You can find the answers to these questions on the FAQ page.
  • It doesn't work. Where can I find diagnostic output?
    Version 3.* writes warnings and error messages using the syslog(3) facility. Depending on your system the syslog-daemon writes these messages to files and/or sends them to another host. On most GNU/Linux distributions the place to look at is either /var/log/syslog or /var/log/messages.
    Version 4.0 and later comes with the logfile and syslog plugins which can be used to write status messages to a file or send it to the syslog daemon.
  • Some lines of the config seem to be ignored..?
    Yes, that's a known bug. You probably have one or more white spaces at the end of the lines being ignored.
    This is a bug in the library used by collectd 3.* to parse the configfile. Versions 4.0 and later use a different library and don't have this problem.
  • Can I adjust the interval in which data is collected?
    Yes, since version 3.9.0 this can be set at compiletime. Keep in mind, though, that this will change the layout of the generated RRD-files. Also, clients and servers should have the same setting here to avoid interesting results.
    Version 4.0 allows this setting to be adjusted in the configfile.
  • I try to use the ping-plugin, but keep getting the message "`ping_host_add' failed.". What's the matter?
    In order to generate ICMP packets one needs to open a so called "RAW socket". On most UNIX systems only the superuser (root) may open such sockets.
    In addition, some virtualization environments, such as VServer and Solaris Zones have been reported to cause some trouble.
  • Who receives the multicast traffic?
    I don't know. That entirely depends on your network setup. By default collectd uses "site local" addresses, that should not be routed to outside your AS. If that's really the case is up to you.
  • What does "Invalid value for config option `Mode': `Local'" mean?
    Is means that the mode "Local" is not available. Most likely the "librrd" library wasn't found. If you want to write to RRD-files install "librrd" or, if you already did that, use the --with-rrdtool option of the ./configure-script to point to the right direction.
  • How to I use --with-rrdtool?
    If you installed libraries in a non-standard (or non-system) path you need to specify them when running the configure script. Otherwise it will not find them and build the binaries without linking against the library.
    You need to set the PATH as given to the --prefix option when compiling the library. The script actually looks for the two subdirectories PATH/include and PATH/lib, so check for their existence if things don't work. If, for example, you installed RRDTool in /opt/rrdtool-x.y.z you need to run configure like this:
    $ ./configure --with-rrdtool=/opt/rrdtool-x.y.z
  • The apache-plugin reports the following error: apache: curl_easy_perform failed: Failed writing body. What's wrong?
    The response received was too big and didn't fit into the buffer. Check the URL-option in the configfile. Especially check that the URL ends in "?auto": collectd requires the machine readable output generated by the Apache-plugin mod_status and will not work with anything else.
  • What do the version numbers mean?
    The version numbers consist of three numbers: The major- and minor-number and the patchlevel.
    • Versions with different major-numbers are basically not compatible. This means that the definitions of RRD-files or config-options have been changed or, in general, that the user has to do something in addition to install the new version. This is not nice and avoided when possible, but sometimes necessary to prevent old mistakes to become ancient mistakes. We try to provide migration scripts, though, to make a switch as easy as possible. See the v3 to v4 migration guide for details.
    • Versions with differing minor-numbers are backwards compatible, i. e. you can replace the lower version with the higher one and everything should still work. This means that features are added, but not removed or changed and that the default behavior does not change.
    • Versions with different patchlevels are both, forward- and backwards-compatible, because no new features have been introduced. The only difference between the two versions is one or more bugfixes, so you should generally install the higher version of the two.
  • I enabled the foo plugin using --enable-foo but now the build process fails. What's wrong?
    Since version 4.0.0 a server process doesn't need to load the plugins from which data should be received - in contrast to versions 3.*. This means, that plugins with unmet dependencies no longer have any purpose. So, we moved dependency checking into the configure script, starting with version 4.1.0. I. e. the configure script now automatically disables all plugins with unmet dependencies and enables all plugins whose dependencies are met.
    So, if a plugin is displayed as disabled, it's dependencies are not met. The normal way to get a plugin compiled is to install the missing dependencies and re-run the configure script.
    You can force it to be build using --enable-foo, but you need to know exactly what you are doing. If you do this you're out in the dark, cold woods and totally on your own!
  • The build process fails with "relocation R_X86_64_32 against `a local symbol' can not be used when making a shared object; recompile with -fPIC". What's wrong?
    Many plugins have to be linked against libraries. A few of them (currently iptables, netlink and nut are known to be affected) link against libraries that are only available as "static libraries" in many distributions. Most distributions (e. g. Debian and SuSE GNU/Linux) do not compile static libraries with the "-fPIC" option. Thus they cannot be linked with shared objects compiled with "-fPIC". Some architectures (among them i386) do not seem to care about that and handle it in some (probably magic) way. However, other architectures (mostly 64bit like amd64 or hppa) cannot handle that and thus the compiler aborts with the error message mentioned above.
    To fix this issue, you need a version of the static library compiled with "-fPIC" (or a shared library). Ask your distributor to provide a suitable version of the library or compile it yourself.
    For more detailed information please refer to:
  • Solaris support is broken! The build aborts! Help!
    There are two known issues with Solaris, but both can be fixed relatively easy:
    If you build a 32bit binary, the configure script will (try to) enable LFS. This will result in an error which looks somehow like this:
    config.h:832:1: error: "_FILE_OFFSET_BITS" redefined
    Also, the swap-plugin has some problems of it's own with this:
    swap.c:197: warning: implicit declaration of function 'swapctl'
    swap.c:197: error: 'SC_AINFO' undeclared (first use in this function)
    The solution is to build a 64bit binary! If you build a 64bit binary LFS is not needed and the swap plugin works as intended. To do this, pass the -m64 flag to the compiler (assuming you're using the Sun C compiler.
    Another problem is that by default Sun defines a version of getgrnam_r that isn't POSIX-compatible. To enable POSIX-compatibility pass the _POSIX_PTHREAD_SEMANTICS define to the compiler.
    Putting all together you need to pass the following flags to the configure-script:
    # Sun CC
    $ ./configure CFLAGS="-m64 -mt -D_POSIX_PTHREAD_SEMANTICS"
    Please note that we only test the Sun C compiler ourselves, but GCC may work, too. When using the GCC you need to substitute the -mt flag with the -pthreads flag. So if you use GCC the above invokation of ./configure becomes:
    # GCC
    $ ./configure CFLAGS="-m64 -pthreads -D_POSIX_PTHREAD_SEMANTICS"
    Thanks to Christophe Kalt for sharing his insights :)
  • Why is the CPU usage split up in so many files? Can I change that?
    The short answer is: That is because otherwise backwards compatibility would be impossible and you would have to re-create your files from scratch regularly. And, "no".
    The long answer and explanation of the short answer is: collectd runs on a variety of operating systems. Each operating system has it's own method for accounting CPU states, memory consumption, swap usage, and so on. If all these data sources where in one data set, every new supported operating system or any addition to an already supported operating system would mean that we need to modify the data set. This cannot be done without breaking backwards compatibility.
    To give you a few examples: Sometime in mid-2.6 the Linux kernel added some Xen-patches which provided a new CPU state: "steal time". When adding support for BSD systems we had to add "wired" memory. NFSv4 added some new procedures that NFSv3 didn't have, etc pp.
    That interface traffic has two data sources is different, because every operating system will account received and transmitted bytes. Likewise for the system load: The 1, 5, and 15 minute averages have been like that for ages and it's very unlikely that any weird UNIX does this different.
    Changing the layout of the data is not just a matter of changing the types.db file. That file describes the layout of the data submitted by plugins. The plugins don't need it - they know what data they submit. It's needed by the daemon and writing plugin to know how to store the data. If you mess with the file without knowing what you do, you will most likely end up with the data not being collected at all anymore.
  • Why doesn't collection.cgi draw foo graphs correctly?
    That script is meant as a starting point for own developments, not as a ready to use web frontend for RRD files written by collectd.
    It is just an example, because it's not really usable as it is. And it's not really useable, because we are UNIX developers and don't enjoy doing web stuff much. Working on the daemon is just so much more fun.. ;) So in the best of free / open source traditions: Patches welcome!
    There are alternatives, though. We've heard from various people using Cacti to render the graphs. Sergiusz Pawlowicz of the BBC has written CollectGraph, a macro for the MoinMoin wiki. And of course there's drraw.

Manpage collectd.conf(5)

NAME

collectd.conf - Configuration for the system statistics collection daemon collectd

SYNOPSIS

  BaseDir "/path/to/data/"
  PIDFile "/path/to/pidfile/collectd.pid"
  Server  "123.123.123.123" 12345
  LoadPlugin cpu
  LoadPlugin load
  LoadPlugin ping
  <Plugin ping>
    Host "example.org"
    Host "provider.net"
  </Plugin>

DESCRIPTION

This config file controls how the system statistics collection daemon collectd behaves. The most significant option is LoadPlugin, which controls which plugins to load. These plugins ultimately define collectd's behavior.

The syntax of this config file is similar to the config file of the famous Apache Webserver. Each line contains either a key-value-pair or a section-start or -end. Empty lines and everything after the hash-symbol `#' is ignored. Values are either string, enclosed in double-quotes, (floating-point-)numbers or a boolean expression, i. e. either true or false. String containing of only alphanumeric characters and underscores do not need to be quoted.

The configuration is read and processed in order, i. e. from top to bottom. So the plugins are loaded in the order listed in this config file. It is a good idea to load any logging plugins first in order to catch messages from plugins during configuration. Also, the LoadPlugin option must occur before the <Plugin ...> block.

GLOBAL OPTIONS

BaseDir Directory

Sets the base directory. This is the directory beneath all RRD-files are created. Possibly more subdirectories are created. This is also the working directory for the daemon.

LoadPlugin Plugin

Loads the plugin Plugin. There must be at least one such line or collectd will be mostly useless.

Include Path

If Path points to a file, includes that file. If Path points to a directory, recursively includes all files within that directory and its subdirectories. If the wordexp function is available on your system, shell-like wildcards are expanded before files are included. This means you can use statements like the following:

  Include "/etc/collectd.d/*.conf"

If more than one files are included by a single Include option, the files will be included in lexicographical order (as defined by the strcmp function). Thus, you can e. g. use numbered prefixes to specify the order in which the files are loaded.

To prevent loops and shooting yourself in the foot in interesting ways the nesting is limited to a depth of 8 levels, which should be sufficient for most uses. Since symlinks are followed it is still possible to crash the daemon by looping symlinks. In our opinion significant stupidity should result in an appropriate amount of pain.

It is no problem to have a block like <Plugin foo> in more than one file, but you cannot include files from within blocks.

PIDFile File

Sets where to write the PID file to. This file is overwritten when it exists and deleted when the program is stopped. Some init-scripts might override this setting using the -P command-line option.

PluginDir Directory

Path to the plugins (shared objects) of collectd.

TypesDB File [File ...]

Set one or more files that contain the data-set descriptions. See types.db(5) for a description of the format of this file.

Interval Seconds

Configures the interval in which to query the read plugins. Obviously smaller values lead to a higher system load produced by collectd, while higher values lead to more coarse statistics.

ReadThreads Num

Number of threads to start for reading plugins. The default value is 5, but you may want to increase this if you have more than five plugins that take a long time to read. Mostly those are plugin that do network-IO. Setting this to a value higher than the number of plugins you've loaded is totally useless.

Hostname Name

Sets the hostname that identifies a host. If you omit this setting, the hostname will be determinded using the gethostname(2) system call.

FQDNLookup true|false

If Hostname is determined automatically this setting controls whether or not the daemon should try to figure out the ``fully qualified domain name'', FQDN. This is done using a lookup of the name returned by gethostname.

Using this feature (i. e. setting this option to true) is recommended. However, to preserve backwards compatibility the default is set to false. The sample config file that is installed with makeinstall includes a line which sets this option, though, so that default installations will have this setting enabled.

PLUGIN OPTIONS

Some plugins may register own options. These options must be enclosed in a Plugin-Section. Which options exist depends on the plugin used. Some plugins require external configuration, too. The apache plugin, for example, required mod_status to be configured in the webserver you're going to collect data from. These plugins are listed below as well, even if they don't require any configuration within collectd's configfile.

A list of all plugins and a short summary for each plugin can be found in the README file shipped with the sourcecode and hopefully binary packets as well.

Plugin apache

To configure the apache-plugin you first need to configure the Apache webserver correctly. The Apache-plugin mod_status needs to be loaded and working and the ExtendedStatus directive needs to be enabled. You can use the following snipped to base your Apache config upon:

  ExtendedStatus on
  <IfModule mod_status.c>
    <Location /mod_status>
      SetHandler server-status
    </Location>
  </IfModule>

Since its mod_status module is very similar to Apache's, lighttpd is also supported. It introduces a new field, called BusyServers, to count the number of currently connected clients. This field is also supported.

The following options are accepted by the apache-plugin:

URL http://host/mod_status?auto

Sets the URL of the mod_status output. This needs to be the output generated by ExtendedStatus on and it needs to be the machine readable output generated by appending the ?auto argument.

User Username

Optional user name needed for authentication.

Password Password

Optional password needed for authentication.

VerifyPeer true|false

Enable or disable peer SSL certificate verification. See http://curl.haxx.se/docs/sslcerts.html for details. Enabled by default.

VerifyHost true|false

Enable or disable peer host name verification. If enabled, the plugin checks if the Common Name or a Subject Alternate Name field of the SSL certificate matches the host name provided by the URL option. If this identity check fails, the connection is aborted. Obviously, only works when connecting to a SSL enabled server. Enabled by default.

CACert File

File that holds one or more SSL certificates. If you want to use HTTPS you will possibly need this option. What CA certificates come bundled with libcurl and are checked by default depends on the distribution you use.

Plugin apcups

Host Hostname

Hostname of the host running apcupsd. Defaults to localhost. Please note that IPv6 support has been disabled unless someone can confirm or decline that apcupsd can handle it.

Port Port

TCP-Port to connect to. Defaults to 3551.

Plugin ascent

This plugin collects information about an Ascent server, a free server for the ``World of Warcraft'' game. This plugin gathers the information by fetching the XML status page using libcurl and parses it using libxml2.

The configuration options are the same as for the apache plugin above:

URL http://localhost/ascent/status/

Sets the URL of the XML status output.

User Username

Optional user name needed for authentication.

Password Password

Optional password needed for authentication.

CACert File

File that holds one or more SSL certificates. If you want to use HTTPS you will possibly need this option. What CA certificates come bundled with libcurl and are checked by default depends on the distribution you use.

Plugin cpufreq

This plugin doesn't have any options. It reads /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq (for the first CPU installed) to get the current CPU frequency. If this file does not exist make sure cpufreqd (http://cpufreqd.sourceforge.net/) or a similar tool is installed and an ``cpu governor'' (that's a kernel module) is loaded.

Plugin csv

DataDir Directory

Set the directory to store CSV-files under. Per default CSV-files are generated beneath the daemon's working directory, i. e. the BaseDir.

StoreRates true|false

If set to true, convert counter values to rates. If set to false (the default) counter values are stored as is, i. e. as an increasing integer number.

Plugin df

Device Device

Select partitions based on the devicename.

MountPoint Directory

Select partitions based on the mountpoint.

FSType FSType

Select partitions based on the filesystem type.

IgnoreSelected true|false

Invert the selection: If set to true, all partitions except the ones that match any one of the criteria are collected. By default only selected partitions are collected if a selection is made. If no selection is configured at all, all partitions are selected.

Plugin disk

The disk plugin collects information about the usage of physical disks and logical disks (partitions). Values collected are the number of octets written to and read from a disk or partition, the number of read/write operations issued to the disk and a rather complex ``time'' it took for these commands to be issued.

Using the following two options you can ignore some disks or configure the collection only of specific disks.

Disk Name

Select the disk Name. Whether it is collected or ignored depends on the IgnoreSelected setting, see below. As with other plugins that use the daemon's ignorelist functionality, a string that starts and ends with a slash is interpreted as a regular expression. Examples:

  Disk "sdd"
  Disk "/hda[34]/"
IgnoreSelected true|false

Sets whether selected disks, i. e. the ones matches by any of the Disk statements, are ignored or if all other disks are ignored. The behavior (hopefully) is intuitive: If no Disk option is configured, all disks are collected. If at least one Disk option is given and no IgnoreSelected or set to false, only matching disks will be collected. If IgnoreSelected is set to true, all disks are collected except the ones matched.

Plugin dns

Interface Interface

The dns plugin uses libpcap to capture dns traffic and analyses it. This option sets the interface that should be used. If this option is not set, or set to ``any'', the plugin will try to get packets from all interfaces. This may not work on certain platforms, such as Mac OS X.

IgnoreSource IP-address

Ignore packets that originate from this address.

Plugin email

SocketFile Path

Sets the socket-file which is to be created.

SocketGroup Group

If running as root change the group of the UNIX-socket after it has been created. Defaults to collectd.

SocketPerms Permissions

Change the file permissions of the UNIX-socket after it has been created. The permissions must be given as a numeric, octal value as you would pass to chmod(1). Defaults to 0770.

MaxConns Number

Sets the maximum number of connections that can be handled in parallel. Since this many threads will be started immediately setting this to a very high value will waste valuable resources. Defaults to 5 and will be forced to be at most 16384 to prevent typos and dumb mistakes.

Plugin exec

Please make sure to read collectd-exec(5) before using this plugin. It contains valuable information on when the executable is executed and the output that is expected from it.

Exec User[:[Group]] Executable [<arg> [<arg> ...]]
NotificationExec User[:[Group]] Executable [<arg> [<arg> ...]]

Execute the executable Executable as user User. If the user name is followed by a colon and a group name, the effective group is set to that group. The real group and saved-set group will be set to the default group of that user. If no group is given the effective group ID will be the same as the real group ID.

Please note that in order to change the user and/or group the daemon needs superuser privileges. If the daemon is run as an unprivileged user you must specify the same user/group here. If the daemon is run with superuser privileges, you must supply a non-root user here.

The executable may be followed by optional arguments that are passed to the program. Please note that due to the configuration parsing numbers and boolean values may be changed. If you want to be absolutely sure that something is passed as-is please enclose it in quotes.

The Exec and NotificationExec statements change the semantics of the programs executed, i. e. the data passed to them and the response expected from them. This is documented in great detail in collectd-exec(5).

Plugin hddtemp

To get values from hddtemp collectd connects to localhost (127.0.0.1), port 7634/tcp. The Host and Port options can be used to change these default values, see below. hddtemp has to be running to work correctly. If hddtemp is not running timeouts may appear which may interfere with other statistics..

The hddtemp homepage can be found at http://www.guzu.net/linux/hddtemp.php.

Host Hostname

Hostname to connect to. Defaults to 127.0.0.1.

Port Port

TCP-Port to connect to. Defaults to 7634.

TranslateDevicename true|false

If enabled, translate the disk names to major/minor device numbers (e. g. ``8-0'' for /dev/sda). For backwards compatibility this defaults to true but it's recommended to disable it as it will probably be removed in the next major version.

Plugin interface

Interface Interface

Select this interface. By default these interfaces will then be collected. For a more detailed description see IgnoreSelected below.

IgnoreSelected true|false

If no configuration if given, the traffic-plugin will collect data from all interfaces. This may not be practical, especially for loopback- and similar interfaces. Thus, you can use the Interface-option to pick the interfaces you're interested in. Sometimes, however, it's easier/preferred to collect all interfaces except a few ones. This option enables you to do that: By setting IgnoreSelected to true the effect of Interface is inversed: All selected interfaces are ignored and all other interfaces are collected.

Plugin iptables

Chain Table Chain [Comment|Number [Name]]

Select the rules to count. If only Table and Chain are given, this plugin will collect the counters of all rules which have a comment-match. The comment is then used as type-instance.

If Comment or Number is given, only the rule with the matching comment or the nth rule will be collected. Again, the comment (or the number) will be used as the type-instance.

If Name is supplied, it will be used as the type-instance instead of the comment or the number.

Plugin irq

Irq Irq

Select this irq. By default these irqs will then be collected. For a more detailed description see IgnoreSelected below.

IgnoreSelected true|false

If no configuration if given, the irq-plugin will collect data from all irqs. This may not be practical, especially if no interrupts happen. Thus, you can use the Irq-option to pick the interrupt you're interested in. Sometimes, however, it's easier/preferred to collect all interrupts except a few ones. This option enables you to do that: By setting IgnoreSelected to true the effect of Irq is inversed: All selected interrupts are ignored and all other interrupts are collected.

Plugin libvirt

This plugin allows CPU, disk and network load to be collected for virtualized guests on the machine. This means that these characteristics can be collected for guest systems without installing any software on them - collectd only runs on the hosting system. The statistics are collected through libvirt (http://libvirt.org/).

Only Connection is required.

Connection uri

Connect to the hypervisor given by uri. For example if using Xen use:

 Connection "xen:///"

Details which URIs allowed are given at http://libvirt.org/uri.html.

RefreshInterval seconds

Refresh the list of domains and devices every seconds. The default is 60 seconds. Setting this to be the same or smaller than the Interval will cause the list of domains and devices to be refreshed on every iteration.

Refreshing the devices in particular is quite a costly operation, so if your virtualization setup is static you might consider increasing this. If this option is set to 0, refreshing is disabled completely.

Domain name
BlockDevice name:dev
InterfaceDevice name:dev
IgnoreSelected true|false

Select which domains and devices are collected.

If IgnoreSelected is not given or false then only the listed domains and disk/network devices are collected.

If IgnoreSelected is true then the test is reversed and the listed domains and disk/network devices are ignored, while the rest are collected.

The domain name and device names may use a regular expression, if the name is surrounded by /.../ and collectd was compiled with support for regexps.

The default is to collect statistics for all domains and all their devices.

Example:

 BlockDevice "/:hdb/"
 IgnoreSelected "true"

Ignore all hdb devices on any domain, but other block devices (eg. hda) will be collected.

HostnameFormat name|uuid|hostname|...

When the libvirt plugin logs data, it sets the hostname of the collected data according to this setting. The default is to use the guest name as provided by the hypervisor, which is equal to setting name.

uuid means use the guest's UUID. This is useful if you want to track the same guest across migrations.

hostname means to use the global Hostname setting, which is probably not useful on its own because all guests will appear to have the same name.

You can also specify combinations of these fields. For example name uuid means to concatenate the guest name and UUID (with a literal colon character between, thus ``foo:1234-1234-1234-1234'').

Plugin logfile

LogLevel debug|info|notice|warning|err

Sets the log-level. If, for example, set to notice, then all events with severity notice, warning, or err will be written to the logfile.

Please note that debug is only available if collectd has been compiled with debugging support.

File File

Sets the file to write log messages to. The special strings stdout and stderr can be used to write to the standard output and standard error channels, respectively. This, of course, only makes much sense when collectd is running in foreground- or non-daemon-mode.

Timestamp true|false

Prefix all lines printed by the current time. Defaults to true.

Plugin mbmon

The mbmon plugin uses mbmon to retrieve temperature, voltage, etc.

Be default collectd connects to localhost (127.0.0.1), port 411/tcp. The Host and Port options can be used to change these values, see below. mbmon has to be running to work correctly. If mbmon is not running timeouts may appear which may interfere with other statistics..

mbmon must be run with the -r option (``print TAG and Value format''); Debian's /etc/init.d/mbmon script already does this, other people will need to ensure that this is the case.

Host Hostname

Hostname to connect to. Defaults to 127.0.0.1.

Port Port

TCP-Port to connect to. Defaults to 411.

Plugin memcached

The memcached plugin connects to a memcached server and queries statistics about cache utilization, memory and bandwidth used. http://www.danga.com/memcached/

Host Hostname

Hostname to connect to. Defaults to 127.0.0.1.

Port Port

TCP-Port to connect to. Defaults to 11211.

Plugin mysql

The mysql plugin requires mysqlclient to be installed. It connects to the database when started and keeps the connection up as long as possible. When the connection is interrupted for whatever reason it will try to re-connect. The plugin will complaint loudly in case anything goes wrong.

This plugin issues SHOW STATUS and evaluates Bytes_{received,sent}, Com_* and Handler_* which correspond to mysql_octets.rrd, mysql_commands-*.rrd and mysql_handler-*.rrd. Also, the values of Qcache_* are put in mysql_qcache.rrd and values of Threads_* are put in mysql_threads.rrd. Please refer to the MySQL reference manual, 5.2.4. Server Status Variables for an explanation of these values.

Use the following options to configure the plugin:

Host Hostname

Hostname of the database server. Defaults to localhost.

User Username

Username to use when connecting to the database.

Password Password

Password needed to log into the database.

Database Database

Select this database. Defaults to no database which is a perfectly reasonable option for what this plugin does.

Plugin netlink

The netlink plugin uses a netlink socket to query the Linux kernel about statistics of various interface and routing aspects.

Interface Interface
VerboseInterface Interface

Instruct the plugin to collect interface statistics. This is basically the same as the statistics provided by the interface plugin (see above) but potentially much more detailed.

When configuring with Interface only the basic statistics will be collected, namely octets, packets, and errors. These statistics are collected by the interface plugin, too, so using both at the same time is no benefit.

When configured with VerboseInterface all counters except the basic ones, so that no data needs to be collected twice if you use the interface plugin. This includes dropped packets, received multicast packets, collisions and a whole zoo of differentiated RX and TX errors. You can try the following command to get an idea of what awaits you:

  ip -s -s link list

If Interface is All, all interfaces will be selected.

QDisc Interface [QDisc]
Class Interface [Class]
Filter Interface [Filter]

Collect the octets and packets that pass a certain qdisc, class or filter.

QDiscs and classes are identified by their type and handle (or classid). Filters don't necessarily have a handle, therefore the parent's handle is used. The notation used in collectd differs from that used in tc(1) in that it doesn't skip the major or minor number if it's zero and doesn't print special ids by their name. So, for example, a qdisc may be identified by pfifo_fast-1:0 even though the minor number of all qdiscs is zero and thus not displayed by tc(1).

If QDisc, Class, or Filter is given without the second argument, i. .e. without an identifier, all qdiscs, classes, or filters that are associated with that interface will be collected.

Since a filter itself doesn't necessarily have a handle, the parent's handle is used. This may lead to problems when more than one filter is attached to a qdisc or class. This isn't nice, but we don't know how this could be done any better. If you have a idea, please don't hesitate to tell us.

As with the Interface option you can specify All as the interface, meaning all interfaces.

Here are some examples to help you understand the above text more easily:

  <Plugin netlink>
    VerboseInterface "All"
    QDisc "eth0" "pfifo_fast-1:0"
    QDisc "ppp0"
    Class "ppp0" "htb-1:10"
    Filter "ppp0" "u32-1:0"
  </Plugin>
IgnoreSelected

The behaviour is the same as with all other similar plugins: If nothing is selected at all, everything is collected. If some things are selected using the options described above, only these statistics are collected. If you set IgnoreSelected to true, this behavior is inversed, i. e. the specified statistics will not be collected.

Plugin network

Listen Host [Port]
Server Host [Port]

The Server statement sets the server to send datagrams to. The statement may occur multiple times to send each datagram to multiple destinations.

The Listen statement sets the interfaces to bind to. When multiple statements are found the daemon will bind to multiple interfaces.

The argument Host may be a hostname, an IPv4 address or an IPv6 address. If the argument is a multicast address the daemon will join that multicast group.

If no Listen statement is found the server tries join both, the default IPv6 multicast group and the default IPv4 multicast group. If no Server statement is found the client will try to send data to the IPv6 multicast group first. If that fails the client will try the IPv4 multicast group.

The default IPv6 multicast group is ff18::efc0:4a42. The default IPv4 multicast group is 239.192.74.66.

The optional Port argument sets the port to use. It can either be given using a numeric port number or a service name. If the argument is omitted the default port 25826 is assumed.

TimeToLive 1-255

Set the time-to-live of sent packets. This applies to all, unicast and multicast, and IPv4 and IPv6 packets. The default is to not change this value. That means that multicast packets will be sent with a TTL of 1 (one) on most operating systems.

Forward true|false

If set to true, write packets that were received via the network plugin to the sending sockets. This should only be activated when the Listen- and Server-statements differ. Otherwise packets may be send multiple times to the same multicast group. While this results in more network traffic than necessary it's not a huge problem since the plugin has a duplicate detection, so the values will not loop.

CacheFlush Seconds

For each host/plugin/type combination the network plugin caches the time of the last value being sent or received. Every Seconds seconds the plugin searches and removes all entries that are older than Seconds seconds, thus freeing the unused memory again. Since this process is somewhat expensive and normally doesn't do much, this value should not be too small. The default is 1800 seconds, but setting this to 86400 seconds (one day) will not do much harm either.

Plugin nginx

This plugin collects the number of connections and requests handled by the nginx daemon (speak: engine X), a HTTP and mail server/proxy. It queries the page provided by the ngx_http_stub_status_module module, which isn't compiled by default. Please refer to http://wiki.codemongers.com/NginxStubStatusModule for more information on how to compile and configure nginx and this module.

The following options are accepted by the nginx plugin:

URL http://host/nginx_status

Sets the URL of the ngx_http_stub_status_module output.

User Username

Optional user name needed for authentication.

Password Password

Optional password needed for authentication.

VerifyPeer true|false

Enable or disable peer SSL certificate verification. See http://curl.haxx.se/docs/sslcerts.html for details. Enabled by default.

VerifyHost true|false

Enable or disable peer host name verification. If enabled, the plugin checks if the Common Name or a Subject Alternate Name field of the SSL certificate matches the host name provided by the URL option. If this identity check fails, the connection is aborted. Obviously, only works when connecting to a SSL enabled server. Enabled by default.

CACert File

File that holds one or more SSL certificates. If you want to use HTTPS you will possibly need this option. What CA certificates come bundled with libcurl and are checked by default depends on the distribution you use.

Plugin ntpd

Host Hostname

Hostname of the host running ntpd. Defaults to localhost.

Port Port

UDP-Port to connect to. Defaults to 123.

ReverseLookups true|false

Sets wether or not to perform reverse lookups on peers. Since the name or IP-address may be used in a filename it is recommended to disable reverse lookups. The default is to do reverse lookups to preserve backwards compatibility, though.

Plugin nut

UPS upsname@hostname[:port]

Add a UPS to collect data from. The format is identical to the one accepted by upsc(8).

Plugin perl

This plugin embeds a Perl-interpreter into collectd and provides an interface to collectd's plugin system. See collectd-perl(5) for its documentation.

Plugin ping

Host IP-address

Host to ping periodically. This option may be repeated several times to ping multiple hosts.

TTL 0-255

Sets the Time-To-Live of generated ICMP packets.

Plugin powerdns

The powerdns plugin queries statistics from an authoritative PowerDNS nameserver and/or a PowerDNS recursor. Since both offer a wide variety of values, many of which are probably meaningless to most users, but may be useful for some. So you may chose which values to collect, but if you don't, some reasonable defaults will be collected.

  <Plugin "powerdns">
    <Server "server_name">
      Collect "latency"
      Collect "udp-answers" "udp-queries"
      Socket "/var/run/pdns.controlsocket"
    </Server>
    <Recursor "recursor_name">
      Collect "questions"
      Collect "cache-hits" "cache-misses"
      Socket "/var/run/pdns_recursor.controlsocket"
    </Recursor>
    LocalSocket "/opt/collectd/var/run/collectd-powerdns"
  </Plugin>
Server and Recursor block

The Server block defines one authoritative server to query, the Recursor does the same for an recursing server. The possible options in both blocks are the same, though. The argument defines a name for the server / recursor and is required.

Collect Field

Using the Collect statement you can select which values to collect. Here, you specify the name of the values as used by the PowerDNS servers, e. g. dlg-only-drops, answers10-100.

The method of getting the values differs for Server and Recursor blocks: When querying the server a SHOW * command is issued in any case, because that's the only way of getting multiple values out of the server at once. collectd then picks out the values you have selected. When querying the recursor, a command is generated to query exactly these values. So if you specify invalid fields when querying the recursor, a syntax error may be returned by the daemon and collectd may not collect any values at all.

If no Collect statement is given, the following Server values will be collected:

latency
packetcache-hit
packetcache-miss
packetcache-size
query-cache-hit
query-cache-miss
recursing-answers
recursing-questions
tcp-answers
tcp-queries
udp-answers
udp-queries

The following Recursor values will be collected by default:

noerror-answers
nxdomain-answers
servfail-answers
sys-msec
user-msec
qa-latency
cache-entries
cache-hits
cache-misses
questions

Please note that up to that point collectd doesn't know what values are available on the server and values that are added do not need a change of the mechanism so far. However, the values must be mapped to collectd's naming scheme, which is done using a lookup table that lists all known values. If values are added in the future and collectd does not know about them, you will get an error much like this:

  powerdns plugin: submit: Not found in lookup table: foobar = 42

In this case please file a bug report with the collectd team.

Socket Path

Configures the path to the UNIX domain socket to be used when connecting to the daemon. By default /var/run/pdns.controlsocket will be used for an authoritative server and /var/run/pdns_recursor.controlsocket will be used for the recursor.

LocalSocket Path

Querying the recursor is done using UDP. When using UDP over UNIX domain sockets, the client socket needs a name in the file system, too. You can set this local name to Path using the LocalSocket option. The default is prefix/var/run/collectd-powerdns.

Plugin processes

Process Name

Select more detailed statistics of processes matching this name. The statistics collected for these selected processes are size of the resident segment size (RSS), user- and system-time used, number of processes and number of threads, and minor and major pagefaults.

Plugin rrdtool

You can use the settings StepSize, HeartBeat, RRARows, and XFF to fine-tune your RRD-files. Please read rrdcreate(1) if you encounter problems using these settings. If you don't want to dive into the depths of RRDTool, you can safely ignore these settings.

DataDir Directory

Set the directory to store RRD-files under. Per default RRD-files are generated beneath the daemon's working directory, i. e. the BaseDir.

StepSize Seconds

Force the stepsize of newly created RRD-files. Ideally (and per default) this setting is unset and the stepsize is set to the interval in which the data is collected. Do not use this option unless you absolutely have to for some reason. Setting this option may cause problems with the snmp plugin, the exec plugin or when the daemon is set up to receive data from other hosts.

HeartBeat Seconds

Force the heartbeat of newly created RRD-files. This setting should be unset in which case the heartbeat is set to twice the StepSize which should equal the interval in which data is collected. Do not set this option unless you have a very good reason to do so.

RRARows NumRows

The rrdtool plugin calculates the number of PDPs per CDP based on the StepSize, this setting and a timespan. This plugin creates RRD-files with three times five RRAs, i. e. five RRAs with the CFs MIN, AVERAGE, and MAX. The five RRAs are optimized for graphs covering one hour, one day, one week, one month, and one year.

So for each timespan, it calculates how many PDPs need to be consolidated into one CDP by calculating: number of PDPs = timespan / (stepsize * rrarows)

Bottom line is, set this no smaller than the width of you graphs in pixels. The default is 1200.

RRATimespan Seconds

Adds an RRA-timespan, given in seconds. Use this option multiple times to have more then one RRA. If this option is never used, the built-in default of (3600, 86400, 604800, 2678400, 31622400) is used.

For more information on how RRA-sizes are calculated see RRARows above.

XFF Factor

Set the ``XFiles Factor''. The default is 0.1. If unsure, don't set this option.

CacheFlush Seconds

When the rrdtool plugin uses a cache (by setting CacheTimeout, see below) it writes all values for a certain RRD-file if the oldest value is older than (or equal to) the number of seconds specified. If some RRD-file is not updated anymore for some reason (the computer was shut down, the network is broken, etc.) some values may still be in the cache. If CacheFlush is set, then the entire cache is searched for entries older than CacheTimeout seconds and written to disk every Seconds seconds. Since this is kind of expensive and does nothing under normal circumstances, this value should not be too small. 900 seconds might be a good value, though setting this to 7200 seconds doesn't normally do much harm either.

CacheTimeout Seconds

If this option is set to a value greater than zero, the rrdtool plugin will save values in a cache, as described above. Writing multiple values at once reduces IO-operations and thus lessens the load produced by updating the files. The trade off is that the graphs kind of ``drag behind'' and that more memory is used.

Plugin sensors

The sensors plugin uses lm_sensors to retrieve sensor-values. This means that all the needed modules have to be loaded and lm_sensors has to be configured (most likely by editing /etc/sensors.conf. Read sensors.conf(5) for details.

The lm_sensors homepage can be found at http://secure.netroedge.com/~lm78/.

Sensor chip-bus-address/type-feature

Selects the name of the sensor which you want to collect or ignore, depending on the IgnoreSelected below. For example, the option ``Sensor it8712-isa-0290/voltage-in1'' will cause collectd to gather data for the voltage sensor in1 of the it8712 on the isa bus at the address 0290.

IgnoreSelected true|false

If no configuration if given, the sensors-plugin will collect data from all sensors. This may not be practical, especially for uninteresting sensors. Thus, you can use the Sensor-option to pick the sensors you're interested in. Sometimes, however, it's easier/preferred to collect all sensors except a few ones. This option enables you to do that: By setting IgnoreSelected to true the effect of Sensor is inversed: All selected sensors are ignored and all other sensors are collected.

Plugin snmp

Since the configuration of the snmp plugin is a little more complicated than other plugins, its documentation has been moved to an own manpage, collectd-snmp(5). Please see there for details.

Plugin syslog

LogLevel debug|info|notice|warning|err

Sets the log-level. If, for example, set to notice, then all events with severity notice, warning, or err will be submitted to the syslog-daemon.

Please note that debug is only available if collectd has been compiled with debugging support.

Plugin tail

The tail plugin plugins follows logfiles, just like tail(1) does, parses each line and dispatches found values. What is matched can be configured by the user using (extended) regular expressions, as described in regex(7).

  <Plugin "tail">
    <File "/var/log/exim4/mainlog">
      Instance "exim"
      <Match>
        Regex "S=([1-9][0-9]*)"
        DSType "CounterAdd"
        Type "ipt_bytes"
        Instance "total"
      </Match>
      <Match>
        Regex "\\<R=local_user\\>"
        DSType "CounterInc"
        Type "email_count"
        Instance "local_user"
      </Match>
    </File>
  </Plugin>

The config consists of one or more File blocks, each of which configures one logfile to parse. Within each File block, there are one or more Match blocks, which configure a regular expression to search for.

The Instance option in the File block may be used to set the plugin instance. So in the above example the plugin name tail-foo would be used. This plugin instance is for all Match blocks that follow it, until the next Instance option. This way you can extract several plugin instances from one logfile, handy when parsing syslog and the like.

Each Match block has the following options to describe how the match should be performed:

Regex regex

Sets the regular expression to use for matching against a line. The first subexpression has to match something that can be turned into a number by strtoll(3) or strtod(3), depending on the value of CounterAdd, see below. Because extended regular expressions are used, you do not need to use backslashes for subexpressions! If in doubt, please consult regex(7). Due to collectd's config parsing you need to escape backslashes, though. So if you want to match literal parentheses you need to do the following:

  Regex "SPAM \\(Score: (-?[0-9]+\\.[0-9]+)\\)"
DSType Type

Sets how the values are cumulated. Type is one of:

GaugeAverage

Calculate the average.

GaugeMin

Use the smallest number only.

GaugeMax

Use the greatest number only.

GaugeLast

Use the last number found.

CounterSet

The matched number is a counter. Simply sets the internal counter to this value.

CounterAdd

Add the matched value to the internal counter.

CounterInc

Increase the internal counter by one. This DSType is the only one that does not use the matched subexpression, but simply counts the number of matched lines. Thus, you may use a regular expression without submatch in this case.

As you'd expect the Gauge* types interpret the submatch as a floating point number, using strtod(3). The CounterSet and CounterAdd interpret the submatch as an integer using strtoll(3). CounterInc does not use the submatch at all and it may be omitted in this case.

Type Type

Sets the type used to dispatch this value. Detailed information about types and their configuration can be found in types.db(5).

Instance TypeInstance

This optional setting sets the type instance to use.

Plugin teamspeak2

The teamspeak2 plugin connects to the query port of a teamspeak2 server and polls interesting global and virtual server data. The plugin can query only one physical server but unlimited virtual servers. You can use the following options to configure it:

Host hostname/ip

The hostname or ip which identifies the physical server. Default: 127.0.0.1

Port port

The query port of the physical server. This needs to be a string. Default: ``51234''

Server port

This option has to be added once for every virtual server the plugin should query. If you want to query the virtual server on port 8767 this is what the option would look like:

  Server "8767"

This option, although numeric, needs to be a string, i. e. you must use quotes around it! If no such statement is given only global information will be collected.

Plugin tcpconns

The tcpconns plugin counts the number of currently established TCP connections based on the local port and/or the remote port. Since there may be a lot of connections the default if to count all connections with a local port, for which a listening socket is opened. You can use the following options to fine-tune the ports you are interested in:

ListeningPorts true|false

If this option is set to true, statistics for all local ports for which a listening socket exists are collected. The default depends on LocalPort and RemotePort (see below): If no port at all is specifically selected, the default is to collect listening ports. If specific ports (no matter if local or remote ports) are selected, this option defaults to false, i. e. only the selected ports will be collected unless this option is set to true specifically.

LocalPort Port

Count the connections to a specific local port. This can be used to see how many connections are handled by a specific daemon, e. g. the mailserver. You have to specify the port in numeric form, so for the mailserver example you'd need to set 25.

RemotePort Port

Count the connections to a specific remote port. This is useful to see how much a remote service is used. This is most useful if you want to know how many connections a local service has opened to remote services, e. g. how many connections a mail server or news server has to other mail or news servers, or how many connections a web proxy holds to web servers. You have to give the port in numeric form.

Plugin unixsock

SocketFile Path

Sets the socket-file which is to be created.

SocketGroup Group

If running as root change the group of the UNIX-socket after it has been created. Defaults to collectd.

SocketPerms Permissions

Change the file permissions of the UNIX-socket after it has been created. The permissions must be given as a numeric, octal value as you would pass to chmod(1). Defaults to 0770.

Plugin uuid

This plugin, if loaded, causes the Hostname to be taken from the machine's UUID. The UUID is a universally unique designation for the machine, usually taken from the machine's BIOS. This is most useful if the machine is running in a virtual environment such as Xen, in which case the UUID is preserved across shutdowns and migration.

The following methods are used to find the machine's UUID, in order:

Check /etc/uuid (or UUIDFile).

Check for UUID from HAL (http://www.freedesktop.org/wiki/Software/hal) if present.

Check for UUID from dmidecode / SMBIOS.

Check for UUID from Xen hypervisor.

If no UUID can be found then the hostname is not modified.

UUIDFile Path

Take the UUID from the given file (default /etc/uuid).

Plugin vmem

The vmem plugin collects information about the usage of virtual memory. Since the statistics provided by the Linux kernel are very detailed, they are collected very detailed. However, to get all the details, you have to switch them on manually. Most people just want an overview over, such as the number of pages read from swap space.

Verbose true|false

Enables verbose collection of information. This will start collecting page ``actions'', e. g. page allocations, (de)activations, steals and so on. Part of these statistics are collected on a ``per zone'' basis.

Plugin vserver

This plugin doesn't have any options. VServer support is only available for Linux. It cannot yet be found in a vanilla kernel, though. To make use of this plugin you need a kernel that has VServer support built in, i. e. you need to apply the patches and compile your own kernel, which will then provide the /proc/virtual filesystem that is required by this plugin.

The VServer homepage can be found at http://linux-vserver.org/.

THRESHOLD CONFIGURATION

Starting with version 4.3.0 collectd has support for monitoring. By that we mean that the values are not only stored or sent somewhere, but that they are judged and, if a problem is recognized, acted upon. The only action collectd takes itself is to generate and dispatch a ``notification''. Plugins can register to receive notifications and perform appropriate further actions.

Since systems and what you expect them to do differ a lot, you can configure thresholds for your values freely. This gives you a lot of flexibility but also a lot of responsibility.

Every time a value is out of range a notification is dispatched. This means that the idle percentage of your CPU needs to be less then the configured threshold only once for a notification to be generated. There's no such thing as a moving average or similar - at least not now.

Also, all values that match a threshold are considered to be relevant or ``interesting''. As a consequence collectd will issue a notification if they are not received for twice the last timeout of the values. If, for example, some hosts sends it's CPU statistics to the server every 60 seconds, a notification will be dispatched after about 120 seconds. It may take a little longer because the timeout is checked only once each Interval on the server.

Here is a configuration example to get you started. Read below for more information.

 <Threshold>
   <Type "foo">
     WarningMin    0.00
     WarningMax 1000.00
     FailureMin    0.00
     FailureMax 1200.00
     Invert false
     Instance "bar"
   </Type>
   <Plugin "interface">
     Instance "eth0"
     <Type "if_octets">
       FailureMax 10000000
       DataSource "rx"
     </Type>
   </Plugin>
   <Host "hostname">
     <Type "cpu">
       Instance "idle"
       FailureMin 10
     </Type>
     <Plugin "memory">
       <Type "memory">
         Instance "cached"
         WarningMin 100000000
       </Type>
     </Plugin>
   </Host>
 </Threshold>

There are basically two types of configuration statements: The Host, Plugin, and Type blocks select the value for which a threshold should be configured. The Plugin and Type blocks may be specified further using the Instance option. You can combine the block by nesting the blocks, though they must be nested in the above order, i. e. Host may contain either Plugin and Type blocks, Plugin may only contain Type blocks and Type may not contain other blocks. If multiple blocks apply to the same value the most specific block is used.

The other statements specify the threshold to configure. They must be included in a Type block. Currently the following statements are recognized:

FailureMax Value
WarningMax Value

Sets the upper bound of acceptable values. If unset defaults to positive infinity. If a value is greater than FailureMax a FAILURE notification will be created. If the value is greater than WarningMax but less than (or equal to) FailureMax a WARNING notification will be created.

FailureMin Value
WarningMin Value

Sets the lower bound of acceptable values. If unset defaults to negative infinity. If a value is less than FailureMin a FAILURE notification will be created. If the value is less than WarningMin but greater than (or equal to) FailureMin a WARNING notification will be created.

DataSource DSName

Some data sets have more than one ``data source''. Interesting examples are the if_octets data set, which has received (rx) and sent (tx) bytes and the disk_ops data set, which holds read and write operations. The system load data set, load, even has three data sources: shortterm, midterm, and longterm.

Normally, all data sources are checked against a configured threshold. If this is undesirable, or if you want to specify different limits for each data source, you can use the DataSource option to have a threshold apply only to one data source.

Invert true|false

If set to true the range of acceptable values is inverted, i. e. values between FailureMin and FailureMax (WarningMin and WarningMax) are not okay. Defaults to false.

Persist true|false

Sets how often notifications are generated. If set to true one notification will be generated for each value that is out of the acceptable range. If set to false (the default) then a notification is only generated if a value is out of range but the previous value was okay.

This applies to missing values, too: If set to true a notification about a missing value is generated once every Interval seconds. If set to false only one such notification is generated until the value appears again.

SEE ALSO

collectd(1), collectd-exec(5), collectd-perl(5), collectd-unixsock(5), types.db(5), hddtemp(8), kstat(3KSTAT), mbmon(1), rrdtool(1), sensors(1)

AUTHOR

Florian Forster <octo@verplant.org>