap
-      (Pages swapped out onto harddisk or whatever is called `swap' by the OS..)
+    - processes
+      Process counts: Number of running, sleeping, zombie, ... processes.

 
 

-    - Tape
-      (Read and write bytes and operations on tape devices)
+    - sensors
+      System sensors, accessed using lm_sensors: Voltages, temperatures and
+      fan rotation speeds.

 
 

-    - Users
-      (Currently logged in users)
+    - serial
+      RX and TX of serial interfaces. Linux only; needs root privileges.

 
 

-    - VServer
-      (System ressources used by vservers)
+    - swap
+      Pages swapped out onto harddisk or whatever is called `swap' by the OS..

 
 

-    - Wireless
-      (Link quality of wireless cards)
+    - tape
+      Bytes and operations read and written on tape devices. Solaris only.

 
 

-  * Output to CSV- and RRD-files, send values over the network and/or provide a
-    generic interface for use by other means, e. g. a Nagios-plugin.
+    - users
+      Users currently logged in.

 
 

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

 
 

-  * Hardly any maintenance neccessary and setup is trivial.
+    - wireless
+      Link quality of wireless cards. Linux only.

 
 

-  * Extremely easy and failsafe network operation possible.
+  * 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).
+
+    - 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.
+
+  * 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.
+
+    - syslog
+      Logs to the standard UNIX logging mechanism, syslog.
+
+  * 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
 
 
 Operation


@@ -138,19 +206,21 @@ Operation
     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
     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 thing, 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..
+    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.
 
   * 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)
+    (`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'
 
   * The RRAs of the automatically created RRD files depend on the `step'

-    and `heartbeat' settings given. For a list of the default RRAs take a look
-    in the collectd(1) manpage.
+    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.

 
 
 Prerequisites
 
 
 Prerequisites


@@ -162,7 +232,7 @@ Prerequisites
 
   * A POSIX-threads (pthread) implementation.
     Since gathering some statistics is slow (network connections, slow devices,
 
   * A POSIX-threads (pthread) implementation.
     Since gathering some statistics is slow (network connections, slow devices,

-    etc) the collectd is parellelized. The POSIX threads interface is being
+    etc) the collectd is parallelized. The POSIX threads interface is being

     used and should be found in various implementations for hopefully all
     platforms.
 
     used and should be found in various implementations for hopefully all
     platforms.
 


@@ -183,8 +253,8 @@ Prerequisites
 
   * librrd (optional; 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.
 
   * librrd (optional; 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.
-    Alternatively you can chose to write CSV-files (Comma Seperated Values)
+    will send its values via multicast and not create any RRD files itself.
+    Alternatively you can chose to write CSV-files (Comma Separated Values)

     instead.
 
   * libsensors (optional)
     instead.
 
   * libsensors (optional)


@@ -202,11 +272,46 @@ Prerequisites
     Various standard Solaris libraries which provide system functions.
 
   * CoreFoundation.framework and IOKit.framework
     Various standard Solaris libraries which provide system functions.
 
   * CoreFoundation.framework and IOKit.framework

-    For compiling on darwin in general and the `apple_sensors' plugin in
+    For compiling on Darwin in general and the `apple_sensors' plugin in

     particular.
 
     particular.
 

+
+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
 ------
 
 Author
 ------
 

-  Florian octo Forster <octo at verplant.org>
+  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.