collectd.conf

Langue: en

Autres versions - même langue

Version: 2010-01-14 (fedora - 01/12/10)

Section: 5 (Format de fichier)

Sommaire

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. Lines may be wrapped by using `\' as the last character before the newline. This allows long lines to be split into multiple lines. Quoted strings may be wrapped as well. However, those are treated special in that whitespace at the beginning of the following lines will be ignored, which allows for nicely indenting the wrapped lines.

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 "make install" includes a line which sets this option, though, so that default installations will have this setting enabled.

PreCacheChain ChainName
PostCacheChain ChainName
Configure the name of the ``pre-cache chain'' and the ``post-cache chain''. Please see ``FILTER CONFIGURATION'' below on information on chains and how these setting change the daemon's behavior.

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.
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 bind

Starting with BIND 9.5.0, the most widely used DNS server software provides extensive statistics about queries, responses and lots of other information. The bind plugin retrieves this information that's encoded in XML and provided via HTTP and submits the values to collectd.

To use this plugin, you first need to tell BIND to make this information available. This is done with the "statistics-channels" configuration option:

  statistics-channels {
    inet localhost port 8053;
  };

The configuration follows the grouping that can be seen when looking at the data with an XSLT compatible viewer, such as a modern web browser. It's probably a good idea to make yourself familiar with the provided values, so you can understand what the collected statistics actually mean.

Synopsis:

  <Plugin "bind">
    URL "http://localhost:8053/"
    OpCodes         true
    QTypes          true
  
    ServerStats     true
    ZoneMaintStats  true
    ResolverStats   false
    MemoryStats     true
  
    <View "_default">
      QTypes        true
      ResolverStats true
      CacheRRSets   true
  
      Zone "127.in-addr.arpa/IN"
    </View>
  </Plugin>

The bind plugin accepts the following configuration options:

URL URL
URL from which to retrieve the XML data. If not specified, "http://localhost:8053/" will be used.
OpCodes true|false
When enabled, statistics about the ``OpCodes'', for example the number of "QUERY" packets, are collected.

Default: Enabled.

QTypes true|false
When enabled, the number of incoming queries by query types (for example "A", "MX", "AAAA") is collected.

Default: Enabled.

ServerStats true|false
Collect global server statistics, such as requests received over IPv4 and IPv6, successful queries, and failed updates.

Default: Enabled.

ZoneMaintStats true|false
Collect zone maintenance statistics, mostly information about notifications (zone updates) and zone transfers.

Default: Enabled.

ResolverStats true|false
Collect resolver statistics, i. e. statistics about outgoing requests (e. g. queries over IPv4, lame servers). Since the global resolver counters apparently were removed in BIND 9.5.1 and 9.6.0, this is disabled by default. Use the ResolverStats option within a View ``_default'' block instead for the same functionality.

Default: Disabled.

MemoryStats
Collect global memory statistics.

Default: Enabled.

View Name
Collect statistics about a specific ``view''. BIND can behave different, mostly depending on the source IP-address of the request. These different configurations are called ``views''. If you don't use this feature, you most likely are only interested in the "_default" view.

Within a <View name> block, you can specify which information you want to collect about a view. If no View block is configured, no detailed view statistics will be collected.

QTypes true|false
If enabled, the number of outgoing queries by query type (e. g. "A", "MX") is collected.

Default: Enabled.

ResolverStats true|false
Collect resolver statistics, i. e. statistics about outgoing requests (e. g. queries over IPv4, lame servers).

Default: Enabled.

CacheRRSets true|false
If enabled, the number of entries (``RR sets'') in the view's cache by query type is collected. Negative entries (queries which resulted in an error, for example names that do not exist) are reported with a leading exclamation mark, e. g. ``!A''.

Default: Enabled.

Zone Name
When given, collect detailed information about the given zone in the view. The information collected if very similar to the global ServerStats information (see above).

You can repeat this option to collect detailed information about multiple zones.

By default no detailed zone information is collected.

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. 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.
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 curl

The curl plugin uses the libcurl (<http://curl.haxx.se/>) to read web pages and the match infrastructure (the same code used by the tail plugin) to use regular expressions with the received data.

The following example will read the current value of AMD stock from google's finance page and dispatch the value to collectd.

   <Plugin curl>
     <Page "stock_quotes">
       URL "http://finance.google.com/finance?q=NYSE%3AAMD"
       User "foo"
       Password "bar"
       <Match>
         Regex "<span +class=\"pr\"[^>]*> *([0-9]*\\.[0-9]+) *</span>"
         DSType "GaugeAverage"
         # Note: `stock_value' is not a standard type.
         Type "stock_value"
         Instance "AMD"
       </Match>
     </Page>
   </Plugin>

In the Plugin block, there may be one or more Page blocks, each defining a web page and one or more ``matches'' to be performed on the returned data. The string argument to the Page block is used as plugin instance.

The following options are valid within Page blocks:

URL URL
URL of the web site to retrieve. Since a regular expression will be used to extract information from this data, non-binary data is a big plus here ;)
User Name
Username to use if authorization is required to read the page.
Password Password
Password to use if authorization is required to read the page.
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.
MeasureResponseTime true|false
Measure response time for the request. If this setting is enabled, Match blocks (see below) are optional. Disabled by default.
<Match>
One or more Match blocks that define how to match information in the data returned by "libcurl". The "curl" plugin uses the same infrastructure that's used by the "tail" plugin, so please see the documentation of the "tail" plugin below on how matches are defined. If the MeasureResponseTime option is set to true, Match blocks are optional.

Plugin curl_json

The curl_json plugin uses libcurl (<http://curl.haxx.se/>) and libyajl (<http://www.lloydforge.org/projects/yajl/>) to retrieve JSON data via cURL. This can be used to collect values from CouchDB documents (which are stored JSON notation), for example.

The following example will collect several values from the built-in `_stats' runtime statistics module of CouchDB (<http://wiki.apache.org/couchdb/Runtime_Statistics>).

   <Plugin curl_json>
     <URL "http://localhost:5984/_stats">
       Instance "httpd"
       <Key "httpd/requests/count">
         Type "http_requests"
       </Key>
 
       <Key "httpd_request_methods/*/count">
         Type "http_request_methods"
       </Key>
 
       <Key "httpd_status_codes/*/count">
         Type "http_response_codes"
       </Key>
     </URL>
   </Plugin>

Another CouchDB example: The following example will collect the status values from each database:

   <URL "http://localhost:5984/_all_dbs">
     Instance "dbs"
     <Key "*/doc_count">
       Type "gauge"
     </Key>
     <Key "*/doc_del_count">
       Type "counter"
     </Key>
     <Key "*/disk_size">
       Type "bytes"
     </Key>
   </URL>

In the Plugin block, there may be one or more URL blocks, each defining a URL to be fetched via HTTP (using libcurl) and one or more Key blocks. The Key string argument must be in a path format, which is used to collect a value from a JSON map object. If a path element of Key is the * wildcard, the values for all keys will be collectd.

The following options are valid within URL blocks:

Instance Instance
Sets the plugin instance to Instance.
User Name
Username to use if authorization is required to read the page.
Password Password
Password to use if authorization is required to read the page.
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.

The following options are valid within Key blocks:

Type Type
Sets the type used to dispatch the values to the daemon. Detailed information about types and their configuration can be found in types.db(5). This option is mandatory.
Instance Instance
Type-instance to use. Defaults to the current map key or current string array element value.

Plugin dbi

This plugin uses the dbi library (<http://libdbi.sourceforge.net/>) to connect to various databases, execute SQL statements and read back the results. dbi is an acronym for ``database interface'' in case you were wondering about the name. You can configure how each column is to be interpreted and the plugin will generate one or more data sets from each row returned according to these rules.

Because the plugin is very generic, the configuration is a little more complex than those of other plugins. It usually looks something like this:

   <Plugin dbi>
     <Query "out_of_stock">
       Statement "SELECT category, COUNT(*) AS value FROM products WHERE in_stock = 0 GROUP BY category"
       # Use with MySQL 5.0.0 or later
       MinVersion 50000
       <Result>
         Type "gauge"
         InstancePrefix "out_of_stock"
         InstancesFrom "category"
         ValuesFrom "value"
       </Result>
     </Query>
     <Database "product_information">
       Driver "mysql"
       DriverOption "host" "localhost"
       DriverOption "username" "collectd"
       DriverOption "password" "aZo6daiw"
       DriverOption "dbname" "prod_info"
       SelectDB "prod_info"
       Query "out_of_stock"
     </Database>
   </Plugin>

The configuration above defines one query with one result and one database. The query is then linked to the database with the Query option within the <Database> block. You can have any number of queries and databases and you can also use the Include statement to split up the configuration file in multiple, smaller files. However, the <Query> block must precede the <Database> blocks, because the file is interpreted from top to bottom!

The following is a complete list of options:

Query blocks

Query blocks define SQL statements and how the returned data should be interpreted. They are identified by the name that is given in the opening line of the block. Thus the name needs to be unique. Other than that, the name is not used in collectd.

In each Query block, there is one or more Result blocks. Result blocks define which column holds which value or instance information. You can use multiple Result blocks to create multiple values from one returned row. This is especially useful, when queries take a long time and sending almost the same query again and again is not desirable.

Example:

   <Query "environment">
     Statement "select station, temperature, humidity from environment"
     <Result>
       Type "temperature"
       # InstancePrefix "foo"
       InstancesFrom "station"
       ValuesFrom "temperature"
     </Result>
     <Result>
       Type "humidity"
       InstancesFrom "station"
       ValuesFrom "humidity"
     </Result>
   </Query>

The following options are accepted:

Statement SQL
Sets the statement that should be executed on the server. This is not interpreted by collectd, but simply passed to the database server. Therefore, the SQL dialect that's used depends on the server collectd is connected to.

The query has to return at least two columns, one for the instance and one value. You cannot omit the instance, even if the statement is guaranteed to always return exactly one line. In that case, you can usually specify something like this:

   Statement "SELECT \"instance\", COUNT(*) AS value FROM table"

(That works with MySQL but may not be valid SQL according to the spec. If you use a more strict database server, you may have to select from a dummy table or something.)

Please note that some databases, for example Oracle, will fail if you include a semicolon at the end of the statement.

MinVersion Version
MaxVersion Value
Only use this query for the specified database version. You can use these options to provide multiple queries with the same name but with a slightly different syntax. The plugin will use only those queries, where the specified minimum and maximum versions fit the version of the database in use.

The database version is determined by "dbi_conn_get_engine_version", see the <libdbi documentation> for details. Basically, each part of the version is assumed to be in the range from 00 to 99 and all dots are removed. So version ``4.1.2'' becomes ``40102'', version ``5.0.42'' becomes ``50042''.

Warning: The plugin will use all matching queries, so if you specify multiple queries with the same name and overlapping ranges, weird stuff will happen. Don't to it! A valid example would be something along these lines:

   MinVersion 40000
   MaxVersion 49999
   ...
   MinVersion 50000
   MaxVersion 50099
   ...
   MinVersion 50100
   # No maximum

In the above example, there are three ranges that don't overlap. The last one goes from version ``5.1.0'' to infinity, meaning ``all later versions''. Versions before ``4.0.0'' are not specified.

Type Type
The type that's used for each line returned. See types.db(5) for more details on how types are defined. In short: A type is a predefined layout of data and the number of values and type of values has to match the type definition.

If you specify ``temperature'' here, you need exactly one gauge column. If you specify ``if_octets'', you will need two counter columns. See the ValuesFrom setting below.

There must be exactly one Type option inside each Result block.

InstancePrefix prefix
Prepends prefix to the type instance. If InstancesFrom (see below) is not given, the string is simply copied. If InstancesFrom is given, prefix and all strings returned in the appropriate columns are concatenated together, separated by dashes (``-'').
InstancesFrom column0 [column1 ...]
Specifies the columns whose values will be used to create the ``type-instance'' for each row. If you specify more than one column, the value of all columns will be joined together with dashes (``-'') as separation characters.

The plugin itself does not check whether or not all built instances are different. It's your responsibility to assure that each is unique. This is especially true, if you do not specify InstancesFrom: You have to make sure that only one row is returned in this case.

If neither InstancePrefix nor InstancesFrom is given, the type-instance will be empty.

ValuesFrom column0 [column1 ...]
Names the columns whose content is used as the actual data for the data sets that are dispatched to the daemon. How many such columns you need is determined by the Type setting above. If you specify too many or not enough columns, the plugin will complain about that and no data will be submitted to the daemon.

The actual data type in the columns is not that important. The plugin will automatically cast the values to the right type if it know how to do that. So it should be able to handle integer an floating point types, as well as strings (if they include a number at the beginning).

There must be at least one ValuesFrom option inside each Result block.

Database blocks

Database blocks define a connection to a database and which queries should be sent to that database. Since the used ``dbi'' library can handle a wide variety of databases, the configuration is very generic. If in doubt, refer to libdbi's documentation - we stick as close to the terminology used there.

Each database needs a ``name'' as string argument in the starting tag of the block. This name will be used as ``PluginInstance'' in the values submitted to the daemon. Other than that, that name is not used.

Driver Driver
Specifies the driver to use to connect to the database. In many cases those drivers are named after the database they can connect to, but this is not a technical necessity. These drivers are sometimes referred to as ``DBD'', DataBase Driver, and some distributions ship them in separate packages. Drivers for the ``dbi'' library are developed by the libdbi-drivers project at <http://libdbi-drivers.sourceforge.net/>.

You need to give the driver name as expected by the ``dbi'' library here. You should be able to find that in the documentation for each driver. If you mistype the driver name, the plugin will dump a list of all known driver names to the log.

DriverOption Key Value
Sets driver-specific options. What option a driver supports can be found in the documentation for each driver, somewhere at <http://libdbi-drivers.sourceforge.net/>. However, the options ``host'', ``username'', ``password'', and ``dbname'' seem to be de facto standards.

Unfortunately, drivers are not too keen to report errors when an unknown option is passed to them, so invalid settings here may go unnoticed. This is not the plugin's fault, it will report errors if it gets them from the library / the driver. If a driver complains about an option, the plugin will dump a complete list of all options understood by that driver to the log.

SelectDB Database
In some cases, the database name you connect with is not the database name you want to use for querying data. If this option is set, the plugin will ``select'' (switch to) that database after the connection is established.
Query QueryName
Associates the query named QueryName with this database connection. The query needs to be defined before this statement, i. e. all query blocks you want to refer to must be placed above the database block you want to refer to them from.

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.
ReportByDevice true|false
Report using the device name rather than the mountpoint. i.e. with this false, (the default), it will report a disk as ``root'', but with it true, it will be ``sda1'' (or whichever).
ReportReserved true|false
When enabled, the blocks reserved for root are reported separately. When disabled (the default for backwards compatibility reasons) the reserved space will be included in the ``free'' space.

When disabled, the ``df'' type will be used to store ``free'' and ``used'' space. The mount point or disk name (see option ReportByDevice) is used as type instance in this case (again: backwards compatibility).

When enabled, the type ``df_complex'' is used and three files are created. The mount point or disk name is used as plugin instance and the type instance is set to ``free'', ``reserved'' and ``used'' as appropriate.

Enabling this option is recommended.

ReportInodes true|false
Enables or disables reporting of free, reserved and used inodes. Defaults to inode collection being disabled.

Enable this option if inodes are a scarce resource for you, usually because many small files are stored on the disk. This is a usual scenario for mail transfer agents and web caches.

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.
SelectNumericQueryTypes true|false
Enabled by default, collects unknown (and thus presented as numeric only) query types.

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 filecount

The "filecount" plugin counts the number of files in a certain directory (and its subdirectories) and their combined size. The configuration is very straight forward: 
   <Plugin "filecount">
     <Directory "/var/qmail/queue/mess">
       Instance "qmail-message"
     </Directory>
     <Directory "/var/qmail/queue/todo">
       Instance "qmail-todo"
     </Directory>
     <Directory "/var/lib/php5">
       Instance "php5-sessions"
       Name "sess_*"
     </Directory>
   </Plugin>

The example above counts the number of files in QMail's queue directories and the number of PHP5 sessions. Jfiy: The ``todo'' queue holds the messages that QMail has not yet looked at, the ``message'' queue holds the messages that were classified into ``local'' and ``remote''.

As you can see, the configuration consists of one or more "Directory" blocks, each of which specifies a directory in which to count the files. Within those blocks, the following options are recognized:

Instance Instance
Sets the plugin instance to Instance. That instance name must be unique, but it's your responsibility, the plugin doesn't check for that. If not given, the instance is set to the directory name with all slashes replaced by underscores and all leading underscores removed.
Name Pattern
Only count files that match Pattern, where Pattern is a shell-like wildcard as understood by fnmatch(3). Only the filename is checked against the pattern, not the entire path. In case this makes it easier for you: This option has been named after the -name parameter to find(1).
MTime Age
Count only files of a specific age: If Age is greater than zero, only files that haven't been touched in the last Age seconds are counted. If Age is a negative number, this is inversed. For example, if -60 is specified, only files that have been modified in the last minute will be counted.

The number can also be followed by a ``multiplier'' to easily specify a larger timespan. When given in this notation, the argument must in quoted, i. e. must be passed as string. So the -60 could also be written as ``-1m'' (one minute). Valid multipliers are "s" (second), "m" (minute), "h" (hour), "d" (day), "w" (week), and "y" (year). There is no ``month'' multiplier. You can also specify fractional numbers, e. g. ``0.5d'' is identical to ``12h''.

Size Size
Count only files of a specific size. When Size is a positive number, only files that are at least this big are counted. If Size is a negative number, this is inversed, i. e. only files smaller than the absolute value of Size are counted.

As with the MTime option, a ``multiplier'' may be added. For a detailed description see above. Valid multipliers here are "b" (byte), "k" (kilobyte), "m" (megabyte), "g" (gigabyte), "t" (terabyte), and "p" (petabyte). Please note that there are 1000 bytes in a kilobyte, not 1024.

Recursive true|false
Controls whether or not to recurse into subdirectories. Enabled by default.

Plugin GenericJMX

The GenericJMX plugin is written in Java and therefore documented in collectd-java(5).

Plugin gmond

The gmond plugin received the multicast traffic sent by gmond, the statistics collection daemon of Ganglia. Mappings for the standard ``metrics'' are built-in, custom mappings may be added via Metric blocks, see below.

Synopsis:

  <Plugin "gmond">
    MCReceiveFrom "239.2.11.71" "8649"
    <Metric "swap_total">
      Type "swap"
      TypeInstance "total"
      DataSource "value"
    </Metric>
    <Metric "swap_free">
      Type "swap"
      TypeInstance "free"
      DataSource "value"
    </Metric>
  </Plugin>

The following metrics are built-in:

*
load_one, load_five, load_fifteen
*
cpu_user, cpu_system, cpu_idle, cpu_nice, cpu_wio
*
mem_free, mem_shared, mem_buffers, mem_cached, mem_total
*
bytes_in, bytes_out
*
pkts_in, pkts_out

Available configuration options:

MCReceiveFrom MCGroup [Port]
Sets sets the multicast group and UDP port to which to subscribe.

Default: 239.2.11.71 / 8649

<Metric Name>
These blocks add a new metric conversion to the internal table. Name, the string argument to the Metric block, is the metric name as used by Ganglia.
Type Type
Type to map this metric to. Required.
TypeInstance Instance
Type-instance to use. Optional.
DataSource Name
Data source to map this metric to. If the configured type has exactly one data source, this is optional. Otherwise the option is required.

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 inverted: All selected interfaces are ignored and all other interfaces are collected.

Plugin ipmi

Sensor Sensor
Selects sensors to collect or to ignore, depending on IgnoreSelected.
IgnoreSelected true|false
If no configuration if given, the ipmi plugin will collect data from all sensors found of type ``temperature'', ``voltage'', ``current'' and ``fanspeed''. This option enables you to do that: By setting IgnoreSelected to true the effect of Sensor is inverted: All selected sensors are ignored and all other sensors are collected.
NotifySensorAdd true|false
If a sensor appears after initialization time of a minute a notification is sent.
NotifySensorRemove true|false
If a sensor disappears a notification is sent.
NotifySensorNotPresent true|false
If you have for example dual power supply and one of them is (un)plugged then a notification is sent.

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 inverted: All selected interrupts are ignored and all other interrupts are collected.

Plugin java

The Java plugin makes it possible to write extensions for collectd in Java. This section only discusses the syntax and semantic of the configuration options. For more in-depth information on the Java plugin, please read collectd-java(5).

Synopsis:

  <Plugin "java">
    JVMArg "-verbose:jni"
    JVMArg "-Djava.class.path=/opt/collectd/lib/collectd/bindings/java"
    LoadPlugin "org.collectd.java.Foobar"
    <Plugin "org.collectd.java.Foobar">
      # To be parsed by the plugin
    </Plugin>
  </Plugin>

Available configuration options:

JVMArg Argument
Argument that is to be passed to the Java Virtual Machine (JVM). This works exactly the way the arguments to the java binary on the command line work. Execute "java --help" for details.

Please note that all these options must appear before (i. e. above) any other options! When another option is found, the JVM will be started and later options will have to be ignored!

LoadPlugin JavaClass
Instantiates a new JavaClass object. The constructor of this object very likely then registers one or more callback methods with the server.

See collectd-java(5) for details.

When the first such option is found, the virtual machine (JVM) is created. This means that all JVMArg options must appear before (i. e. above) all LoadPlugin options!

Plugin Name
The entire block is passed to the Java plugin as an org.collectd.api.OConfigItem object.

For this to work, the plugin has to register a configuration callback first, see ``config callback'' in collectd-java(5). This means, that the Plugin block must appear after the appropriate LoadPlugin block. Also note, that Name depends on the (Java) plugin registering the callback and is completely independent from the JavaClass argument passed to LoadPlugin.

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.

Note: There is no need to notify the daemon after moving or removing the log file (e. g. when rotating the logs). The plugin reopens the file for each line it writes.

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 memcachec

The "memcachec plugin" connects to a memcached server, queries one or more given pages and parses the returned data according to user specification. The matches used are the same as the matches used in the "curl" and "tail" plugins.

In order to talk to the memcached server, this plugin uses the libmemcached library. Please note that there is another library with a very similar name, libmemcache (notice the missing `d'), which is not applicable.

Synopsis of the configuration:

  <Plugin "memcachec">
    <Page "plugin_instance">
      Server "localhost"
      Key "page_key"
      <Match>
        Regex "(\\d+) bytes sent"
        DSType CounterAdd
        Type "ipt_octets"
        Instance "type_instance"
      </Match>
    </Page>
  </Plugin>

The configuration options are:

<Page Name>
Each Page block defines one page to be queried from the memcached server. The block requires one string argument which is used as plugin instance.
Server Address
Sets the server address to connect to when querying the page. Must be inside a Page block.
Key Key
When connected to the memcached server, asks for the page Key.
<Match>
Match blocks define which strings to look for and how matches substrings are interpreted. For a description of match blocks, please see ``Plugin tail''.

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 one or more databases 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 the MySQL "SHOW STATUS" / "SHOW GLOBAL STATUS" command and collects information about MySQL network traffic, executed statements, requests, the query cache and threads by evaluating the "Bytes_{received,sent}", "Com_*", "Handler_*", "Qcache_*" and "Threads_*" return values. Please refer to the MySQL reference manual, 5.1.6. Server Status Variables for an explanation of these values.

Optionally, master and slave statistics may be collected in a MySQL replication setup. In that case, information about the synchronization state of the nodes are collected by evaluating the "Position" return value of the "SHOW MASTER STATUS" command and the "Seconds_Behind_Master", "Read_Master_Log_Pos" and "Exec_Master_Log_Pos" return values of the "SHOW SLAVE STATUS" command. See the MySQL reference manual, 12.5.5.21 SHOW MASTER STATUS Syntax and 12.5.5.31 SHOW SLAVE STATUS Syntax for details.

Synopsis:

   <Plugin mysql>
     <Database foo>
       Host "hostname"
       User "username"
       Password "password"
       Port "3306"
       MasterStats true
     </Database>
 
     <Database bar>
       Host "localhost"
       Socket "/var/run/mysql/mysqld.sock"
       SlaveStats true
       SlaveNotifications true
     </Database>
   </Plugin>

A Database block defines one connection to a MySQL database. It accepts a single argument which specifies the name of the database. None of the other options are required. MySQL will use default values as documented in the section ``mysql_real_connect()'' in the MySQL reference manual.

Host Hostname
Hostname of the database server. Defaults to localhost.
User Username
Username to use when connecting to the database. The user does not have to be granted any privileges (which is synonym to granting the "USAGE" privilege). Any existing MySQL user will do.
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.
Port Port
TCP-port to connect to. The port must be specified in its numeric form, but it must be passed as a string nonetheless. For example: 
   Port "3306"

If Host is set to localhost (the default), this setting has no effect. See the documentation for the "mysql_real_connect" function for details.

Socket Socket
Specifies the path to the UNIX domain socket of the MySQL server. This option only has any effect, if Host is set to localhost (the default). Otherwise, use the Port option above. See the documentation for the "mysql_real_connect" function for details.
MasterStats true|false
SlaveStats true|false
Enable the collection of master / slave statistics in a replication setup.
SlaveNotifications true|false
If enabled, the plugin sends a notification if the replication slave I/O and / or SQL threads are not running.

Plugin netapp

The netapp plugin can collect various performance and capacity informations from a NetApp filer using the NetApp API.

Please note that NetApp has a wide line of products and a lot of different software versions for each of these products. This plugin was developed for a NetApp FAS3040 running OnTap 7.2.3P8 and tested on FAS2050 7.3.1.1L1, FAS3140 7.2.5.1 and FAS3020 7.2.4P9. It should work for most combinations of model and software version but it is very hard to test this. If you have used this plugin with other models and/or software version, feel free to send us a mail to tell us about the results, even if it's just a short ``It works''.

To collect these data collectd will log in to the NetApp via HTTP(S) and HTTP basic authentication.

Do not use a regular user for this! Create a special collectd user with just the minimum of capabilities needed. The user only needs the ``login-http-admin'' capability as well as a few more depending on which data will be collected. Required capabilities are documented below.

Synopsis

  <Plugin "netapp">
    <Host "netapp1.example.com">
     Protocol      "https"
     Address       "10.0.0.1"
     Port          443
     User          "username"
     Password      "aef4Aebe"
     Interval      30
     
     <WAFL>
       Interval 30
       GetNameCache   true
       GetDirCache    true
       GetBufferCache true
       GetInodeCache  true
     </WAFL>
     
     <Disks>
       Interval 30
       GetBusy true
     </Disks>
     
     <VolumePerf>
       Interval 30
       GetIO      "volume0"
       IgnoreSelectedIO      false
       GetOps     "volume0"
       IgnoreSelectedOps     false
       GetLatency "volume0"
       IgnoreSelectedLatency false
     </VolumePerf>
     
     <VolumeUsage>
       Interval 30
       GetCapacity "vol0"
       GetCapacity "vol1"
       IgnoreSelectedCapacity false
       GetSnapshot "vol1"
       GetSnapshot "vol3"
       IgnoreSelectedSnapshot false
     </VolumeUsage>
     
     <System>
       Interval 30
       GetCPULoad     true
       GetInterfaces  true
       GetDiskOps     true
       GetDiskIO      true
     </System>
    </Host>
  </Plugin>

The netapp plugin accepts the following configuration options:

Host Name
A host block defines one NetApp filer. It will appear in collectd with the name you specify here which does not have to be its real name nor its hostname.
Protocol httpd|http
The protocol collectd will use to query this host.

Optional

Type: string

Default: https

Valid options: http, https

Address Address
The hostname or IP address of the host.

Optional

Type: string

Default: The ``host'' block's name.

Port Port
The TCP port to connect to on the host.

Optional

Type: integer

Default: 80 for protocol ``http'', 443 for protocol ``https''

User User
Password Password
The username and password to use to login to the NetApp.

Mandatory

Type: string

Interval Interval
TODO

The following options decide what kind of data will be collected. You can either use them as a block and fine tune various parameters inside this block, use them as a single statement to just accept all default values, or omit it to not collect any data.

The following options are valid inside all blocks:

Interval Seconds
Collect the respective statistics every Seconds seconds. Defaults to the host specific setting.

The System block

This will collect various performance data about the whole system.

Note: To get this data the collectd user needs the ``api-perf-object-get-instances'' capability.

Interval Seconds
Collect disk statistics every Seconds seconds.
GetCPULoad true|false
If you set this option to true the current CPU usage will be read. This will be the average usage between all CPUs in your NetApp without any information about individual CPUs.

Note: These are the same values that the NetApp CLI command ``sysstat'' returns in the ``CPU'' field.

Optional

Type: boolean

Default: true

Result: Two value lists of type ``cpu'', and type instances ``idle'' and ``system''.

GetInterfaces true|false
If you set this option to true the current traffic of the network interfaces will be read. This will be the total traffic over all interfaces of your NetApp without any information about individual interfaces.

Note: This is the same values that the NetApp CLI command ``sysstat'' returns in the ``Net kB/s'' field.

Or is it?

Optional

Type: boolean

Default: true

Result: One value list of type ``if_octects''.

GetDiskIO true|false
If you set this option to true the current IO throughput will be read. This will be the total IO of your NetApp without any information about individual disks, volumes or aggregates.

Note: This is the same values that the NetApp CLI command ``sysstat'' returns in the ``Disk kB/s'' field.

Optional

Type: boolean

Default: true

Result: One value list of type ``disk_octets''.

GetDiskOps true|false
If you set this option to true the current number of HTTP, NFS, CIFS, FCP, iSCSI, etc. operations will be read. This will be the total number of operations on your NetApp without any information about individual volumes or aggregates.

Note: These are the same values that the NetApp CLI command ``sysstat'' returns in the ``NFS'', ``CIFS'', ``HTTP'', ``FCP'' and ``iSCSI'' fields.

Optional

Type: boolean

Default: true

Result: A variable number of value lists of type ``disk_ops_complex''. Each type of operation will result in one value list with the name of the operation as type instance.

The WAFL block

This will collect various performance data about the WAFL file system. At the moment this just means cache performance.

Note: To get this data the collectd user needs the ``api-perf-object-get-instances'' capability.

Note: The interface to get these values is classified as ``Diagnostics'' by NetApp. This means that it is not guaranteed to be stable even between minor releases.

Interval Seconds
Collect disk statistics every Seconds seconds.
GetNameCache true|false
Optional

Type: boolean

Default: true

Result: One value list of type ``cache_ratio'' and type instance ``name_cache_hit''.

GetDirCache true|false
Optional

Type: boolean

Default: true

Result: One value list of type ``cache_ratio'' and type instance ``find_dir_hit''.

GetInodeCache true|false
Optional

Type: boolean

Default: true

Result: One value list of type ``cache_ratio'' and type instance ``inode_cache_hit''.

GetBufferCache true|false
Note: This is the same value that the NetApp CLI command ``sysstat'' returns in the ``Cache hit'' field.

Optional

Type: boolean

Default: true

Result: One value list of type ``cache_ratio'' and type instance ``buf_hash_hit''.

The Disks block

This will collect performance data about the individual disks in the NetApp.

Note: To get this data the collectd user needs the ``api-perf-object-get-instances'' capability.

Interval Seconds
Collect disk statistics every Seconds seconds.
GetBusy true|false
If you set this option to true the busy time of all disks will be calculated and the value of the busiest disk in the system will be written.

Note: This is the same values that the NetApp CLI command ``sysstat'' returns in the ``Disk util'' field. Probably.

Optional

Type: boolean

Default: true

Result: One value list of type ``percent'' and type instance ``disk_busy''.

The VolumePerf block

This will collect various performance data about the individual volumes.

You can select which data to collect about which volume using the following options. They follow the standard ignorelist semantic.

Note: To get this data the collectd user needs the api-perf-object-get-instances capability.

Interval Seconds
Collect volume performance data every Seconds seconds.
GetIO Volume
GetOps Volume
GetLatency Volume
Select the given volume for IO, operations or latency statistics collection. The argument is the name of the volume without the "/vol/" prefix.

Since the standard ignorelist functionality is used here, you can use a string starting and ending with a slash to specify regular expression matching: To match the volumes ``vol0'', ``vol2'' and ``vol7'', you can use this regular expression:

   GetIO "/^vol[027]$/"

If no regular expression is specified, an exact match is required. Both, regular and exact matching are case sensitive.

If no volume was specified at all for either of the three options, that data will be collected for all available volumes.

IgnoreSelectedIO true|false
IgnoreSelectedOps true|false
IgnoreSelectedLatency true|false
When set to true, the volumes selected for IO, operations or latency statistics collection will be ignored and the data will be collected for all other volumes.

When set to false, data will only be collected for the specified volumes and all other volumes will be ignored.

If no volumes have been specified with the above Get* options, all volumes will be collected regardless of the IgnoreSelected* option.

Defaults to false

The VolumeUsage block

This will collect capacity data about the individual volumes.

Note: To get this data the collectd user needs the api-volume-list-info capability.

Interval Seconds
Collect volume usage statistics every Seconds seconds.
GetCapacity VolumeName
The current capacity of the volume will be collected. This will result in two to four value lists, depending on the configuration of the volume. All data sources are of type ``df_complex'' with the name of the volume as plugin_instance.

There will be type_instances ``used'' and ``free'' for the number of used and available bytes on the volume. If the volume has some space reserved for snapshots, a type_instance ``snap_reserved'' will be available. If the volume has SIS enabled, a type_instance ``sis_saved'' will be available. This is the number of bytes saved by the SIS feature.

Note: The current NetApp API has a bug that results in this value being reported as a 32 bit number. This plugin tries to guess the correct number which works most of the time. If you see strange values here, bug NetApp support to fix this.

Repeat this option to specify multiple volumes.

IgnoreSelectedCapacity true|false
Specify whether to collect only the volumes selected by the GetCapacity option or to ignore those volumes. IgnoreSelectedCapacity defaults to false. However, if no GetCapacity option is specified at all, all capacities will be selected anyway.
GetSnapshot VolumeName
Select volumes from which to collect snapshot information.

Usually, the space used for snapshots is included in the space reported as ``used''. If snapshot information is collected as well, the space used for snapshots is subtracted from the used space.

To make things even more interesting, it is possible to reserve space to be used for snapshots. If the space required for snapshots is less than that reserved space, there is ``reserved free'' and ``reserved used'' space in addition to ``free'' and ``used''. If the space required for snapshots exceeds the reserved space, that part allocated in the normal space is subtracted from the ``used'' space again.

Repeat this option to specify multiple volumes.

IgnoreSelectedSnapshot
Specify whether to collect only the volumes selected by the GetSnapshot option or to ignore those volumes. IgnoreSelectedSnapshot defaults to false. However, if no GetSnapshot option is specified at all, all capacities will be selected anyway.
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 inverted, i. e. the specified statistics will not be collected.

Plugin network

The Network plugin sends data to a remote instance of collectd, receives data from a remote instance, or both at the same time. Data which has been received from the network is usually not transmitted again, but this can be actived, see the Forward option below.

The default IPv6 multicast group is "ff18::efc0:4a42". The default IPv4 multicast group is 239.192.74.66. The default UDP port is 25826.

Both, Server and Listen can be used as single option or as block. When used as block, given options are valid for this socket only. For example:

  <Plugin "network">
    Server "collectd.internal.tld"
    <Server "collectd.external.tld">
      SecurityLevel "sign"
      Username "myhostname"
      Password "ohl0eQue"
    </Server>
  </Plugin>
<Server Host [Port]>
The Server statement/block sets the server to send datagrams to. The statement may occur multiple times to send each datagram to multiple destinations.

The argument Host may be a hostname, an IPv4 address or an IPv6 address. The optional second argument specifies a port number or a service name. If not given, the default, 25826, is used.

The following options are recognized within Server blocks:

SecurityLevel Encrypt|Sign|None
Set the security you require for network communication. When the security level has been set to Encrypt, data sent over the network will be encrypted using AES-256. The integrity of encrypted packets is ensured using SHA-1. When set to Sign, transmitted data is signed using the HMAC-SHA-256 message authentication code. When set to None, data is sent without any security.

This feature is only available if the network plugin was linked with libgcrypt.

Username Username
Sets the username to transmit. This is used by the server to lookup the password. See AuthFile below. All security levels except None require this setting.

This feature is only available if the network plugin was linked with libgcrypt.

Password Password
Sets a password (shared secret) for this socket. All security levels except None require this setting.

This feature is only available if the network plugin was linked with libgcrypt.

<Listen Host [Port]>
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. The optional second argument specifies a port number or a service name. If not given, the default, 25826, is used.

The following options are recognized within "<Listen>" blocks:

SecurityLevel Encrypt|Sign|None
Set the security you require for network communication. When the security level has been set to Encrypt, only encrypted data will be accepted. The integrity of encrypted packets is ensured using SHA-1. When set to Sign, only signed and encrypted data is accepted. When set to None, all data will be accepted. If an AuthFile option was given (see below), encrypted data is decrypted if possible.

This feature is only available if the network plugin was linked with libgcrypt.

AuthFile Filename
Sets a file in which usernames are mapped to passwords. These passwords are used to verify signatures and to decrypt encrypted network packets. If SecurityLevel is set to None, this is optional. If given, signed data is verified and encrypted packets are decrypted. Otherwise, signed data is accepted without checking the signature and encrypted data cannot be decrypted. For the other security levels this option is mandatory.

The file format is very simple: Each line consists of a username followed by a colon and any number of spaces followed by the password. To demonstrate, an example file could look like this:

   user0: foo
   user1: bar

Each time a packet is received, the modification time of the file is checked using stat(2). If the file has been changed, the contents is re-read. While the file is being read, it is locked using fcntl(2).

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.
MaxPacketSize 1024-65535
Set the maximum size for datagrams received over the network. Packets larger than this will be truncated.
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.
ReportStats true|false
The network plugin cannot only receive and send statistics, it can also create statistics about itself. Collected data included the number of received and sent octets and packets, the length of the receive queue and the number of values handled. When set to true, the Network plugin will make these statistics available. Defaults to false.

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 notify_desktop

This plugin sends a desktop notification to a notification daemon, as defined in the Desktop Notification Specification. To actually display the notifications, notification-daemon is required and collectd has to be able to access the X server.

The Desktop Notification Specification can be found at <http://www.galago-project.org/specs/notification/>.

OkayTimeout timeout
WarningTimeout timeout
FailureTimeout timeout
Set the timeout, in milliseconds, after which to expire the notification for "OKAY", "WARNING" and "FAILURE" severities respectively. If zero has been specified, the displayed notification will not be closed at all - the user has to do so herself. These options default to 5000. If a negative number has been specified, the default is used as well.

Plugin notify_email

The notify_email plugin uses the ESMTP library to send notifications to a configured email address.

libESMTP is available from <http://www.stafford.uklinux.net/libesmtp/>.

Available configuration options:

From Address
Email address from which the emails should appear to come from.

Default: "root@localhost"

Recipient Address
Configures the email address(es) to which the notifications should be mailed. May be repeated to send notifications to multiple addresses.

At least one Recipient must be present for the plugin to work correctly.

SMTPServer Hostname
Hostname of the SMTP server to connect to.

Default: "localhost"

SMTPPort Port
TCP port to connect to.

Default: 25

SMTPUser Username
Username for ASMTP authentication. Optional.
SMTPPassword Password
Password for ASMTP authentication. Optional.
Subject Subject
Subject-template to use when sending emails. There must be exactly two string-placeholders in the subject, given in the standard printf(3) syntax, i. e. %s. The first will be replaced with the severity, the second with the hostname.

Default: "Collectd notify: %s@%s"

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 olsrd

The olsrd plugin connects to the TCP port opened by the txtinfo plugin of the Optimized Link State Routing daemon and reads information about the current state of the meshed network.

The following configuration options are understood:

Host Host
Connect to Host. Defaults to ``localhost''.
Port Port
Specifies the port to connect to. This must be a string, even if you give the port as a number rather than a service name. Defaults to ``2006''.
CollectLinks No|Summary|Detail
Specifies what information to collect about links, i. e. direct connections of the daemon queried. If set to No, no information is collected. If set to Summary, the number of links and the average of all link quality (LQ) and neighbor link quality (NLQ) values is calculated. If set to Detail LQ and NLQ are collected per link.

Defaults to Detail.

CollectRoutes No|Summary|Detail
Specifies what information to collect about routes of the daemon queried. If set to No, no information is collected. If set to Summary, the number of routes and the average metric and ETX is calculated. If set to Detail metric and ETX are collected per route.

Defaults to Summary.

CollectTopology No|Summary|Detail
Specifies what information to collect about the global topology. If set to No, no information is collected. If set to Summary, the number of links in the entire topology and the average link quality (LQ) is calculated. If set to Detail LQ and NLQ are collected for each link in the entire topology.

Defaults to Summary.

Plugin onewire

EXPERIMENTAL! See notes below.

The "onewire" plugin uses the owcapi library from the owfs project <http://owfs.org/> to read sensors connected via the onewire bus.

Currently only temperature sensors (sensors with the family code 10, e. g. DS1820, DS18S20, DS1920) can be read. If you have other sensors you would like to have included, please send a sort request to the mailing list.

Hubs (the DS2409 chips) are working, but read the note, why this plugin is experimental, below.

Device Device
Sets the device to read the values from. This can either be a ``real'' hardware device, such as a serial port or an USB port, or the address of the owserver(1) socket, usually localhost:4304.

Though the documentation claims to automatically recognize the given address format, with version 2.7p4 we had to specify the type explicitly. So with that version, the following configuration worked for us:

   <Plugin onewire>
     Device "-s localhost:4304"
   </Plugin>

This directive is required and does not have a default value.

Sensor Sensor
Selects sensors to collect or to ignore, depending on IgnoreSelected, see below. Sensors are specified without the family byte at the beginning, to you'd use "F10FCA000800", and not include the leading 10. family byte and point.
IgnoreSelected true|false
If no configuration if given, the onewire plugin will collect data from all sensors found. This may not be practical, especially if sensors are added and removed regularly. Sometimes, however, it's easier/preferred to collect only specific sensors or all sensors except a few specified ones. This option enables you to do that: By setting IgnoreSelected to true the effect of Sensor is inverted: All selected interfaces are ignored and all other interfaces are collected.
Interval Seconds
Sets the interval in which all sensors should be read. If not specified, the global Interval setting is used.

EXPERIMENTAL! The "onewire" plugin is experimental, because it doesn't yet work with big setups. It works with one sensor being attached to one controller, but as soon as you throw in a couple more senors and maybe a hub or two, reading all values will take more than ten seconds (the default interval). We will probably add some separate thread for reading the sensors and some cache or something like that, but it's not done yet. We will try to maintain backwards compatibility in the future, but we can't promise. So in short: If it works for you: Great! But keep in mind that the config might change, though this is unlikely. Oh, and if you want to help improving this plugin, just send a short notice to the mailing list. Thanks :)

Plugin openvpn

The OpenVPN plugin reads a status file maintained by OpenVPN and gathers traffic statistics about connected clients.

To set up OpenVPN to write to the status file periodically, use the --status option of OpenVPN. Since OpenVPN can write two different formats, you need to set the required format, too. This is done by setting --status-version to 2.

So, in a nutshell you need:

   openvpn $OTHER_OPTIONS \
     --status "/var/run/openvpn-status" 10 \
     --status-version 2

Available options:

StatusFile File
Specifies the location of the status file.
Compression true|false
Sets whether or not statistics about the compression used by OpenVPN should be collected. This information is only available in single mode. Enabled by default.

Plugin oracle

The ``oracle'' plugin uses the OracleAX Call Interface (OCI) to connect to an OracleAX Database and lets you execute SQL statements there. It is very similar to the ``dbi'' plugin, because it was written around the same time. See the ``dbi'' plugin's documentation above for details. 
   <Plugin oracle>
     <Query "out_of_stock">
       Statement "SELECT category, COUNT(*) AS value FROM products WHERE in_stock = 0 GROUP BY category"
       <Result>
         Type "gauge"
         # InstancePrefix "foo"
         InstancesFrom "category"
         ValuesFrom "value"
       </Result>
     </Query>
     <Database "product_information">
       ConnectID "db01"
       Username "oracle"
       Password "secret"
       Query "out_of_stock"
     </Database>
   </Plugin>

Query blocks

The Query blocks are handled identically to the Query blocks of the ``dbi'' plugin. Please see its documentation above for details on how to specify queries.

Database blocks

Database blocks define a connection to a database and which queries should be sent to that database. Each database needs a ``name'' as string argument in the starting tag of the block. This name will be used as ``PluginInstance'' in the values submitted to the daemon. Other than that, that name is not used.

ConnectID ID
Defines the ``database alias'' or ``service name'' to connect to. Usually, these names are defined in the file named "$ORACLE_HOME/network/admin/tnsnames.ora".
Username Username
Username used for authentication.
Password Password
Password used for authentication.
Query QueryName
Associates the query named QueryName with this database connection. The query needs to be defined before this statement, i. e. all query blocks you want to refer to must be placed above the database block you want to refer to them from.

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

The Ping plugin starts a new thread which sends ICMP ``ping'' packets to the configured hosts periodically and measures the network latency. Whenever the "read" function of the plugin is called, it submits the average latency, the standard deviation and the drop rate for each host.

Available configuration options:

Host IP-address
Host to ping periodically. This option may be repeated several times to ping multiple hosts.
Interval Seconds
Sets the interval in which to send ICMP echo packets to the configured hosts. This is not the interval in which statistics are queries from the plugin but the interval in which the hosts are ``pinged''. Therefore, the setting here should be smaller than or equal to the global Interval setting. Fractional times, such as ``1.24'' are allowed.

Default: 1.0

Timeout Seconds
Time to wait for a response from the host to which an ICMP packet had been sent. If a reply was not received after Seconds seconds, the host is assumed to be down or the packet to be dropped. This setting must be smaller than the Interval setting above for the plugin to work correctly. Fractional arguments are accepted.

Default: 0.9

TTL 0-255
Sets the Time-To-Live of generated ICMP packets.
SourceAddress host
Sets the source address to use. host may either be a numerical network address or a network hostname.
Device name
Sets the outgoing network device to be used. name has to specify an interface name (e. g. "eth0"). This might not be supported by all operating systems.
MaxMissed Packets
Trigger a DNS resolv after the host has not replied to Packets packets. This enables the use of dynamic DNS services (like dyndns.org) with the ping plugin.

Default: -1 (disabled)

Plugin postgresql

The "postgresql" plugin queries statistics from PostgreSQL databases. It keeps a persistent connection to all configured databases and tries to reconnect if the connection has been interrupted. A database is configured by specifying a Database block as described below. The default statistics are collected from PostgreSQL's statistics collector which thus has to be enabled for this plugin to work correctly. This should usually be the case by default. See the section ``The Statistics Collector'' of the PostgreSQL Documentation for details.

By specifying custom database queries using a Query block as described below, you may collect any data that is available from some PostgreSQL database. This way, you are able to access statistics of external daemons which are available in a PostgreSQL database or use future or special statistics provided by PostgreSQL without the need to upgrade your collectd installation.

The PostgreSQL Documentation manual can be found at <http://www.postgresql.org/docs/manuals/>.

   <Plugin postgresql>
     <Query magic>
       Statement "SELECT magic FROM wizard WHERE host = $1;"
       Param hostname
       <Result>
         Type gauge
         InstancePrefix "magic"
         ValuesFrom magic
       </Result>
     </Query>
 
     <Query rt36_tickets>
       Statement "SELECT COUNT(type) AS count, type \
                         FROM (SELECT CASE \
                                      WHEN resolved = 'epoch' THEN 'open' \
                                      ELSE 'resolved' END AS type \
                                      FROM tickets) type \
                         GROUP BY type;"
       <Result>
         Type counter
         InstancePrefix "rt36_tickets"
         InstancesFrom "type"
         ValuesFrom "count"
       </Result>
     </Query>
 
     <Database foo>
       Host "hostname"
       Port "5432"
       User "username"
       Password "secret"
       SSLMode "prefer"
       KRBSrvName "kerberos_service_name"
       Query magic
     </Database>
 
     <Database bar>
       Service "service_name"
       Query backend # predefined
       Query rt36_tickets
     </Database>
   </Plugin>

The Query block defines one database query which may later be used by a database definition. It accepts a single mandatory argument which specifies the name of the query. The names of all queries have to be unique (see the MinVersion and MaxVersion options below for an exception to this rule). The following configuration options are available to define the query:

In each Query block, there is one or more Result blocks. Result blocks define how to handle the values returned from the query. They define which column holds which value and how to dispatch that value to the daemon. Multiple Result blocks may be used to extract multiple values from a single query.

Statement sql query statement
Specify the sql query statement which the plugin should execute. The string may contain the tokens $1, $2, etc. which are used to reference the first, second, etc. parameter. The value of the parameters is specified by the Param configuration option - see below for details. To include a literal $ character followed by a number, surround it with single quotes (').

Any SQL command which may return data (such as "SELECT" or "SHOW") is allowed. Note, however, that only a single command may be used. Semicolons are allowed as long as a single non-empty command has been specified only.

The returned lines will be handled separately one after another.

Query sql query statement
This is a deprecated synonym for Statement. It will be removed in version 5 of collectd.
Param hostname|database|username|interval
Specify the parameters which should be passed to the SQL query. The parameters are referred to in the SQL query as $1, $2, etc. in the same order as they appear in the configuration file. The value of the parameter is determined depending on the value of the Param option as follows:
hostname
The configured hostname of the database connection. If a UNIX domain socket is used, the parameter expands to ``localhost''.
database
The name of the database of the current connection.
username
The username used to connect to the database.
interval
The interval collectd is using (as specified by the Interval option).

Please note that parameters are only supported by PostgreSQL's protocol version 3 and above which was introduced in version 7.4 of PostgreSQL.
Type type
The type name to be used when dispatching the values. The type describes how to handle the data and where to store it. See types.db(5) for more details on types and their configuration. The number and type of values (as selected by the ValuesFrom option) has to match the type of the given name.

This option is required inside a Result block.

InstancePrefix prefix
InstancesFrom column0 [column1 ...]
Specify how to create the ``TypeInstance'' for each data set (i. e. line). InstancePrefix defines a static prefix that will be prepended to all type instances. InstancesFrom defines the column names whose values will be used to create the type instance. Multiple values will be joined together using the hyphen ("-") as separation character.

The plugin itself does not check whether or not all built instances are different. It is your responsibility to assure that each is unique.

Both options are optional. If none is specified, the type instance will be empty.

ValuesFrom column0 [column1 ...]
Names the columns whose content is used as the actual data for the data sets that are dispatched to the daemon. How many such columns you need is determined by the Type setting as explained above. If you specify too many or not enough columns, the plugin will complain about that and no data will be submitted to the daemon.

The actual data type, as seen by PostgreSQL, is not that important as long as it represents numbers. The plugin will automatically cast the values to the right type if it know how to do that. For that, it uses the strtoll(3) and strtod(3) functions, so anything supported by those functions is supported by the plugin as well.

This option is required inside a Result block and may be specified multiple times. If multiple ValuesFrom options are specified, the columns are read in the given order.

Column type [type instance]
This is a deprecated alternative to a Result block. It will be removed in version 5 of collectd. It is equivalent to the following Result block: 
   <Result>
     Type I<type>
     InstancePrefix I<type instance>
     ValuesFrom I<name of the x. column>
   </Result>

The order of the Column options defines which columns of the query result should be used. The first option specifies the data found in the first column, the second option that of the second column, and so on.

MinVersion version
MaxVersion version
Specify the minimum or maximum version of PostgreSQL that this query should be used with. Some statistics might only be available with certain versions of PostgreSQL. This allows you to specify multiple queries with the same name but which apply to different versions, thus allowing you to use the same configuration in a heterogeneous environment.

The version has to be specified as the concatenation of the major, minor and patch-level versions, each represented as two-decimal-digit numbers. For example, version 8.2.3 will become 80203.

MinPGVersion version
MaxPGVersion version
These are deprecated synonyms for MinVersion and MaxVersion respectively. They will be removed in version 5 of collectd.

The following predefined queries are available (the definitions can be found in the postgresql_default.conf file which, by default, is available at "prefix/share/collectd/"):

backends
This query collects the number of backends, i. e. the number of connected clients.
transactions
This query collects the numbers of committed and rolled-back transactions of the user tables.
queries
This query collects the numbers of various table modifications (i. e. insertions, updates, deletions) of the user tables.
query_plans
This query collects the numbers of various table scans and returned tuples of the user tables.
table_states
This query collects the numbers of live and dead rows in the user tables.
disk_io
This query collects disk block access counts for user tables.
disk_usage
This query collects the on-disk size of the database in bytes.

The Database block defines one PostgreSQL database for which to collect statistics. It accepts a single mandatory argument which specifies the database name. None of the other options are required. PostgreSQL will use default values as documented in the section ``CONNECTING TO A DATABASE'' in the psql(1) manpage. However, be aware that those defaults may be influenced by the user collectd is run as and special environment variables. See the manpage for details.

Host hostname
Specify the hostname or IP of the PostgreSQL server to connect to. If the value begins with a slash, it is interpreted as the directory name in which to look for the UNIX domain socket.

This option is also used to determine the hostname that is associated with a collected data set. If it has been omitted or either begins with with a slash or equals localhost it will be replaced with the global hostname definition of collectd. Any other value will be passed literally to collectd when dispatching values. Also see the global Hostname and FQDNLookup options.

Port port
Specify the TCP port or the local UNIX domain socket file extension of the server.
User username
Specify the username to be used when connecting to the server.
Password password
Specify the password to be used when connecting to the server.
SSLMode disable|allow|prefer|require
Specify whether to use an SSL connection when contacting the server. The following modes are supported:
disable
Do not use SSL at all.
allow
First, try to connect without using SSL. If that fails, try using SSL.
prefer (default)
First, try to connect using SSL. If that fails, try without using SSL.
require
Use SSL only.
KRBSrvName kerberos_service_name
Specify the Kerberos service name to use when authenticating with Kerberos 5 or GSSAPI. See the sections ``Kerberos authentication'' and ``GSSAPI'' of the PostgreSQL Documentation for details.
Service service_name
Specify the PostgreSQL service name to use for additional parameters. That service has to be defined in pg_service.conf and holds additional connection parameters. See the section ``The Connection Service File'' in the PostgreSQL Documentation for details.
Query query
Specify a query which should be executed for the database connection. This may be any of the predefined or user-defined queries. If no such option is given, it defaults to ``backends'', ``transactions'', ``queries'', ``query_plans'', ``table_states'', ``disk_io'' and ``disk_usage''. Else, the specified queries are used only.

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 "${localstatedir}/run/pdns.controlsocket" will be used for an authoritative server and "${localstatedir}/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, io data (where available) and minor and major pagefaults.
ProcessMatch name regex
Similar to the Process option this allows to select more detailed statistics of processes matching the specified regex (see regex(7) for details). The statistics of all matching processes are summed up and dispatched to the daemon using the specified name as an identifier. This allows to ``group'' several processes together. name must not contain slashes.

Plugin protocols

Collects a lot of information about various network protocols, such as IP, TCP, UDP, etc.

Available configuration options:

Value Selector
Selects whether or not to select a specific value. The string being matched is of the form "Protocol:ValueName", where Protocol will be used as the plugin instance and ValueName will be used as type instance. An example of the string being used would be "Tcp:RetransSegs".

You can use regular expressions to match a large number of values with just one configuration option. To select all ``extended'' TCP values, you could use the following statement:

   Value "/^TcpExt:/"

Whether only matched values are selected or all matched values are ignored depends on the IgnoreSelected. By default, only matched values are selected. If no value is configured at all, all values will be selected.

IgnoreSelected true|false
If set to true, inverts the selection made by Value, i. e. all matching values will be ignored.

Plugin python

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

Plugin routeros

The "routeros" plugin connects to a device running RouterOS, the Linux-based operating system for routers by MikroTik. The plugin uses librouteros to connect and reads information about the interfaces and wireless connections of the device. The configuration supports querying multiple routers: 
   <Plugin "routeros">
     <Router>
       Host "router0.example.com"
       User "collectd"
       Password "secr3t"
       CollectInterface true
     </Router>
     <Router>
       Host "router1.example.com"
       User "collectd"
       Password "5ecret"
       CollectInterface true
       CollectRegistrationTable true
     </Router>
   </Plugin>

As you can see above, the configuration of the routeros plugin consists of one or more <Router> blocks. Within each block, the following options are understood:

Host Host
Hostname or IP-address of the router to connect to.
Port Port
Port name or port number used when connecting. If left unspecified, the default will be chosen by librouteros, currently ``8728''. This option expects a string argument, even when a numeric port number is given.
User User
Use the user name User to authenticate. Defaults to ``admin''.
Password Password
Set the password used to authenticate.
CollectInterface true|false
When set to true, interface statistics will be collected for all interfaces present on the device. Defaults to false.
CollectRegistrationTable true|false
When set to true, information about wireless LAN connections will be collected. Defaults to false.

Plugin rrdcached

The "rrdcached" plugin uses the RRDtool accelerator daemon, rrdcached(1), to store values to RRD files in an efficient manner. The combination of the "rrdcached" plugin and the "rrdcached" daemon is very similar to the way the "rrdtool" plugin works (see below). The added abstraction layer provides a number of benefits, though: Because the cache is not within "collectd" anymore, it does not need to be flushed when "collectd" is to be restarted. This results in much shorter (if any) gaps in graphs, especially under heavy load. Also, the "rrdtool" command line utility is aware of the daemon so that it can flush values to disk automatically when needed. This allows to integrate automated flushing of values into graphing solutions much more easily.

There are disadvantages, though: The daemon may reside on a different host, so it may not be possible for "collectd" to create the appropriate RRD files anymore. And even if "rrdcached" runs on the same host, it may run in a different base directory, so relative paths may do weird stuff if you're not careful.

So the recommended configuration is to let "collectd" and "rrdcached" run on the same host, communicating via a UNIX domain socket. The DataDir setting should be set to an absolute path, so that a changed base directory does not result in RRD files being created / expected in the wrong place.

DaemonAddress Address
Address of the daemon as understood by the "rrdc_connect" function of the RRD library. See rrdcached(1) for details. Example: 
   <Plugin "rrdcached">
     DaemonAddress "unix:/var/run/rrdcached.sock"
   </Plugin>
DataDir Directory
Set the base directory in which the RRD files reside. If this is a relative path, it is relative to the working base directory of the "rrdcached" daemon! Use of an absolute path is recommended.
CreateFiles true|false
Enables or disables the creation of RRD files. If the daemon is not running locally, or DataDir is set to a relative path, this will not work as expected. Default is true.

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.
WritesPerSecond Updates
When collecting many statistics with collectd and the "rrdtool" plugin, you will run serious performance problems. The CacheFlush setting and the internal update queue assert that collectd continues to work just fine even under heavy load, but the system may become very unresponsive and slow. This is a problem especially if you create graphs from the RRD files on the same machine, for example using the "graph.cgi" script included in the "contrib/collection3/" directory.

This setting is designed for very large setups. Setting this option to a value between 25 and 80 updates per second, depending on your hardware, will leave the server responsive enough to draw graphs even while all the cached values are written to disk. Flushed values, i. e. values that are forced to disk by the FLUSH command, are not effected by this limit. They are still written as fast as possible, so that web frontends have up to date data when generating graphs.

For example: If you have 100,000 RRD files and set WritesPerSecond to 30 updates per second, writing all values to disk will take approximately 56 minutes. Together with the flushing ability that's integrated into ``collection3'' you'll end up with a responsive and fast system, up to date graphs and basically a ``backup'' of your values every hour.

RandomTimeout Seconds
When set, the actual timeout for each value is chosen randomly between CacheTimeout-RandomTimeout and CacheTimeout+RandomTimeout. The intention is to avoid high load situations that appear when many values timeout at the same time. This is especially a problem shortly after the daemon starts, because all values were added to the internal cache at roughly the same time.

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 inverted: 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 table

The "table plugin" provides generic means to parse tabular data and dispatch user specified values. Values are selected based on column numbers. For example, this plugin may be used to get values from the Linux proc(5) filesystem or CSV (comma separated values) files. 
   <Plugin table>
     <Table "/proc/slabinfo">
       Instance "slabinfo"
       Separator " "
       <Result>
         Type gauge
         InstancePrefix "active_objs"
         InstancesFrom 0
         ValuesFrom 1
       </Result>
       <Result>
         Type gauge
         InstancePrefix "objperslab"
         InstancesFrom 0
         ValuesFrom 4
       </Result>
     </Table>
   </Plugin>

The configuration consists of one or more Table blocks, each of which configures one file to parse. Within each Table block, there are one or more Result blocks, which configure which data to select and how to interpret it.

The following options are available inside a Table block:

Instance instance
If specified, instance is used as the plugin instance. So, in the above example, the plugin name "table-slabinfo" would be used. If omitted, the filename of the table is used instead, with all special characters replaced with an underscore ("_").
Separator string
Any character of string is interpreted as a delimiter between the different columns of the table. A sequence of two or more contiguous delimiters in the table is considered to be a single delimiter, i. e. there cannot be any empty columns. The plugin uses the strtok_r(3) function to parse the lines of a table - see its documentation for more details. This option is mandatory.

A horizontal tab, newline and carriage return may be specified by "\\t", "\\n" and "\\r" respectively. Please note that the double backslashes are required because of collectd's config parsing.

The following options are available inside a Result block:

Type type
Sets the type used to dispatch the values to the daemon. Detailed information about types and their configuration can be found in types.db(5). This option is mandatory.
InstancePrefix prefix
If specified, prepend prefix to the type instance. If omitted, only the InstancesFrom option is considered for the type instance.
InstancesFrom column0 [column1 ...]
If specified, the content of the given columns (identified by the column number starting at zero) will be used to create the type instance for each row. Multiple values (and the instance prefix) will be joined together with dashes (-) as separation character. If omitted, only the InstancePrefix option is considered for the type instance.

The plugin itself does not check whether or not all built instances are different. ItaXXs your responsibility to assure that each is unique. This is especially true, if you do not specify InstancesFrom: You have to make sure that the table only contains one row.

If neither InstancePrefix nor InstancesFrom is given, the type instance will be empty.

ValuesFrom column0 [column1 ...]
Specifies the columns (identified by the column numbers starting at zero) whose content is used as the actual data for the data sets that are dispatched to the daemon. How many such columns you need is determined by the Type setting above. If you specify too many or not enough columns, the plugin will complain about that and no data will be submitted to the daemon. The plugin uses strtoll(3) and strtod(3) to parse counter and gauge values respectively, so anything supported by those functions is supported by the plugin as well. This option is mandatory.

Plugin tail

The "tail plugin" 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 "counter"
         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 ted

The TED plugin connects to a device of ``The Energy Detective'', a device to measure power consumption. These devices are usually connected to a serial (RS232) or USB port. The plugin opens a configured device and tries to read the current energy readings. For more information on TED, visit <http://www.theenergydetective.com/>.

Available configuration options:

Device Path
Path to the device on which TED is connected. collectd will need read and write permissions on that file.

Default: /dev/ttyUSB0

Retries Num
Apparently reading from TED is not that reliable. You can therefore configure a number of retries here. You only configure the retries here, to if you specify zero, one reading will be performed (but no retries if that fails); if you specify three, a maximum of four readings are performed. Negative values are illegal.

Default: 0

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 thermal

ForceUseProcfs true|false
By default, the "thermal" plugin tries to read the statistics from the Linux "sysfs" interface. If that is not available, the plugin falls back to the "procfs" interface. By setting this option to true, you can force the plugin to use the latter. This option defaults to false.
Device Device
Selects the name of the thermal device that you want to collect or ignore, depending on the value of the IgnoreSelected option. This option may be used multiple times to specify a list of devices.
IgnoreSelected true|false
Invert the selection: If set to true, all devices except the ones that match the device names specified by the Device option are collected. By default only selected devices are collected if a selection is made. If no selection is configured at all, all devices are selected.

Plugin tokyotyrant

The "tokyotyrant plugin" connects to a TokyoTyrant server and collects a couple metrics: number of records, and database size on disk.
Host Hostname/IP
The hostname or ip which identifies the server. Default: 127.0.0.1
Port Service/Port
The query port of the server. This needs to be a string, even if the port is given in its numeric form. Default: 1978

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/>.

Note: The traffic collected by this plugin accounts for the amount of traffic passing a socket which might be a lot less than the actual on-wire traffic (e. g. due to headers and retransmission). If you want to collect on-wire traffic you could, for example, use the logging facilities of iptables to feed data for the guest IPs into the iptables plugin.

Plugin write_http

This output plugin submits values to an http server by POST them using the PUTVAL plain-text protocol. Each destination you want to post data to needs to have one URL block, within which the destination can be configured further, for example by specifying authentication data.

Synopsis:

  <Plugin "write_http">
    <URL "http://example.com/post-collectd">
      User "collectd"
      Password "weCh3ik0"
    </URL>
  </Plugin>

URL blocks need one string argument which is used as the URL to which data is posted. The following options are understood within URL blocks.

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.
Format Command|JSON
Format of the output to generate. If set to Command, will create output that is understood by the Exec and UnixSock plugins. When set to JSON, will create output in the JavaScript Object Notation (JSON).

Defaults to Command.

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.

When a value comes within range again or is received after it was missing, an ``OKAY-notification'' is dispatched.

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.

Percentage true|false
If set to true, the minimum and maximum values given are interpreted as percentage value, relative to the other data sources. This is helpful for example for the ``df'' type, where you may want to issue a warning when less than 5 % of the total space is available. Defaults to false.

FILTER CONFIGURATION

Starting with collectd 4.6 there is a powerful filtering infrastructure implemented in the daemon. The concept has mostly been copied from ip_tables, the packet filter infrastructure for Linux. We'll use a similar terminology, so that users that are familiar with iptables feel right at home.

Terminology

The following are the terms used in the remainder of the filter configuration documentation. For an ASCII-art schema of the mechanism, see ``General structure'' below.
Match
A match is a criteria to select specific values. Examples are, of course, the name of the value or it's current value.

Matches are implemented in plugins which you have to load prior to using the match. The name of such plugins starts with the ``match_'' prefix.

Target
A target is some action that is to be performed with data. Such actions could, for example, be to change part of the value's identifier or to ignore the value completely.

Some of these targets are built into the daemon, see ``Built-in targets'' below. Other targets are implemented in plugins which you have to load prior to using the target. The name of such plugins starts with the ``target_'' prefix.

Rule
The combination of any number of matches and at least one target is called a rule. The target actions will be performed for all values for which all matches apply. If the rule does not have any matches associated with it, the target action will be performed for all values.
Chain
A chain is a list of rules and possibly default targets. The rules are tried in order and if one matches, the associated target will be called. If a value is handled by a rule, it depends on the target whether or not any subsequent rules are considered or if traversal of the chain is aborted, see ``Flow control'' below. After all rules have been checked, the default targets will be executed.

General structure

The following shows the resulting structure: 
  +---------+
  ! Chain   !
  +---------+
       !
       V
  +---------+  +---------+  +---------+  +---------+
  ! Rule    !->! Match   !->! Match   !->! Target  !
  +---------+  +---------+  +---------+  +---------+
       !
       V
  +---------+  +---------+  +---------+
  ! Rule    !->! Target  !->! Target  !
  +---------+  +---------+  +---------+
       !
       V
       :
       :
       !
       V
  +---------+  +---------+  +---------+
  ! Rule    !->! Match   !->! Target  !
  +---------+  +---------+  +---------+
       !
       V
  +---------+
  ! Default !
  ! Target  !
  +---------+

Flow control

There are four ways to control which way a value takes through the filter mechanism:
jump
The built-in jump target can be used to ``call'' another chain, i. e. process the value with another chain. When the called chain finishes, usually the next target or rule after the jump is executed.
stop
The stop condition, signaled for example by the built-in target stop, causes all processing of the value to be stopped immediately.
return
Causes processing in the current chain to be aborted, but processing of the value generally will continue. This means that if the chain was called via Jump, the next target or rule after the jump will be executed. If the chain was not called by another chain, control will be returned to the daemon and it may pass the value to another chain.
continue
Most targets will signal the continue condition, meaning that processing should continue normally. There is no special built-in target for this condition.

Synopsis

The configuration reflects this structure directly: 
  PostCacheChain "PostCache"
  <Chain "PostCache">
    <Rule "ignore_mysql_show">
      <Match "regex">
        Plugin "^mysql$"
        Type "^mysql_command$"
        TypeInstance "^show_"
      </Match>
      <Target "stop">
      </Target>
    </Rule>
    <Target "write">
      Plugin "rrdtool"
    </Target>
  </Chain>

The above configuration example will ignore all values where the plugin field is ``mysql'', the type is ``mysql_command'' and the type instance begins with ``show_''. All other values will be sent to the "rrdtool" write plugin via the default target of the chain. Since this chain is run after the value has been added to the cache, the MySQL "show_*" command statistics will be available via the "unixsock" plugin.

List of configuration options

PreCacheChain ChainName
PostCacheChain ChainName
Configure the name of the ``pre-cache chain'' and the ``post-cache chain''. The argument is the name of a chain that should be executed before and/or after the values have been added to the cache.

To understand the implications, it's important you know what is going on inside collectd. The following diagram shows how values are passed from the read-plugins to the write-plugins:

    +---------------+
    !  Read-Plugin  !
    +-------+-------+
            !
  + - - - - V - - - - +
  : +---------------+ :
  : !   Pre-Cache   ! :
  : !     Chain     ! :
  : +-------+-------+ :
  :         !         :
  :         V         :
  : +-------+-------+ :  +---------------+
  : !     Cache     !--->!  Value Cache  !
  : !     insert    ! :  +---+---+-------+
  : +-------+-------+ :      !   !
  :         !   ,------------'   !
  :         V   V     :          V
  : +-------+---+---+ :  +-------+-------+
  : !  Post-Cache   +--->! Write-Plugins !
  : !     Chain     ! :  +---------------+
  : +---------------+ :
  :                   :
  :  dispatch values  :
  + - - - - - - - - - +

After the values are passed from the ``read'' plugins to the dispatch functions, the pre-cache chain is run first. The values are added to the internal cache afterwards. The post-cache chain is run after the values have been added to the cache. So why is it such a huge deal if chains are run before or after the values have been added to this cache?

Targets that change the identifier of a value list should be executed before the values are added to the cache, so that the name in the cache matches the name that is used in the ``write'' plugins. The "unixsock" plugin, too, uses this cache to receive a list of all available values. If you change the identifier after the value list has been added to the cache, this may easily lead to confusion, but it's not forbidden of course.

The cache is also used to convert counter values to rates. These rates are, for example, used by the "value" match (see below). If you use the rate stored in the cache before the new value is added, you will use the old, previous rate. Write plugins may use this rate, too, see the "csv" plugin, for example. The "unixsock" plugin uses these rates too, to implement the "GETVAL" command.

Last but not last, the stop target makes a difference: If the pre-cache chain returns the stop condition, the value will not be added to the cache and the post-cache chain will not be run.

Chain Name
Adds a new chain with a certain name. This name can be used to refer to a specific chain, for example to jump to it.

Within the Chain block, there can be Rule blocks and Target blocks.

Rule [Name]
Adds a new rule to the current chain. The name of the rule is optional and currently has no meaning for the daemon.

Within the Rule block, there may be any number of Match blocks and there must be at least one Target block.

Match Name
Adds a match to a Rule block. The name specifies what kind of match should be performed. Available matches depend on the plugins that have been loaded.

The arguments inside the Match block are passed to the plugin implementing the match, so which arguments are valid here depends on the plugin being used. If you do not need any to pass any arguments to a match, you can use the shorter syntax:

  Match "foobar"

Which is equivalent to:

  <Match "foobar">
  </Match>
Target Name
Add a target to a rule or a default target to a chain. The name specifies what kind of target is to be added. Which targets are available depends on the plugins being loaded.

The arguments inside the Target block are passed to the plugin implementing the target, so which arguments are valid here depends on the plugin being used. If you do not need any to pass any arguments to a target, you can use the shorter syntax:

  Target "stop"

This is the same as writing:

  <Target "stop">
  </Target>

Built-in targets

The following targets are built into the core daemon and therefore need no plugins to be loaded:
return
Signals the ``return'' condition, see the ``Flow control'' section above. This causes the current chain to stop processing the value and returns control to the calling chain. The calling chain will continue processing targets and rules just after the jump target (see below). This is very similar to the RETURN target of iptables, see iptables(8).

This target does not have any options.

Example:

  Target "return"
stop
Signals the ``stop'' condition, see the ``Flow control'' section above. This causes processing of the value to be aborted immediately. This is similar to the DROP target of iptables, see iptables(8).

This target does not have any options.

Example:

  Target "stop"
write
Sends the value to ``write'' plugins.

Available options:

Plugin Name
Name of the write plugin to which the data should be sent. This option may be given multiple times to send the data to more than one write plugin.

If no plugin is explicitly specified, the values will be sent to all available write plugins.
Example:
  <Target "write">
    Plugin "rrdtool"
  </Target>
jump
Starts processing the rules of another chain, see ``Flow control'' above. If the end of that chain is reached, or a stop condition is encountered, processing will continue right after the jump target, i. e. with the next target or the next rule. This is similar to the -j command line option of iptables, see iptables(8).

Available options:

Chain Name
Jumps to the chain Name. This argument is required and may appear only once.

Example:
  <Target "jump">
    Chain "foobar"
  </Target>

Available matches

regex
Matches a value using regular expressions.

Available options:

Host Regex
Plugin Regex
PluginInstance Regex
Type Regex
TypeInstance Regex
Match values where the given regular expressions match the various fields of the identifier of a value. If multiple regular expressions are given, all regexen must match for a value to match.

Example:
  <Match "regex">
    Host "customer[0-9]+"
    Plugin "^foobar$"
  </Match>
timediff
Matches values that have a time which differs from the time on the server.

This match is mainly intended for servers that receive values over the "network" plugin and write them to disk using the "rrdtool" plugin. RRDtool is very sensitive to the timestamp used when updating the RRD files. In particular, the time must be ever increasing. If a misbehaving client sends one packet with a timestamp far in the future, all further packets with a correct time will be ignored because of that one packet. What's worse, such corrupted RRD files are hard to fix.

This match lets one match all values outside a specified time range (relative to the server's time), so you can use the stop target (see below) to ignore the value, for example.

Available options:

Future Seconds
Matches all values that are ahead of the server's time by Seconds or more seconds. Set to zero for no limit. Either Future or Past must be non-zero.
Past Seconds
Matches all values that are behind of the server's time by Seconds or more seconds. Set to zero for no limit. Either Future or Past must be non-zero.

Example:
  <Match "timediff">
    Future  300
    Past   3600
  </Match>

This example matches all values that are five minutes or more ahead of the server or one hour (or more) lagging behind.

value
Matches the actual value of data sources against given minimum / maximum values. If a data-set consists of more than one data-source, all data-sources must match the specified ranges for a positive match.

Available options:

Min Value
Sets the smallest value which still results in a match. If unset, behaves like negative infinity.
Max Value
Sets the largest value which still results in a match. If unset, behaves like positive infinity.
Invert true|false
Inverts the selection. If the Min and Max settings result in a match, no-match is returned and vice versa. Please note that the Invert setting only effects how Min and Max are applied to a specific value. Especially the DataSource and Satisfy settings (see below) are not inverted.
DataSource DSName [DSName ...]
Select one or more of the data sources. If no data source is configured, all data sources will be checked. If the type handled by the match does not have a data source of the specified name(s), this will always result in no match (independent of the Invert setting).
Satisfy Any|All
Specifies how checking with several data sources is performed. If set to Any, the match succeeds if one of the data sources is in the configured range. If set to All the match only succeeds if all data sources are within the configured range. Default is All.

Usually All is used for positive matches, Any is used for negative matches. This means that with All you usually check that all values are in a ``good'' range, while with Any you check if any value is within a ``bad'' range (or outside the ``good'' range).


Either Min or Max, but not both, may be unset.
Example:
  # Match all values smaller than or equal to 100. Matches only if all data
  # sources are below 100.
  <Match "value">
    Max 100
    Satisfy "All"
  </Match>
  
  # Match if the value of any data source is outside the range of 0 - 100.
  <Match "value">
    Min   0
    Max 100
    Invert true
    Satisfy "Any"
  </Match>
empty_counter
Matches all values with one or more data sources of type COUNTER and where all counter values are zero. These counters usually never increased since they started existing (and are therefore uninteresting), or got reset recently or overflowed and you had really, really bad luck.

Please keep in mind that ignoring such counters can result in confusing behavior: Counters which hardly ever increase will be zero for long periods of time. If the counter is reset for some reason (machine or service restarted, usually), the graph will be empty (NAN) for a long time. People may not understand why.

hashed
Calculates a hash value of the host name and matches values according to that hash value. This makes it possible to divide all hosts into groups and match only values that are in a specific group. The intended use is in load balancing, where you want to handle only part of all data and leave the rest for other servers.

The hashing function used tries to distribute the hosts evenly. First, it calculates a 32 bit hash value using the characters of the hostname:

   hash_value = 0;
   for (i = 0; host[i] != 0; i++)
     hash_value = (hash_value * 251) + host[i];

The constant 251 is a prime number which is supposed to make this hash value more random. The code then checks the group for this host according to the Total and Match arguments:

   if ((hash_value % Total) == Match)
     matches;
   else
     does not match;

Please note that when you set Total to two (i. e. you have only two groups), then the least significant bit of the hash value will be the XOR of all least significant bits in the host name. One consequence is that when you have two hosts, ``server0.example.com'' and ``server1.example.com'', where the host name differs in one digit only and the digits differ by one, those hosts will never end up in the same group.

Available options:

Match Match Total
Divide the data into Total groups and match all hosts in group Match as described above. The groups are numbered from zero, i. e. Match must be smaller than Total. Total must be at least one, although only values greater than one really do make any sense.

You can repeat this option to match multiple groups, for example:

   Match 3 7
   Match 5 7

The above config will divide the data into seven groups and match groups three and five. One use would be to keep every value on two hosts so that if one fails the missing data can later be reconstructed from the second host.


Example:
  # Operate on the pre-cache chain, so that ignored values are not even in the
  # global cache.
  <Chain "PreCache">
    <Rule>
      <Match "hashed">
        # Divide all received hosts in seven groups and accept all hosts in
        # group three.
        Match 3 7
      </Match>
      # If matched: Return and continue.
      Target "return"
    </Rule>
    # If not matched: Return and stop.
    Target "stop"
  </Chain>

Available targets

notification
Creates and dispatches a notification.

Available options:

Message String
This required option sets the message of the notification. The following placeholders will be replaced by an appropriate value:
%{host}
%{plugin}
%{plugin_instance}
%{type}
%{type_instance}
These placeholders are replaced by the identifier field of the same name.
%{ds:name}
These placeholders are replaced by a (hopefully) human readable representation of the current rate of this data source. If you changed the instance name (using the set or replace targets, see below), it may not be possible to convert counter values to rates.

Please note that these placeholders are case sensitive!
Severity FATAL|WARNING|OKAY
Sets the severity of the message. If omitted, the severity ``WARNING'' is used.

Example:
   <Target "notification">
     Message "Oops, the %{type_instance} temperature is currently %{ds:value}!"
     Severity "WARNING"
   </Target>
replace
Replaces parts of the identifier using regular expressions.

Available options:

Host Regex Replacement
Plugin Regex Replacement
PluginInstance Regex Replacement
TypeInstance Regex Replacement
Match the appropriate field with the given regular expression Regex. If the regular expression matches, that part that matches is replaced with Replacement. If multiple places of the input buffer match a given regular expression, only the first occurrence will be replaced.

You can specify each option multiple times to use multiple regular expressions one after another.


Example:
  <Target "replace">
    # Replace "example.net" with "example.com"
    Host "\\<example.net\\>" "example.com"
  
    # Strip "www." from hostnames
    Host "\\<www\\." ""
  </Target>
set
Sets part of the identifier of a value to a given string.

Available options:

Host String
Plugin String
PluginInstance String
TypeInstance String
Set the appropriate field to the given string. The strings for plugin instance and type instance may be empty, the strings for host and plugin may not be empty. It's currently not possible to set the type of a value this way.

Example:
  <Target "set">
    PluginInstance "coretemp"
    TypeInstance "core3"
  </Target>

Backwards compatibility

If you use collectd with an old configuration, i. e. one without a Chain block, it will behave as it used to. This is equivalent to the following configuration: 
  <Chain "PostCache">
    Target "write"
  </Chain>

If you specify a PostCacheChain, the write target will not be added anywhere and you will have to make sure that it is called where appropriate. We suggest to add the above snippet as default target to your ``PostCache'' chain.

Examples

Ignore all values, where the hostname does not contain a dot, i. e. can't be an FQDN. 
  <Chain "PreCache">
    <Rule "no_fqdn">
      <Match "regex">
        Host "^[^\.]*$"
      </Match>
      Target "stop"
    </Rule>
    Target "write"
  </Chain>

SEE ALSO

collectd(1), collectd-exec(5), collectd-perl(5), collectd-unixsock(5), types.db(5), hddtemp(8), iptables(8), kstat(3KSTAT), mbmon(1), psql(1), regex(7), rrdtool(1), sensors(1)

AUTHOR

Florian Forster <octo@verplant.org>