ignored. Values are either string, enclosed in double-quotes,
(floating-point-)numbers or a boolean expression, i.E<nbsp>e. either B<true> or
B<false>. String containing of only alphanumeric characters and underscores do
-not need to be quoted.
+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<nbsp>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 C<LoadPlugin> option B<must> occur
+B<before> the C<E<lt>Plugin ...E<gt>> block.
=head1 GLOBAL OPTIONS
Loads the plugin I<Plugin>. There must be at least one such line or B<collectd>
will be mostly useless.
-=item B<Include> I<File>
+=item B<Include> I<Path>
-Includes the file I<File> as if it was copy and pasted here. To prevent loops
-and shooting yourself in the foot in interesting ways the nesting is limited to
-a depth of 8E<nbsp>levels, which should be sufficient for most uses.
+If I<Path> points to a file, includes that file. If I<Path> points to a
+directory, recursively includes all files within that directory and its
+subdirectories. If the C<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 B<Include> option, the files
+will be included in lexicographical order (as defined by the C<strcmp>
+function). Thus, you can e.E<nbsp>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 8E<nbsp>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 C<E<lt>Plugin fooE<gt>> in more than one
file, but you cannot include files from within blocks.
Path to the plugins (shared objects) of collectd.
-=item B<TypesDB> I<File>
+=item B<TypesDB> I<File> [I<File> ...]
-Set the file that contains the data-set descriptions.
+Set one or more files that contain the data-set descriptions. See
+L<types.db(5)> for a description of the format of this file.
=item B<Interval> I<Seconds>
Configures the interval in which to query the read plugins. Obviously smaller
-values lead to a higher system load produces by collectd, while higher values
+values lead to a higher system load produced by collectd, while higher values
lead to more coarse statistics.
=item B<ReadThreads> I<Num>
-Number of threads to start for reading plugins. The default value if B<5>, but
+Number of threads to start for reading plugins. The default value is B<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.
+=item B<Hostname> I<Name>
+
+Sets the hostname that identifies a host. If you omit this setting, the
+hostname will be determinded using the L<gethostname(2)> system call.
+
+=item B<FQDNLookup> B<true|false>
+
+If B<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 C<gethostname>.
+
+Using this feature (i.E<nbsp>e. setting this option to B<true>) is recommended.
+However, to preserve backwards compatibility the default is set to B<false>.
+The sample config file that is installed with C<makeE<nbsp>install> includes a
+line which sets this option, though, so that default installations will have
+this setting enabled.
+
+=item B<PreCacheChain> I<ChainName>
+
+=item B<PostCacheChain> I<ChainName>
+
+Configure the name of the "pre-cache chain" and the "post-cache chain". Please
+see L<FILTER CONFIGURATION> below on information on chains and how these
+setting change the daemon's behavior.
+
=back
=head1 PLUGIN OPTIONS
Optional password needed for authentication.
+=item B<VerifyPeer> B<true|false>
+
+Enable or disable peer SSL certificate verification. See
+L<http://curl.haxx.se/docs/sslcerts.html> for details. Enabled by default.
+
+=item B<VerifyHost> B<true|false>
+
+Enable or disable peer host name verification. If enabled, the plugin checks
+if the C<Common Name> or a C<Subject Alternate Name> field of the SSL
+certificate matches the host name provided by the B<URL> option. If this
+identity check fails, the connection is aborted. Obviously, only works when
+connecting to a SSL enabled server. Enabled by default.
+
=item B<CACert> I<File>
File that holds one or more SSL certificates. If you want to use HTTPS you will
=back
+=head2 Plugin C<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 C<libcurl> and parses it using C<libxml2>.
+
+The configuration options are the same as for the C<apache> plugin above:
+
+=over 4
+
+=item B<URL> I<http://localhost/ascent/status/>
+
+Sets the URL of the XML status output.
+
+=item B<User> I<Username>
+
+Optional user name needed for authentication.
+
+=item B<Password> I<Password>
+
+Optional password needed for authentication.
+
+=item B<VerifyPeer> B<true|false>
+
+Enable or disable peer SSL certificate verification. See
+L<http://curl.haxx.se/docs/sslcerts.html> for details. Enabled by default.
+
+=item B<VerifyHost> B<true|false>
+
+Enable or disable peer host name verification. If enabled, the plugin checks
+if the C<Common Name> or a C<Subject Alternate Name> field of the SSL
+certificate matches the host name provided by the B<URL> option. If this
+identity check fails, the connection is aborted. Obviously, only works when
+connecting to a SSL enabled server. Enabled by default.
+
+=item B<CACert> I<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 C<libcurl>
+and are checked by default depends on the distribution you use.
+
+=back
+
+=head2 Plugin C<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 C<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:
+
+=over 4
+
+=item B<URL> I<URL>
+
+URL from which to retrieve the XML data. If not specified,
+C<http://localhost:8053/> will be used.
+
+=item B<OpCodes> I<true>|I<false>
+
+When enabled, statistics about the I<"OpCodes">, for example the number of
+C<QUERY> packets, are collected.
+
+Default: Enabled.
+
+=item B<QTypes> I<true>|I<false>
+
+When enabled, the number of I<incoming> queries by query types (for example
+C<A>, C<MX>, C<AAAA>) is collected.
+
+Default: Enabled.
+
+=item B<ServerStats> I<true>|I<false>
+
+Collect global server statistics, such as requests received over IPv4 and IPv6,
+successful queries, and failed updates.
+
+Default: Enabled.
+
+=item B<ZoneMaintStats> I<true>|I<false>
+
+Collect zone maintenance statistics, mostly information about notifications
+(zone updates) and zone transfers.
+
+Default: Enabled.
+
+=item B<ResolverStats> I<true>|I<false>
+
+Collect resolver statistics, i.E<nbsp>e. statistics about outgoing requests
+(e.E<nbsp>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 B<ResolverStats> option within a B<View "_default"> block
+instead for the same functionality.
+
+Default: Disabled.
+
+=item B<MemoryStats>
+
+Collect global memory statistics.
+
+Default: Enabled.
+
+=item B<View> I<Name>
+
+Collect statistics about a specific I<"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 C<_default> view.
+
+Within a E<lt>B<View>E<nbsp>I<name>E<gt> block, you can specify which
+information you want to collect about a view. If no B<View> block is
+configured, no detailed view statistics will be collected.
+
+=over 4
+
+=item B<QTypes> I<true>|I<false>
+
+If enabled, the number of I<outgoing> queries by query type (e.E<nbsp>g. C<A>,
+C<MX>) is collected.
+
+Default: Enabled.
+
+=item B<ResolverStats> I<true>|I<false>
+
+Collect resolver statistics, i.E<nbsp>e. statistics about outgoing requests
+(e.E<nbsp>g. queries over IPv4, lame servers).
+
+Default: Enabled.
+
+=item B<CacheRRSets> I<true>|I<false>
+
+If enabled, the number of entries (I<"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.E<nbsp>g. "!A".
+
+Default: Enabled.
+
+=item B<Zone> I<Name>
+
+When given, collect detailed information about the given zone in the view. The
+information collected if very similar to the global B<ServerStats> information
+(see above).
+
+You can repeat this option to collect detailed information about multiple
+zones.
+
+By default no detailed zone information is collected.
+
+=back
+
+=back
+
=head2 Plugin C<cpufreq>
This plugin doesn't have any options. It reads
Set the directory to store CSV-files under. Per default CSV-files are generated
beneath the daemon's working directory, i.E<nbsp>e. the B<BaseDir>.
+The special strings B<stdout> and B<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.
+
+=item B<StoreRates> B<true|false>
+
+If set to B<true>, convert counter values to rates. If set to B<false> (the
+default) counter values are stored as is, i.E<nbsp>e. as an increasing integer
+number.
+
+=back
+
+=head2 Plugin C<curl>
+
+The curl plugin uses the B<libcurl> (L<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 B<Plugin> block, there may be one or more B<Page> blocks, each defining
+a web page and one or more "matches" to be performed on the returned data. The
+string argument to the B<Page> block is used as plugin instance.
+
+The following options are valid within B<Page> blocks:
+
+=over 4
+
+=item B<URL> I<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 ;)
+
+=item B<User> I<Name>
+
+Username to use if authorization is required to read the page.
+
+=item B<Password> I<Password>
+
+Password to use if authorization is required to read the page.
+
+=item B<VerifyPeer> B<true>|B<false>
+
+Enable or disable peer SSL certificate verification. See
+L<http://curl.haxx.se/docs/sslcerts.html> for details. Enabled by default.
+
+=item B<VerifyHost> B<true>|B<false>
+
+Enable or disable peer host name verification. If enabled, the plugin checks if
+the C<Common Name> or a C<Subject Alternate Name> field of the SSL certificate
+matches the host name provided by the B<URL> option. If this identity check
+fails, the connection is aborted. Obviously, only works when connecting to a
+SSL enabled server. Enabled by default.
+
+=item B<CACert> I<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 C<libcurl>
+and are checked by default depends on the distribution you use.
+
+=item B<E<lt>MatchE<gt>>
+
+One or more B<Match> blocks that define how to match information in the data
+returned by C<libcurl>. The C<curl> plugin uses the same infrastructure that's
+used by the C<tail> plugin, so please see the documentation of the C<tail>
+plugin below on how matches are defined.
+
+=back
+
+=head2 Plugin C<dbi>
+
+This plugin uses the B<dbi> library (L<http://libdbi.sourceforge.net/>) to
+connect to various databases, execute I<SQL> statements and read back the
+results. I<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 B<Query> option I<within> the
+B<E<lt>DatabaseE<gt>> block. You can have any number of queries and databases
+and you can also use the B<Include> statement to split up the configuration
+file in multiple, smaller files. However, the B<E<lt>QueryE<gt>> block I<must>
+precede the B<E<lt>DatabaseE<gt>> blocks, because the file is interpreted from
+top to bottom!
+
+The following is a complete list of options:
+
+=head3 B<Query> blocks
+
+Query blocks define I<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 B<Query> block, there is one or more B<Result> blocks. B<Result> blocks
+define which column holds which value or instance information. You can use
+multiple B<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:
+
+=over 4
+
+=item B<Statement> I<SQL>
+
+Sets the statement that should be executed on the server. This is B<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.)
+
+=item B<MinVersion> I<Version>
+
+=item B<MaxVersion> I<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 C<dbi_conn_get_engine_version>, see the
+L<libdbi documentation|http://libdbi.sourceforge.net/docs/programmers-guide/reference-conn.html#DBI-CONN-GET-ENGINE-VERSION>
+for details. Basically, each part of the version is assumed to be in the range
+from B<00> to B<99> and all dots are removed. So version "4.1.2" becomes
+"40102", version "5.0.42" becomes "50042".
+
+B<Warning:> The plugin will use B<all> matching queries, so if you specify
+multiple queries with the same name and B<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.
+
+=item B<Type> I<Type>
+
+The B<type> that's used for each line returned. See L<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 B<ValuesFrom>
+setting below.
+
+There must be exactly one B<Type> option inside each B<Result> block.
+
+=item B<InstancePrefix> I<prefix>
+
+Prepends I<prefix> to the type instance. If B<InstancesFrom> (see below) is not
+given, the string is simply copied. If B<InstancesFrom> is given, I<prefix> and
+all strings returned in the appropriate columns are concatenated together,
+separated by dashes I<("-")>.
+
+=item B<InstancesFrom> I<column0> [I<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 I<("-")> 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 B<InstancesFrom>: B<You> have to make
+sure that only one row is returned in this case.
+
+If neither B<InstancePrefix> nor B<InstancesFrom> is given, the type-instance
+will be empty.
+
+=item B<ValuesFrom> I<column0> [I<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 B<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 B<ValuesFrom> option inside each B<Result> block.
+
+=back
+
+=head3 B<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
+documentationE<nbsp>- 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.
+
+=over 4
+
+=item B<Driver> I<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",
+B<D>ataB<B>ase B<D>river, and some distributions ship them in separate
+packages. Drivers for the "dbi" library are developed by the B<libdbi-drivers>
+project at L<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.
+
+=item B<DriverOption> I<Key> I<Value>
+
+Sets driver-specific options. What option a driver supports can be found in the
+documentation for each driver, somewhere at
+L<http://libdbi-drivers.sourceforge.net/>. However, the options "host",
+"username", "password", and "dbname" seem to be deE<nbsp>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 libraryE<nbsp>/
+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.
+
+=item B<SelectDB> I<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.
+
+=item B<Query> I<QueryName>
+
+Associates the query named I<QueryName> with this database connection. The
+query needs to be defined I<before> this statement, i.E<nbsp>e. all query
+blocks you want to refer to must be placed above the database block you want to
+refer to them from.
=back
=back
+=head2 Plugin C<disk>
+
+The C<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.
+
+=over 4
+
+=item B<Disk> I<Name>
+
+Select the disk I<Name>. Whether it is collected or ignored depends on the
+B<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]/"
+
+=item B<IgnoreSelected> B<true>|B<false>
+
+Sets whether selected disks, i.E<nbsp>e. the ones matches by any of the B<Disk>
+statements, are ignored or if all other disks are ignored. The behavior
+(hopefully) is intuitive: If no B<Disk> option is configured, all disks are
+collected. If at least one B<Disk> option is given and no B<IgnoreSelected> or
+set to B<false>, B<only> matching disks will be collected. If B<IgnoreSelected>
+is set to B<true>, all disks are collected B<except> the ones matched.
+
+=back
+
=head2 Plugin C<dns>
=over 4
=item B<SocketGroup> I<Group>
-If running as root change the group of the UNIX-socket after it has been
+If running as root change the group of the UNIX-socket after it has been
created. Defaults to B<collectd>.
=item B<SocketPerms> I<Permissions>
=over 4
-=item B<Exec> I<User>[:[I<Group>]] I<Executable>
+=item B<Exec> I<User>[:[I<Group>]] I<Executable> [I<E<lt>argE<gt>> [I<E<lt>argE<gt>> ...]]
+
+=item B<NotificationExec> I<User>[:[I<Group>]] I<Executable> [I<E<lt>argE<gt>> [I<E<lt>argE<gt>> ...]]
Execute the executable I<Executable> as user I<User>. If the user name is
followed by a colon and a group name, the effective group is set to that group.
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 B<Exec> and B<NotificationExec> statements change the semantics of the
+programs executed, i.E<nbsp>e. the data passed to them and the response
+expected from them. This is documented in great detail in L<collectd-exec(5)>.
+
+=back
+
+=head2 Plugin C<filecount>
+
+The C<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 C<Directory> blocks,
+each of which specifies a directory in which to count the files. Within those
+blocks, the following options are recognized:
+
+=over 4
+
+=item B<Instance> I<Instance>
+
+Sets the plugin instance to I<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.
+
+=item B<Name> I<Pattern>
+
+Only count files that match I<Pattern>, where I<Pattern> is a shell-like
+wildcard as understood by L<fnmatch(3)>. Only the B<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 B<-name> parameter to L<find(1)>.
+
+=item B<MTime> I<Age>
+
+Count only files of a specific age: If I<Age> is greater than zero, only files
+that haven't been touched in the last I<Age> seconds are counted. If I<Age> is
+a negative number, this is inversed. For example, if B<-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<nbsp>e.
+must be passed as string. So the B<-60> could also be written as B<"-1m"> (one
+minute). Valid multipliers are C<s> (second), C<m> (minute), C<h> (hour), C<d>
+(day), C<w> (week), and C<y> (year). There is no "month" multiplier. You can
+also specify fractional numbers, e.E<nbsp>g. B<"0.5d"> is identical to
+B<"12h">.
+
+=item B<Size> I<Size>
+
+Count only files of a specific size. When I<Size> is a positive number, only
+files that are at least this big are counted. If I<Size> is a negative number,
+this is inversed, i.E<nbsp>e. only files smaller than the absolute value of
+I<Size> are counted.
+
+As with the B<MTime> option, a "multiplier" may be added. For a detailed
+description see above. Valid multipliers here are C<b> (byte), C<k> (kilobyte),
+C<m> (megabyte), C<g> (gigabyte), C<t> (terabyte), and C<p> (petabyte). Please
+note that there are 1000 bytes in a kilobyte, not 1024.
+
+=item B<Recursive> I<true>|I<false>
+
+Controls whether or not to recurse into subdirectories. Enabled by default.
+
=back
=head2 Plugin C<hddtemp>
TCP-Port to connect to. Defaults to B<7634>.
+=item B<TranslateDevicename> I<true>|I<false>
+
+If enabled, translate the disk names to major/minor device numbers
+(e.E<nbsp>g. "8-0" for /dev/sda). For backwards compatibility this defaults to
+I<true> but it's recommended to disable it as it will probably be removed in
+the next major version.
+
=back
=head2 Plugin C<interface>
interfaces you're interested in. Sometimes, however, it's easier/preferred
to collect all interfaces I<except> a few ones. This option enables you to
do that: By setting B<IgnoreSelected> to I<true> the effect of
-B<Interface> is inversed: All selected interfaces are ignored and all
+B<Interface> is inverted: All selected interfaces are ignored and all
other interfaces are collected.
=back
+=head2 Plugin C<ipmi>
+
+=over 4
+
+=item B<Sensor> I<Sensor>
+
+Selects sensors to collect or to ignore, depending on B<IgnoreSelected>.
+
+=item B<IgnoreSelected> I<true>|I<false>
+
+If no configuration if given, the B<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 B<IgnoreSelected> to I<true>
+the effect of B<Sensor> is inverted: All selected sensors are ignored and
+all other sensors are collected.
+
+=item B<NotifySensorAdd> I<true>|I<false>
+
+If a sensor appears after initialization time of a minute a notification
+is sent.
+
+=item B<NotifySensorRemove> I<true>|I<false>
+
+If a sensor disappears a notification is sent.
+
+=item B<NotifySensorNotPresent> I<true>|I<false>
+
+If you have for example dual power supply and one of them is (un)plugged then
+a notification is sent.
+
+=back
+
=head2 Plugin C<iptables>
=over 4
can use the B<Irq>-option to pick the interrupt you're interested in.
Sometimes, however, it's easier/preferred to collect all interrupts I<except> a
few ones. This option enables you to do that: By setting B<IgnoreSelected> to
-I<true> the effect of B<Irq> is inversed: All selected interrupts are ignored
+I<true> the effect of B<Irq> is inverted: All selected interrupts are ignored
and all other interrupts are collected.
=back
-=head2 Plugin C<libvirtstats>
+=head2 Plugin C<java>
+
+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 config options:
+
+=over 4
+
+=item B<JVMArg> I<Argument>
+
+Argument that is to be passed to the I<Java Virtual Machine> (JVM). This works
+exactly the way the arguments to the I<java> binary on the command line work.
+Execute C<javaE<nbsp>--help> for details.
+
+=item B<LoadPlugin> I<JavaClass>
+
+Instantiates a new I<JavaClass> object. The following methods of this class are
+used when available:
+
+=over 4
+
+=item *
+
+public int B<Config> (org.collectd.api.OConfigItem ci)
+
+=item *
+
+public int B<Init> ()
+
+=item *
+
+public int B<Read> ()
+
+=item *
+
+public int B<Write> (org.collectd.protocol.ValueList vl)
+
+=item *
+
+public int B<Shutdown> ()
+
+=back
+
+=item B<Plugin> I<JavaClass>
+
+The entrie block is passed to the Java plugin as an
+I<org.collectd.api.OConfigItem> object.
+
+=back
+
+=head2 Plugin C<libvirt>
-This plugin allows CPU, disk and network load to be monitored for
-virtualized guests on the machine. The statistics are collected
-through libvirt (L<http://libvirt.org/>).
+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
+(L<http://libvirt.org/>).
Only I<Connection> is required.
=item B<Connection> I<uri>
-Connect to the hypervisor given by I<uri>. For example if using
-Xen use:
+Connect to the hypervisor given by I<uri>. For example if using Xen use:
Connection "xen:///"
-Details are URIs allowed are given at L<http://libvirt.org/uri.html>.
+Details which URIs allowed are given at L<http://libvirt.org/uri.html>.
=item B<RefreshInterval> I<seconds>
-Refresh the list of domains and devices every I<seconds>. The default
-is 60 seconds. Setting this to be the same or smaller than the
-I<Interval> will cause the list of domains and devices to be refreshed
-on every iteration.
+Refresh the list of domains and devices every I<seconds>. The default is 60
+seconds. Setting this to be the same or smaller than the I<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.
+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.
=item B<Domain> I<name>
=item B<IgnoreSelected> I<true>|I<false>
-Select which domains and devices are monitored.
+Select which domains and devices are collected.
-If I<IgnoreSelected> is not given or I<false> then only the
-listed domains and disk/network devices are monitored.
+If I<IgnoreSelected> is not given or I<false> then only the listed domains and
+disk/network devices are collected.
-If I<IgnoreSelected> is I<true> then the test is reversed
-and the listed domains and disk/network devices are ignored,
-while the rest are monitored.
+If I<IgnoreSelected> is I<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 I</.../> and collectd was compiled with support
-for regexps.
+The domain name and device names may use a regular expression, if the name is
+surrounded by I</.../> and collectd was compiled with support for regexps.
-The default is to monitor all domains and all their devices.
+The default is to collect statistics for all domains and all their devices.
Example:
BlockDevice "/:hdb/"
IgnoreSelected "true"
-Ignore all I<hdb> devices on any domain, but other block devices
-(eg. I<hda>) will be monitored.
-
-=item B<HostnameFormat> I<name|uuid|hostname|...>
+Ignore all I<hdb> devices on any domain, but other block devices (eg. I<hda>)
+will be collected.
-When libvirtstats logs data, it sets the collectd I<host> field in the
-data according to this setting.
+=item B<HostnameFormat> B<name|uuid|hostname|...>
-The default is I<name> which means to use the guest name from the
-hypervisor.
+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 B<name>.
-I<uuid> means use the guest's UUID. This is useful if you want to
-track the same guest across migrations.
+B<uuid> means use the guest's UUID. This is useful if you want to track the
+same guest across migrations.
-I<hostname> means to use the global I<Hostname> setting, which is
-probably not useful on its own because all guests will appear to have
-the same name.
+B<hostname> means to use the global B<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
-I<name uuid>
-means to concatenate the guest name and UUID (with a literal
-colon character between, thus I<"foo:1234-1234-1234-1234">).
+You can also specify combinations of these fields. For example B<name uuid>
+means to concatenate the guest name and UUID (with a literal colon character
+between, thus I<"foo:1234-1234-1234-1234">).
=back
Sets the log-level. If, for example, set to B<notice>, then all events with
severity B<notice>, B<warning>, or B<err> will be written to the logfile.
+Please note that B<debug> is only available if collectd has been compiled with
+debugging support.
+
=item B<File> I<File>
Sets the file to write log messages to. The special strings B<stdout> and
=back
+B<Note>: There is no need to notify the daemon after moving or removing the
+log file (e.E<nbsp>g. when rotating the logs). The plugin reopens the file
+for each line it writes.
+
=head2 Plugin C<mbmon>
The C<mbmon plugin> uses mbmon to retrieve temperature, voltage, etc.
-Be default collectd connects to B<localhost> (127.0.0.1), port B<411/tcp>. The
+Be default collectd connects to B<localhost> (127.0.0.1), port B<411/tcp>. The
B<Host> and B<Port> options can be used to change these values, see below.
C<mbmon> has to be running to work correctly. If C<mbmon> is not running
timeouts may appear which may interfere with other statistics..
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 C<SHOW STATUS> and evaluates C<Bytes_{received,sent}>,
-C<Com_*> and C<Handler_*> which correspond to F<mysql_octets.rrd>,
-F<mysql_commands-*.rrd> and F<mysql_handler-*.rrd>. Also, the values of
-C<Qcache_*> are put in F<mysql_qcache.rrd> and values of C<Threads_*> are put
-in F<mysql_threads.rrd>. Please refer to the B<MySQL reference manual>,
-I<5.2.4. Server Status Variables> for an explanation of these values.
+This plugin issues the MySQL C<SHOW STATUS> command and collects information
+about MySQL network traffic, executed statements, requests, the query cache
+and threads by evaluating the C<Bytes_{received,sent}>, C<Com_*>,
+C<Handler_*>, C<Qcache_*> and C<Threads_*> return values. Please refer to the
+B<MySQL reference manual>, I<5.1.6. Server Status Variables> for an
+explanation of these values.
Use the following options to configure the plugin:
=item B<User> I<Username>
-Username to use when connecting to the database.
+Username to use when connecting to the database. The user does not have to be
+granted any privileges (which is synonym to granting the C<USAGE> privilege).
+Any existing MySQL user will do.
=item B<Password> I<Password>
Select this database. Defaults to I<no database> which is a perfectly reasonable
option for what this plugin does.
+=item B<Port> I<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 B<Host> is set to B<localhost> (the default), this setting has no effect.
+See the documentation for the C<mysql_real_connect> function for details.
+
+=item B<Socket> I<Socket>
+
+Specifies the path to the UNIX domain socket of the MySQL server. This option
+only has any effect, if B<Host> is set to B<localhost> (the default).
+Otherwise, use the B<Port> option above. See the documentation for the
+C<mysql_real_connect> function for details.
+
=back
=head2 Plugin C<netlink>
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
+ids by their name. So, for example, a qdisc may be identified by
C<pfifo_fast-1:0> even though the minor number of B<all> qdiscs is zero and
thus not displayed by tc(1).
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
-B<IgnoreSelected> to B<true>, this behavior is inversed, i.E<nbsp>e. the
+B<IgnoreSelected> to B<true>, this behavior is inverted, i.E<nbsp>e. the
specified statistics will not be collected.
=back
Optional password needed for authentication.
+=item B<VerifyPeer> B<true|false>
+
+Enable or disable peer SSL certificate verification. See
+L<http://curl.haxx.se/docs/sslcerts.html> for details. Enabled by default.
+
+=item B<VerifyHost> B<true|false>
+
+Enable or disable peer host name verification. If enabled, the plugin checks
+if the C<Common Name> or a C<Subject Alternate Name> field of the SSL
+certificate matches the host name provided by the B<URL> option. If this
+identity check fails, the connection is aborted. Obviously, only works when
+connecting to a SSL enabled server. Enabled by default.
+
=item B<CACert> I<File>
File that holds one or more SSL certificates. If you want to use HTTPS you will
=back
+=head2 Plugin C<notify_desktop>
+
+This plugin sends a desktop notification to a notification daemon, as defined
+in the Desktop Notification Specification. To actually display the
+notifications, B<notification-daemon> is required and B<collectd> has to be
+able to access the X server.
+
+The Desktop Notification Specification can be found at
+L<http://www.galago-project.org/specs/notification/>.
+
+=over 4
+
+=item B<OkayTimeout> I<timeout>
+
+=item B<WarningTimeout> I<timeout>
+
+=item B<FailureTimeout> I<timeout>
+
+Set the I<timeout>, in milliseconds, after which to expire the notification
+for C<OKAY>, C<WARNING> and C<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.
+
+=back
+
+=head2 Plugin C<notify_email>
+
+The I<notify_email> plugin uses the I<ESMTP> library to send notifications to a
+configured email address.
+
+I<libESMTP> is available from L<http://www.stafford.uklinux.net/libesmtp/>.
+
+Available configuration options:
+
+=over 4
+
+=item B<From> I<Address>
+
+Email address from which the emails should appear to come from.
+
+Default: C<root@localhost>
+
+=item B<Recipient> I<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 B<Recipient> must be present for the plugin to work correctly.
+
+=item B<SMTPServer> I<Hostname>
+
+Hostname of the SMTP server to connect to.
+
+Default: C<localhost>
+
+=item B<SMTPPort> I<Port>
+
+TCP port to connect to.
+
+Default: C<25>
+
+=item B<SMTPUser> I<Username>
+
+Username for ASMTP authentication. Optional.
+
+=item B<SMTPPassword> I<Password>
+
+Password for ASMTP authentication. Optional.
+
+=item B<Subject> I<Subject>
+
+Subject-template to use when sending emails. There must be exactly two
+string-placeholders in the subject, given in the standard I<printf(3)> syntax,
+i.E<nbsp>e. C<%s>. The first will be replaced with the severity, the second
+with the hostname.
+
+Default: C<Collectd notify: %s@%s>
+
+=back
+
=head2 Plugin C<ntpd>
=over 4
UDP-Port to connect to. Defaults to B<123>.
+=item B<ReverseLookups> B<true>|B<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.
+
=back
=head2 Plugin C<nut>
=back
+=head2 Plugin C<onewire>
+
+B<EXPERIMENTAL!> See notes below.
+
+The C<onewire> plugin uses the B<owcapi> library from the B<owfs> project
+L<http://owfs.org/> to read sensors connected via the onewire bus.
+
+Currently only temperature sensors (sensors with the family code C<10>,
+e.E<nbsp>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.
+
+=over 4
+
+=item B<Device> I<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
+L<owserver(1)> socket, usually B<localhost:4304>.
+
+Though the documentation claims to automatically recognize the given address
+format, with versionE<nbsp>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 B<required> and does not have a default value.
+
+=item B<Sensor> I<Sensor>
+
+Selects sensors to collect or to ignore, depending on B<IgnoreSelected>, see
+below. Sensors are specified without the family byte at the beginning, to you'd
+use C<F10FCA000800>, and B<not> include the leading C<10.> family byte and
+point.
+
+=item B<IgnoreSelected> I<true>|I<false>
+
+If no configuration if given, the B<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 I<except> a few specified ones. This option
+enables you to do that: By setting B<IgnoreSelected> to I<true> the effect of
+B<Sensor> is inverted: All selected interfaces are ignored and all other
+interfaces are collected.
+
+=back
+
+B<EXPERIMENTAL!> The C<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 I<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. ThanksE<nbsp>:)
+
+=head2 Plugin C<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
+B<--status> option of OpenVPN. Since OpenVPN can write two different formats,
+you need to set the required format, too. This is done by setting
+B<--status-version> to B<2>.
+
+So, in a nutshell you need:
+
+ openvpn $OTHER_OPTIONS \
+ --status "/var/run/openvpn-status" 10 \
+ --status-version 2
+
+Available options:
+
+=over 4
+
+=item B<StatusFile> I<File>
+
+Specifies the location of the status file.
+
+=back
+
+=head2 Plugin C<oracle>
+
+The "oracle" plugin uses the Oracle® Call Interface I<(OCI)> to connect to an
+Oracle® Database and lets you execute SQL statements there. It is very similar
+to the "dbi" plugin, because it was written around the same time. See the "dbi"
+plugin's documentation above for details.
+
+ <Plugin oracle>
+ <Query "out_of_stock">
+ Statement "SELECT category, COUNT(*) AS value FROM products WHERE in_stock = 0 GROUP BY category"
+ <Result>
+ Type "gauge"
+ # InstancePrefix "foo"
+ InstancesFrom "category"
+ ValuesFrom "value"
+ </Result>
+ </Query>
+ <Database "product_information">
+ ConnectID "db01"
+ Username "oracle"
+ Password "secret"
+ Query "out_of_stock"
+ </Database>
+ </Plugin>
+
+=head3 B<Query> blocks
+
+The Query blocks are handled identically to the Query blocks of the "dbi"
+plugin. Please see its documentation above for details on how to specify
+queries.
+
+=head3 B<Database> blocks
+
+Database blocks define a connection to a database and which queries should be
+sent to that database. Each database needs a "name" as string argument in the
+starting tag of the block. This name will be used as "PluginInstance" in the
+values submitted to the daemon. Other than that, that name is not used.
+
+=over 4
+
+=item B<ConnectID> I<ID>
+
+Defines the "database alias" or "service name" to connect to. Usually, these
+names are defined in the file named C<$ORACLE_HOME/network/admin/tnsnames.ora>.
+
+=item B<Username> I<Username>
+
+Username used for authentication.
+
+=item B<Password> I<Password>
+
+Password used for authentication.
+
+=item B<Query> I<QueryName>
+
+Associates the query named I<QueryName> with this database connection. The
+query needs to be defined I<before> this statement, i.E<nbsp>e. all query
+blocks you want to refer to must be placed above the database block you want to
+refer to them from.
+
+=back
+
=head2 Plugin C<perl>
This plugin embeds a Perl-interpreter into collectd and provides an interface
=back
-=head2 Plugin C<processes>
+=head2 Plugin C<postgresql>
+
+The C<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 B<Database> block as described below. The default statistics are
+collected from PostgreSQL's B<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 B<PostgreSQL
+Documentation> for details.
+
+By specifying custom database queries using a B<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 B<PostgreSQL Documentation> manual can be found at
+L<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 B<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
+B<MinPGVersion> and B<MaxPGVersion> options below for an exception to this
+rule). The following configuration options are available to define the query:
+
+In each B<Query> block, there is one or more B<Result> blocks. B<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 B<Result> blocks may be used to extract multiple values from a single
+query.
=over 4
-=item B<Process> I<Name>
+=item B<Statement> I<sql query statement>
-Select more detailed statistics of processes matching this name. The statistics
-collected for these selected processes are size of the resident segment size
-(RSS), user- and system-time used, number of processes and number of threads,
-and minor and major pagefaults.
+Specify the I<sql query statement> which the plugin should execute. The string
+may contain the tokens B<$1>, B<$2>, etc. which are used to reference the
+first, second, etc. parameter. The value of the parameters is specified by the
+B<Param> configuration option - see below for details. To include a literal
+B<$> character followed by a number, surround it with single quotes (B<'>).
-=back
+Any SQL command which may return data (such as C<SELECT> or C<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.
-=head2 Plugin C<rrdtool>
+The returned lines will be handled separately one after another.
-You can use the settings B<StepSize>, B<HeartBeat>, B<RRARows>, and B<XFF> to
-fine-tune your RRD-files. Please read L<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.
+=item B<Query> I<sql query statement>
+
+This is a deprecated synonym for B<Statement>. It will be removed in version 5
+of collectd.
+
+=item B<Param> I<hostname>|I<database>|I<username>|I<interval>
+
+Specify the parameters which should be passed to the SQL query. The parameters
+are referred to in the SQL query as B<$1>, B<$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 B<Param> option as follows:
=over 4
-=item B<DataDir> I<Directory>
+=item I<hostname>
-Set the directory to store RRD-files under. Per default RRD-files are generated
-beneath the daemon's working directory, i.E<nbsp>e. the B<BaseDir>.
+The configured hostname of the database connection. If a UNIX domain socket is
+used, the parameter expands to "localhost".
-=item B<StepSize> I<Seconds>
+=item I<database>
-B<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 C<snmp plugin>, the
-C<exec plugin> or when the daemon is set up to receive data from other hosts.
+The name of the database of the current connection.
-=item B<HeartBeat> I<Seconds>
+=item I<username>
-B<Force> the heartbeat of newly created RRD-files. This setting should be unset
-in which case the heartbeat is set to twice the B<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.
+The username used to connect to the database.
-=item B<RRARows> I<NumRows>
+=item I<interval>
-The C<rrdtool plugin> calculates the number of PDPs per CDP based on the
-B<StepSize>, this setting and a timespan. This plugin creates RRD-files with
-three times five RRAs, i. e. five RRAs with the CFs B<MIN>, B<AVERAGE>, and
-B<MAX>. The five RRAs are optimized for graphs covering one hour, one day, one
-week, one month, and one year.
+The interval collectd is using (as specified by the B<Interval> option).
-So for each timespan, it calculates how many PDPs need to be consolidated into
-one CDP by calculating:
- number of PDPs = timespan / (stepsize * rrarows)
+=back
-Bottom line is, set this no smaller than the width of you graphs in pixels. The
-default is 1200.
+Please note that parameters are only supported by PostgreSQL's protocol
+version 3 and above which was introduced in version 7.4 of PostgreSQL.
-=item B<RRATimespan> I<Seconds>
+=item B<Type> I<type>
-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.
+The I<type> name to be used when dispatching the values. The type describes
+how to handle the data and where to store it. See L<types.db(5)> for more
+details on types and their configuration. The number and type of values (as
+selected by the B<ValuesFrom> option) has to match the type of the given name.
-For more information on how RRA-sizes are calculated see B<RRARows> above.
+This option is required inside a B<Result> block.
-=item B<XFF> I<Factor>
+=item B<InstancePrefix> I<prefix>
-Set the "XFiles Factor". The default is 0.1. If unsure, don't set this option.
+=item B<InstancesFrom> I<column0> [I<column1> ...]
-=item B<CacheFlush> I<Seconds>
+Specify how to create the "TypeInstance" for each data set (i.E<nbsp>e. line).
+B<InstancePrefix> defines a static prefix that will be prepended to all type
+instances. B<InstancesFrom> defines the column names whose values will be used
+to create the type instance. Multiple values will be joined together using the
+hyphen (C<->) as separation character.
-When the C<rrdtool plugin> uses a cache (by setting B<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 B<CacheFlush> is set, then the
-entire cache is searched for entries older than B<CacheTimeout> seconds and
-written to disk every I<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.
+The plugin itself does not check whether or not all built instances are
+different. It is your responsibility to assure that each is unique.
-=item B<CacheTimeout> I<Seconds>
+Both options are optional. If none is specified, the type instance will be
+empty.
-If this option is set to a value greater than zero, the C<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.
+=item B<ValuesFrom> I<column0> [I<column1> ...]
-=back
+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 B<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.
-=head2 Plugin C<sensors>
+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 L<strtoll(3)> and
+L<strtod(3)> functions, so anything supported by those functions is supported
+by the plugin as well.
-The C<sensors plugin> uses B<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 F</etc/sensors.conf>. Read
-L<sensors.conf(5)> for details.
+This option is required inside a B<Result> block and may be specified multiple
+times. If multiple B<ValuesFrom> options are specified, the columns are read
+in the given order.
-The B<lm_sensors> homepage can be found at
-L<http://secure.netroedge.com/~lm78/>.
+=item B<Column> I<type> [I<type instance>]
-=over 4
+This is a deprecated alternative to a B<Result> block. It will be removed in
+version 5 of collectd. It is equivalent to the following B<Result> block:
-=item B<Sensor> I<chip-bus-address/type-feature>
+ <Result>
+ Type I<type>
+ InstancePrefix I<type instance>
+ ValuesFrom I<name of the x. column>
+ </Result>
-Selects the name of the sensor which you want to collect or ignore, depending
-on the B<IgnoreSelected> below. For example, the option "B<Sensor>
-I<it8712-isa-0290/voltage-in1>" will cause collectd to gather data for the
-voltage sensor I<in1> of the I<it8712> on the isa bus at the address 0290.
+The order of the B<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.
-=item B<IgnoreSelected> I<true>|I<false>
+=item B<MinPGVersion> I<version>
-If no configuration if given, the B<sensors>-plugin will collect data from all
-sensors. This may not be practical, especially for uninteresting sensors.
-Thus, you can use the B<Sensor>-option to pick the sensors you're interested
-in. Sometimes, however, it's easier/preferred to collect all sensors I<except> a
-few ones. This option enables you to do that: By setting B<IgnoreSelected> to
-I<true> the effect of B<Sensor> is inversed: All selected sensors are ignored
-and all other sensors are collected.
+=item B<MaxPGVersion> I<version>
-=back
+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.
-=head2 Plugin C<snmp>
+The I<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.
-Since the configuration of the C<snmp plugin> is a little more complicated than
-other plugins, its documentation has been moved to an own manpage,
-L<collectd-snmp(5)>. Please see there for details.
+=back
-=head2 Plugin C<syslog>
+The following predefined queries are available (the definitions can be found
+in the F<postgresql_default.conf> file which, by default, is available at
+C<I<prefix>/share/collectd/>):
=over 4
-=item B<LogLevel> B<debug|info|notice|warning|err>
+=item B<backends>
-Sets the log-level. If, for example, set to B<notice>, then all events with
-severity B<notice>, B<warning>, or B<err> will be submitted to the
-syslog-daemon.
+This query collects the number of backends, i.E<nbsp>e. the number of
+connected clients.
-=back
+=item B<transactions>
-=head2 Plugin C<tcpconns>
+This query collects the numbers of committed and rolled-back transactions of
+the user tables.
-The C<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:
+=item B<queries>
-=over 4
+This query collects the numbers of various table modifications (i.E<nbsp>e.
+insertions, updates, deletions) of the user tables.
-=item B<ListeningPorts> I<true>|I<false>
+=item B<query_plans>
-If this option is set to I<true>, statistics for all local ports for which a
-listening socket exists are collected. The default depends on B<LocalPort> and
-B<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 I<false>, i.E<nbsp>e. only
-the selected ports will be collected unless this option is set to I<true>
-specifically.
+This query collects the numbers of various table scans and returned tuples of
+the user tables.
-=item B<LocalPort> I<Port>
+=item B<table_states>
-Count the connections to a specific local port. This can be used to see how
-many connections are handled by a specific daemon, e.E<nbsp>g. the mailserver.
-You have to specify the port in numeric form, so for the mailserver example
-you'd need to set B<25>.
+This query collects the numbers of live and dead rows in the user tables.
-=item B<RemotePort> I<Port>
+=item B<disk_io>
-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.E<nbsp>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.
+This query collects disk block access counts for user tables.
+
+=item B<disk_usage>
+
+This query collects the on-disk size of the database in bytes.
=back
-=head2 Plugin C<unixsock>
+The B<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
+L<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.
=over 4
-=item B<SocketFile> I<Path>
+=item B<Host> I<hostname>
-Sets the socket-file which is to be created.
+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.
-=item B<SocketGroup> I<Group>
+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 B<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 B<Hostname> and B<FQDNLookup> options.
-If running as root change the group of the UNIX-socket after it has been
-created. Defaults to B<collectd>.
+=item B<Port> I<port>
-=item B<SocketPerms> I<Permissions>
+Specify the TCP port or the local UNIX domain socket file extension of the
+server.
-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
-L<chmod(1)>. Defaults to B<0770>.
+=item B<User> I<username>
-=back
+Specify the username to be used when connecting to the server.
-=head2 Plugin C<uuid>
+=item B<Password> I<password>
-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.
+Specify the password to be used when connecting to the server.
-The following methods are used to find the machine's UUID, in order:
+=item B<SSLMode> I<disable>|I<allow>|I<prefer>|I<require>
-Check I</etc/uuid> (or I<UUIDFile>).
+Specify whether to use an SSL connection when contacting the server. The
+following modes are supported:
-Check for UUID from HAL (L<http://www.freedesktop.org/wiki/Software/hal>)
-if present.
+=over 4
-Check for UUID from C<dmidecode> / SMBIOS.
+=item I<disable>
-Check for UUID from Xen hypervisor.
+Do not use SSL at all.
-If no UUID can be found then the hostname is not modified.
+=item I<allow>
-=over 4
+First, try to connect without using SSL. If that fails, try using SSL.
-=item B<UUIDFile> I<Path>
+=item I<prefer> (default)
-Take the UUID from the given file (default I</etc/uuid>).
+First, try to connect using SSL. If that fails, try without using SSL.
+
+=item I<require>
+
+Use SSL only.
=back
-=head2 Plugin C<vserver>
+=item B<KRBSrvName> I<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
+B<PostgreSQL Documentation> for details.
+
+=item B<Service> I<service_name>
+
+Specify the PostgreSQL service name to use for additional parameters. That
+service has to be defined in F<pg_service.conf> and holds additional
+connection parameters. See the section "The Connection Service File" in the
+B<PostgreSQL Documentation> for details.
+
+=item B<Query> I<query>
+
+Specify a I<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.
+
+=back
+
+=head2 Plugin C<powerdns>
+
+The C<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>
+
+=over 4
+
+=item B<Server> and B<Recursor> block
+
+The B<Server> block defines one authoritative server to query, the B<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 serverE<nbsp>/ recursor
+and is required.
+
+=over 4
+
+=item B<Collect> I<Field>
+
+Using the B<Collect> statement you can select which values to collect. Here,
+you specify the name of the values as used by the PowerDNS servers, e.E<nbsp>g.
+C<dlg-only-drops>, C<answers10-100>.
+
+The method of getting the values differs for B<Server> and B<Recursor> blocks:
+When querying the server a C<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 B<Collect> statement is given, the following B<Server> values will be
+collected:
+
+=over 4
+
+=item latency
+
+=item packetcache-hit
+
+=item packetcache-miss
+
+=item packetcache-size
+
+=item query-cache-hit
+
+=item query-cache-miss
+
+=item recursing-answers
+
+=item recursing-questions
+
+=item tcp-answers
+
+=item tcp-queries
+
+=item udp-answers
+
+=item udp-queries
+
+=back
+
+The following B<Recursor> values will be collected by default:
+
+=over 4
+
+=item noerror-answers
+
+=item nxdomain-answers
+
+=item servfail-answers
+
+=item sys-msec
+
+=item user-msec
+
+=item qa-latency
+
+=item cache-entries
+
+=item cache-hits
+
+=item cache-misses
+
+=item questions
+
+=back
+
+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.
+
+=item B<Socket> I<Path>
+
+Configures the path to the UNIX domain socket to be used when connecting to the
+daemon. By default C<${localstatedir}/run/pdns.controlsocket> will be used for
+an authoritative server and C<${localstatedir}/run/pdns_recursor.controlsocket>
+will be used for the recursor.
+
+=back
+
+=item B<LocalSocket> I<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 I<Path> using the B<LocalSocket> option. The default is
+C<I<prefix>/var/run/collectd-powerdns>.
+
+=back
+
+=head2 Plugin C<processes>
+
+=over 4
+
+=item B<Process> I<Name>
+
+Select more detailed statistics of processes matching this name. The statistics
+collected for these selected processes are size of the resident segment size
+(RSS), user- and system-time used, number of processes and number of threads,
+and minor and major pagefaults.
+
+=item B<ProcessMatch> I<name> I<regex>
+
+Similar to the B<Process> option this allows to select more detailed
+statistics of processes matching the specified I<regex> (see L<regex(7)> for
+details). The statistics of all matching processes are summed up and
+dispatched to the daemon using the specified I<name> as an identifier. This
+allows to "group" several processes together. I<name> must not contain
+slashes.
+
+=back
+
+=head2 Plugin C<rrdcached>
+
+The C<rrdcached> plugin uses the RRDTool accelerator daemon, L<rrdcached(1)>,
+to store values to RRD files in an efficient manner. The combination of the
+C<rrdcached> B<plugin> and the C<rrdcached> B<daemon> is very similar to the
+way the C<rrdtool> plugin works (see below). The added abstraction layer
+provides a number of benefits, though: Because the cache is not within
+C<collectd> anymore, it does not need to be flushed when C<collectd> is to be
+restarted. This results in much shorter (if any) gaps in graphs, especially
+under heavy load. Also, the C<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 C<collectd> to create the appropriate RRD files
+anymore. And even if C<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 B<recommended configuration> is to let C<collectd> and C<rrdcached> run
+on the same host, communicating via a UNIX domain socket. The B<DataDir>
+setting should be set to an absolute path, so that a changed base directory
+does not result in RRD files being createdE<nbsp>/ expected in the wrong place.
+
+=over 4
+
+=item B<DaemonAddress> I<Address>
+
+Address of the daemon as understood by the C<rrdc_connect> function of the RRD
+library. See L<rrdcached(1)> for details. Example:
+
+ <Plugin "rrdcached">
+ DaemonAddress "unix:/var/run/rrdcached.sock"
+ </Plugin>
+
+=item B<DataDir> I<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 C<rrdcached> daemon!
+Use of an absolute path is recommended.
+
+=item B<CreateFiles> B<true>|B<false>
+
+Enables or disables the creation of RRD files. If the daemon is not running
+locally, or B<DataDir> is set to a relative path, this will not work as
+expected. Default is B<true>.
+
+=back
+
+=head2 Plugin C<rrdtool>
+
+You can use the settings B<StepSize>, B<HeartBeat>, B<RRARows>, and B<XFF> to
+fine-tune your RRD-files. Please read L<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.
+
+=over 4
+
+=item B<DataDir> I<Directory>
+
+Set the directory to store RRD-files under. Per default RRD-files are generated
+beneath the daemon's working directory, i.E<nbsp>e. the B<BaseDir>.
+
+=item B<StepSize> I<Seconds>
+
+B<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 C<snmp plugin>, the
+C<exec plugin> or when the daemon is set up to receive data from other hosts.
+
+=item B<HeartBeat> I<Seconds>
+
+B<Force> the heartbeat of newly created RRD-files. This setting should be unset
+in which case the heartbeat is set to twice the B<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.
+
+=item B<RRARows> I<NumRows>
+
+The C<rrdtool plugin> calculates the number of PDPs per CDP based on the
+B<StepSize>, this setting and a timespan. This plugin creates RRD-files with
+three times five RRAs, i. e. five RRAs with the CFs B<MIN>, B<AVERAGE>, and
+B<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.
+
+=item B<RRATimespan> I<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 B<RRARows> above.
+
+=item B<XFF> I<Factor>
+
+Set the "XFiles Factor". The default is 0.1. If unsure, don't set this option.
+
+=item B<CacheFlush> I<Seconds>
+
+When the C<rrdtool> plugin uses a cache (by setting B<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 B<CacheFlush> is set, then the
+entire cache is searched for entries older than B<CacheTimeout> seconds and
+written to disk every I<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.
+
+=item B<CacheTimeout> I<Seconds>
+
+If this option is set to a value greater than zero, the C<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.
+
+=item B<WritesPerSecond> I<Updates>
+
+When collecting many statistics with collectd and the C<rrdtool> plugin, you
+will run serious performance problems. The B<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 C<graph.cgi> script included in the
+C<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<nbsp>e. values that are forced to disk
+by the B<FLUSH> command, are B<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 B<WritesPerSecond> to 30
+updates per second, writing all values to disk will take approximately
+56E<nbsp>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.
+
+=back
+
+=head2 Plugin C<sensors>
+
+The C<sensors plugin> uses B<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 F</etc/sensors.conf>. Read
+L<sensors.conf(5)> for details.
+
+The B<lm_sensors> homepage can be found at
+L<http://secure.netroedge.com/~lm78/>.
+
+=over 4
+
+=item B<Sensor> I<chip-bus-address/type-feature>
+
+Selects the name of the sensor which you want to collect or ignore, depending
+on the B<IgnoreSelected> below. For example, the option "B<Sensor>
+I<it8712-isa-0290/voltage-in1>" will cause collectd to gather data for the
+voltage sensor I<in1> of the I<it8712> on the isa bus at the address 0290.
+
+=item B<IgnoreSelected> I<true>|I<false>
+
+If no configuration if given, the B<sensors>-plugin will collect data from all
+sensors. This may not be practical, especially for uninteresting sensors.
+Thus, you can use the B<Sensor>-option to pick the sensors you're interested
+in. Sometimes, however, it's easier/preferred to collect all sensors I<except> a
+few ones. This option enables you to do that: By setting B<IgnoreSelected> to
+I<true> the effect of B<Sensor> is inverted: All selected sensors are ignored
+and all other sensors are collected.
+
+=back
+
+=head2 Plugin C<snmp>
+
+Since the configuration of the C<snmp plugin> is a little more complicated than
+other plugins, its documentation has been moved to an own manpage,
+L<collectd-snmp(5)>. Please see there for details.
+
+=head2 Plugin C<syslog>
+
+=over 4
+
+=item B<LogLevel> B<debug|info|notice|warning|err>
+
+Sets the log-level. If, for example, set to B<notice>, then all events with
+severity B<notice>, B<warning>, or B<err> will be submitted to the
+syslog-daemon.
+
+Please note that B<debug> is only available if collectd has been compiled with
+debugging support.
+
+=back
+
+=head2 Plugin C<table>
+
+The C<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 L<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 B<Table> blocks, each of which
+configures one file to parse. Within each B<Table> block, there are one or
+more B<Result> blocks, which configure which data to select and how to
+interpret it.
+
+The following options are available inside a B<Table> block:
+
+=over 4
+
+=item B<Instance> I<instance>
+
+If specified, I<instance> is used as the plugin instance. So, in the above
+example, the plugin name C<table-slabinfo> would be used. If omitted, the
+filename of the table is used instead, with all special characters replaced
+with an underscore (C<_>).
+
+=item B<Separator> I<string>
+
+Any character of I<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<nbsp>e. there cannot be any
+empty columns. The plugin uses the L<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 C<\\t>,
+C<\\n> and C<\\r> respectively. Please note that the double backslashes are
+required because of collectd's config parsing.
+
+=back
+
+The following options are available inside a B<Result> block:
+
+=over 4
+
+=item B<Type> I<type>
+
+Sets the type used to dispatch the values to the daemon. Detailed information
+about types and their configuration can be found in L<types.db(5)>. This
+option is mandatory.
+
+=item B<InstancePrefix> I<prefix>
+
+If specified, prepend I<prefix> to the type instance. If omitted, only the
+B<InstancesFrom> option is considered for the type instance.
+
+=item B<InstancesFrom> I<column0> [I<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 (I<->) as separation character. If omitted, only the B<InstancePrefix>
+option is considered for the type instance.
+
+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 B<InstancesFrom>: B<You> have to make
+sure that the table only contains one row.
+
+If neither B<InstancePrefix> nor B<InstancesFrom> is given, the type instance
+will be empty.
+
+=item B<ValuesFrom> I<column0> [I<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 B<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 L<strtoll(3)> and L<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.
+
+=back
+
+=head2 Plugin C<tail>
+
+The C<tail plugin> follows logfiles, just like L<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 L<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 B<File> blocks, each of which configures one
+logfile to parse. Within each B<File> block, there are one or more B<Match>
+blocks, which configure a regular expression to search for.
+
+The B<Instance> option in the B<File> block may be used to set the plugin
+instance. So in the above example the plugin name C<tail-foo> would be used.
+This plugin instance is for all B<Match> blocks that B<follow> it, until the
+next B<Instance> option. This way you can extract several plugin instances from
+one logfile, handy when parsing syslog and the like.
+
+Each B<Match> block has the following options to describe how the match should
+be performed:
+
+=over 4
+
+=item B<Regex> I<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
+L<strtoll(3)> or L<strtod(3)>, depending on the value of C<CounterAdd>, see
+below. Because B<extended> regular expressions are used, you do not need to use
+backslashes for subexpressions! If in doubt, please consult L<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]+)\\)"
+
+=item B<DSType> I<Type>
+
+Sets how the values are cumulated. I<Type> is one of:
+
+=over 4
+
+=item B<GaugeAverage>
+
+Calculate the average.
+
+=item B<GaugeMin>
+
+Use the smallest number only.
+
+=item B<GaugeMax>
+
+Use the greatest number only.
+
+=item B<GaugeLast>
+
+Use the last number found.
+
+=item B<CounterSet>
+
+The matched number is a counter. Simply sets the internal counter to this
+value.
+
+=item B<CounterAdd>
+
+Add the matched value to the internal counter.
+
+=item B<CounterInc>
+
+Increase the internal counter by one. This B<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.
+
+=back
+
+As you'd expect the B<Gauge*> types interpret the submatch as a floating point
+number, using L<strtod(3)>. The B<CounterSet> and B<CounterAdd> interpret the
+submatch as an integer using L<strtoll(3)>. B<CounterInc> does not use the
+submatch at all and it may be omitted in this case.
+
+=item B<Type> I<Type>
+
+Sets the type used to dispatch this value. Detailed information about types and
+their configuration can be found in L<types.db(5)>.
+
+=item B<Instance> I<TypeInstance>
+
+This optional setting sets the type instance to use.
+
+=back
+
+=head2 Plugin C<teamspeak2>
+
+The C<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:
+
+=over 4
+
+=item B<Host> I<hostname/ip>
+
+The hostname or ip which identifies the physical server.
+Default: 127.0.0.1
+
+=item B<Port> I<port>
+
+The query port of the physical server. This needs to be a string.
+Default: "51234"
+
+=item B<Server> I<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<nbsp>e. you B<must>
+use quotes around it! If no such statement is given only global information
+will be collected.
+
+=back
+
+=head2 Plugin C<tcpconns>
+
+The C<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:
+
+=over 4
+
+=item B<ListeningPorts> I<true>|I<false>
+
+If this option is set to I<true>, statistics for all local ports for which a
+listening socket exists are collected. The default depends on B<LocalPort> and
+B<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 I<false>, i.E<nbsp>e. only
+the selected ports will be collected unless this option is set to I<true>
+specifically.
+
+=item B<LocalPort> I<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.E<nbsp>g. the mailserver.
+You have to specify the port in numeric form, so for the mailserver example
+you'd need to set B<25>.
+
+=item B<RemotePort> I<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.E<nbsp>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.
+
+=back
+
+=head2 Plugin C<thermal>
+
+=over 4
+
+=item B<ForceUseProcfs> I<true>|I<false>
+
+By default, the C<thermal> plugin tries to read the statistics from the Linux
+C<sysfs> interface. If that is not available, the plugin falls back to the
+C<procfs> interface. By setting this option to I<true>, you can force the
+plugin to use the latter. This option defaults to I<false>.
+
+=item B<Device> I<Device>
+
+Selects the name of the thermal device that you want to collect or ignore,
+depending on the value of the B<IgnoreSelected> option. This option may be
+used multiple times to specify a list of devices.
+
+=item B<IgnoreSelected> I<true>|I<false>
+
+Invert the selection: If set to true, all devices B<except> the ones that
+match the device names specified by the B<Device> option are collected. By
+default only selected devices are collected if a selection is made. If no
+selection is configured at all, B<all> devices are selected.
+
+=back
+
+=head2 Plugin C<unixsock>
+
+=over 4
+
+=item B<SocketFile> I<Path>
+
+Sets the socket-file which is to be created.
+
+=item B<SocketGroup> I<Group>
+
+If running as root change the group of the UNIX-socket after it has been
+created. Defaults to B<collectd>.
+
+=item B<SocketPerms> I<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
+L<chmod(1)>. Defaults to B<0770>.
+
+=back
+
+=head2 Plugin C<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:
+
+=over 4
+
+=item
+
+Check I</etc/uuid> (or I<UUIDFile>).
+
+=item
+
+Check for UUID from HAL (L<http://www.freedesktop.org/wiki/Software/hal>) if
+present.
+
+=item
+
+Check for UUID from C<dmidecode> / SMBIOS.
+
+=item
+
+Check for UUID from Xen hypervisor.
+
+=back
+
+If no UUID can be found then the hostname is not modified.
+
+=over 4
+
+=item B<UUIDFile> I<Path>
+
+Take the UUID from the given file (default I</etc/uuid>).
+
+=back
+
+=head2 Plugin C<vmem>
+
+The C<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.
+
+=over 4
+
+=item B<Verbose> B<true>|B<false>
+
+Enables verbose collection of information. This will start collecting page
+"actions", e.E<nbsp>g. page allocations, (de)activations, steals and so on.
+Part of these statistics are collected on a "per zone" basis.
+
+=back
+
+=head2 Plugin C<vserver>
This plugin doesn't have any options. B<VServer> support is only available for
Linux. It cannot yet be found in a vanilla kernel, though. To make use of this
The B<VServer> homepage can be found at L<http://linux-vserver.org/>.
+B<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.E<nbsp>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.
+
+=head1 THRESHOLD CONFIGURATION
+
+Starting with version C<4.3.0> collectd has support for B<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
+B<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 B<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 C<Host>,
+C<Plugin>, and C<Type> blocks select the value for which a threshold should be
+configured. The C<Plugin> and C<Type> blocks may be specified further using the
+C<Instance> option. You can combine the block by nesting the blocks, though
+they must be nested in the above order, i.E<nbsp>e. C<Host> may contain either
+C<Plugin> and C<Type> blocks, C<Plugin> may only contain C<Type> blocks and
+C<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 B<must> be
+included in a C<Type> block. Currently the following statements are recognized:
+
+=over 4
+
+=item B<FailureMax> I<Value>
+
+=item B<WarningMax> I<Value>
+
+Sets the upper bound of acceptable values. If unset defaults to positive
+infinity. If a value is greater than B<FailureMax> a B<FAILURE> notification
+will be created. If the value is greater than B<WarningMax> but less than (or
+equal to) B<FailureMax> a B<WARNING> notification will be created.
+
+=item B<FailureMin> I<Value>
+
+=item B<WarningMin> I<Value>
+
+Sets the lower bound of acceptable values. If unset defaults to negative
+infinity. If a value is less than B<FailureMin> a B<FAILURE> notification will
+be created. If the value is less than B<WarningMin> but greater than (or equal
+to) B<FailureMin> a B<WARNING> notification will be created.
+
+=item B<DataSource> I<DSName>
+
+Some data sets have more than one "data source". Interesting examples are the
+C<if_octets> data set, which has received (C<rx>) and sent (C<tx>) bytes and
+the C<disk_ops> data set, which holds C<read> and C<write> operations. The
+system load data set, C<load>, even has three data sources: C<shortterm>,
+C<midterm>, and C<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 B<DataSource> option to have a threshold apply only to
+one data source.
+
+=item B<Invert> B<true>|B<false>
+
+If set to B<true> the range of acceptable values is inverted, i.E<nbsp>e.
+values between B<FailureMin> and B<FailureMax> (B<WarningMin> and
+B<WarningMax>) are not okay. Defaults to B<false>.
+
+=item B<Persist> B<true>|B<false>
+
+Sets how often notifications are generated. If set to B<true> one notification
+will be generated for each value that is out of the acceptable range. If set to
+B<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 B<true> a notification about a
+missing value is generated once every B<Interval> seconds. If set to B<false>
+only one such notification is generated until the value appears again.
+
+=back
+
+=head1 FILTER CONFIGURATION
+
+Starting with collectd 4.6 there is a powerful filtering infrastructure
+implemented in the daemon. The concept has mostly been copied from
+I<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.
+
+=head2 Terminology
+
+The following are the terms used in the remainder of the filter configuration
+documentation. For an ASCII-art schema of the mechanism, see
+L<"General structure"> below.
+
+=over 4
+
+=item B<Match>
+
+A I<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.
+
+=item B<Target>
+
+A I<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 L<"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.
+
+=item B<Rule>
+
+The combination of any number of matches and at least one target is called a
+I<rule>. The target actions will be performed for all values for which B<all>
+matches apply. If the rule does not have any matches associated with it, the
+target action will be performed for all values.
+
+=item B<Chain>
+
+A I<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
+L<"Flow control"> below. After all rules have been checked, the default targets
+will be executed.
+
+=back
+
+=head2 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 !
+ +---------+
+
+=head2 Flow control
+
+There are four ways to control which way a value takes through the filter
+mechanism:
+
+=over 4
+
+=item B<jump>
+
+The built-in B<jump> target can be used to "call" another chain, i.E<nbsp>e.
+process the value with another chain. When the called chain finishes, usually
+the next target or rule after the jump is executed.
+
+=item B<stop>
+
+The stop condition, signaled for example by the built-in target B<stop>, causes
+all processing of the value to be stopped immediately.
+
+=item B<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
+B<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.
+
+=item B<continue>
+
+Most targets will signal the B<continue> condition, meaning that processing
+should continue normally. There is no special built-in target for this
+condition.
+
+=back
+
+=head2 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 C<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 C<show_*> command statistics will be available
+via the C<unixsock> plugin.
+
+=head2 List of configuration options
+
+=over 4
+
+=item B<PreCacheChain> I<ChainName>
+
+=item B<PostCacheChain> I<ChainName>
+
+Configure the name of the "pre-cache chain" and the "post-cache chain". The
+argument is the name of a I<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
+I<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 C<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 C<value> match (see below). If you use the rate stored in
+the cache B<before> the new value is added, you will use the old, B<previous>
+rate. Write plugins may use this rate, too, see the C<csv> plugin, for example.
+The C<unixsock> plugin uses these rates too, to implement the C<GETVAL>
+command.
+
+Last but not last, the B<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.
+
+=item B<Chain> I<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 B<Chain> block, there can be B<Rule> blocks and B<Target> blocks.
+
+=item B<Rule> [I<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 B<Rule> block, there may be any number of B<Match> blocks and there
+must be at least one B<Target> block.
+
+=item B<Match> I<Name>
+
+Adds a match to a B<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 B<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>
+
+=item B<Target> I<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 B<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>
+
+=back
+
+=head2 Built-in targets
+
+The following targets are built into the core daemon and therefore need no
+plugins to be loaded:
+
+=over 4
+
+=item B<return>
+
+Signals the "return" condition, see the L<"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 B<jump> target (see below). This is very similar to the
+B<RETURN> target of iptables, see L<iptables(8)>.
+
+This target does not have any options.
+
+Example:
+
+ Target "return"
+
+=item B<stop>
+
+Signals the "stop" condition, see the L<"Flow control"> section above. This
+causes processing of the value to be aborted immediately. This is similar to
+the B<DROP> target of iptables, see L<iptables(8)>.
+
+This target does not have any options.
+
+Example:
+
+ Target "stop"
+
+=item B<write>
+
+Sends the value to "write" plugins.
+
+Available options:
+
+=over 4
+
+=item B<Plugin> I<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.
+
+=back
+
+If no plugin is explicitly specified, the values will be sent to all available
+write plugins.
+
+Example:
+
+ <Target "write">
+ Plugin "rrdtool"
+ </Target>
+
+=item B<jump>
+
+Starts processing the rules of another chain, see L<"Flow control"> above. If
+the end of that chain is reached, or a stop condition is encountered,
+processing will continue right after the B<jump> target, i.E<nbsp>e. with the
+next target or the next rule. This is similar to the B<-j> command line option
+of iptables, see L<iptables(8)>.
+
+Available options:
+
+=over 4
+
+=item B<Chain> I<Name>
+
+Jumps to the chain I<Name>. This argument is required and may appear only once.
+
+=back
+
+Example:
+
+ <Target "jump">
+ Chain "foobar"
+ </Target>
+
+=back
+
+=head2 Available matches
+
+=over 4
+
+=item B<regex>
+
+Matches a value using regular expressions.
+
+Available options:
+
+=over 4
+
+=item B<Host> I<Regex>
+
+=item B<Plugin> I<Regex>
+
+=item B<PluginInstance> I<Regex>
+
+=item B<Type> I<Regex>
+
+=item B<TypeInstance> I<Regex>
+
+Match values where the given regular expressions match the various fields of
+the identifier of a value. If multiple regular expressions are given, B<all>
+regexen must match for a value to match.
+
+=back
+
+Example:
+
+ <Match "regex">
+ Host "customer[0-9]+"
+ Plugin "^foobar$"
+ </Match>
+
+=item B<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
+C<network> plugin and write them to disk using the C<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 B<outside> a specified time range
+(relative to the server's time), so you can use the B<stop> target (see below)
+to ignore the value, for example.
+
+Available options:
+
+=over 4
+
+=item B<Future> I<Seconds>
+
+Matches all values that are I<ahead> of the server's time by I<Seconds> or more
+seconds. Set to zero for no limit. Either B<Future> or B<Past> must be
+non-zero.
+
+=item B<Past> I<Seconds>
+
+Matches all values that are I<behind> of the server's time by I<Seconds> or
+more seconds. Set to zero for no limit. Either B<Future> or B<Past> must be
+non-zero.
+
+=back
+
+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.
+
+=item B<value>
+
+Matches the actual value of data sources against given minimumE<nbsp>/ 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:
+
+=over 4
+
+=item B<Min> I<Value>
+
+Sets the smallest value which still results in a match. If unset, behaves like
+negative infinity.
+
+=item B<Max> I<Value>
+
+Sets the largest value which still results in a match. If unset, behaves like
+positive infinity.
+
+=item B<Invert> B<true>|B<false>
+
+Inverts the selection. If the B<Min> and B<Max> settings result in a match,
+no-match is returned and vice versa. Please note that the B<Invert> setting
+only effects how B<Min> and B<Max> are applied to a specific value. Especially
+the B<DataSource> and B<Satisfy> settings (see below) are not inverted.
+
+=item B<DataSource> I<DSName> [I<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 B<Invert> setting).
+
+=item B<Satisfy> B<Any>|B<All>
+
+Specifies how checking with several data sources is performed. If set to
+B<Any>, the match succeeds if one of the data sources is in the configured
+range. If set to B<All> the match only succeeds if all data sources are within
+the configured range. Default is B<All>.
+
+Usually B<All> is used for positive matches, B<Any> is used for negative
+matches. This means that with B<All> you usually check that all values are in a
+"good" range, while with B<Any> you check if any value is within a "bad" range
+(or outside the "good" range).
+
+=back
+
+Either B<Min> or B<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>
+
+=back
+
+=head2 Available targets
+
+=over 4
+
+=item B<notification>
+
+Creates and dispatches a notification.
+
+Available options:
+
+=over 4
+
+=item B<Message> I<String>
+
+This required option sets the message of the notification. The following
+placeholders will be replaced by an appropriate value:
+
+=over 4
+
+=item B<%{host}>
+
+=item B<%{plugin}>
+
+=item B<%{plugin_instance}>
+
+=item B<%{type}>
+
+=item B<%{type_instance}>
+
+These placeholders are replaced by the identifier field of the same name.
+
+=item B<%{ds:>I<name>B<}>
+
+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 B<set> or B<replace> targets, see below), it may not be possible to
+convert counter values to rates.
+
+=back
+
+Please note that these placeholders are B<case sensitive>!
+
+=item B<Severity> B<"FATAL">|B<"WARNING">|B<"OKAY">
+
+Sets the severity of the message. If omitted, the severity B<"WARNING"> is
+used.
+
+=back
+
+Example:
+
+ <Target "notification">
+ Message "Oops, the %{type_instance} temperature is currently %{ds:value}!"
+ Severity "WARNING"
+ </Target>
+
+=item B<replace>
+
+Replaces parts of the identifier using regular expressions.
+
+Available options:
+
+=over 4
+
+=item B<Host> I<Regex> I<Replacement>
+
+=item B<Plugin> I<Regex> I<Replacement>
+
+=item B<PluginInstance> I<Regex> I<Replacement>
+
+=item B<TypeInstance> I<Regex> I<Replacement>
+
+Match the appropriate field with the given regular expression I<Regex>. If the
+regular expression matches, that part that matches is replaced with
+I<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.
+
+=back
+
+Example:
+
+ <Target "replace">
+ # Replace "example.net" with "example.com"
+ Host "\\<example.net\\>" "example.com"
+
+ # Strip "www." from hostnames
+ Host "\\<www\\." ""
+ </Target>
+
+=item B<set>
+
+Sets part of the identifier of a value to a given string.
+
+Available options:
+
+=over 4
+
+=item B<Host> I<String>
+
+=item B<Plugin> I<String>
+
+=item B<PluginInstance> I<String>
+
+=item B<TypeInstance> I<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.
+
+=back
+
+Example:
+
+ <Target "set">
+ PluginInstance "coretemp"
+ TypeInstance "core3"
+ </Target>
+
+=back
+
+=head2 Backwards compatibility
+
+If you use collectd with an old configuration, i.E<nbsp>e. one without a
+B<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 B<PostCacheChain>, the B<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.
+
+=head2 Examples
+
+Ignore all values, where the hostname does not contain a dot, i.E<nbsp>e. can't
+be an FQDN.
+
+ <Chain "PreCache">
+ <Rule "no_fqdn">
+ <Match "regex">
+ Host "^[^\.]*$"
+ </Match>
+ Target "stop"
+ </Rule>
+ Target "write"
+ </Chain>
+
=head1 SEE ALSO
L<collectd(1)>,
L<collectd-exec(5)>,
L<collectd-perl(5)>,
L<collectd-unixsock(5)>,
+L<types.db(5)>,
L<hddtemp(8)>,
+L<iptables(8)>,
L<kstat(3KSTAT)>,
L<mbmon(1)>,
+L<psql(1)>,
+L<regex(7)>,
L<rrdtool(1)>,
L<sensors(1)>
projects / collectd.git / blobdiff