X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Fcollectd.conf.pod;h=f7f178c093fb587ab087d0995fa94f7f4fb7b115;hb=c16c87053165a07fdeb6d5469085142ff87a2ecb;hp=d50f7ce57be60858782332c1d16740f19fe5981e;hpb=bd702098d986e4985fdf4f7f7658ff4532d96533;p=collectd.git

diff --git a/src/collectd.conf.pod b/src/collectd.conf.pod
index d50f7ce5..f7f178c0 100644
--- a/src/collectd.conf.pod
+++ b/src/collectd.conf.pod
@@ -30,7 +30,11 @@ section-start or -end. Empty lines and everything after the hash-symbol `#' is
 ignored. Values are either string, enclosed in double-quotes,
 (floating-point-)numbers or a boolean expression, i.E<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
@@ -122,6 +126,14 @@ 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
@@ -232,6 +244,19 @@ Optional user name needed for authentication.
 
 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
@@ -240,6 +265,150 @@ 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
@@ -256,6 +425,9 @@ installed and an "cpu governor" (that's a kernel module) is loaded.
 
 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>
 
@@ -265,6 +437,316 @@ 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.)
+
+Please note that some databases, for example B<Oracle>, will fail if you
+include a semicolon at the end of the statement.
+
+=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 join together with the dashes I<("-")> as separation character.
+
+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
+
 =head2 Plugin C<df>
 
 =over 4
@@ -403,6 +885,83 @@ 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>
 
 To get values from B<hddtemp> collectd connects to B<localhost> (127.0.0.1),
@@ -450,7 +1009,7 @@ similar interfaces. Thus, you can use the B<Interface>-option to pick the
 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
@@ -471,6 +1030,20 @@ 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>
@@ -508,7 +1081,7 @@ irqs. This may not be practical, especially if no interrupts happen. Thus, you
 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
@@ -615,6 +1188,10 @@ Prefix all lines printed by the current time. Defaults to B<true>.
 
 =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.
@@ -695,6 +1272,23 @@ Password needed to log into the database.
 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>
@@ -769,7 +1363,7 @@ Here are some examples to help you understand the above text more easily:
 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
@@ -877,6 +1471,87 @@ and are checked by default depends on the distribution you use.
 
 =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
@@ -909,39 +1584,521 @@ L<upsc(8)>.
 
 =back
 
-=head2 Plugin C<perl>
+=head2 Plugin C<onewire>
 
-This plugin embeds a Perl-interpreter into collectd and provides an interface
-to collectd's plugin system. See L<collectd-perl(5)> for its documentation.
+B<EXPERIMENTAL!> See notes below.
 
-=head2 Plugin C<ping>
+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<Host> I<IP-address>
+=item B<Device> I<Device>
 
-Host to ping periodically. This option may be repeated several times to ping
-multiple hosts.
+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>.
 
-=item B<TTL> I<0-255>
+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:
 
-Sets the Time-To-Live of generated ICMP packets.
+  <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
 
-=head2 Plugin C<powerdns>
+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>:)
 
-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.
+=head2 Plugin C<openvpn>
 
-  <Plugin "powerdns">
-    <Server "server_name">
-      Collect "latency"
-      Collect "udp-answers" "udp-queries"
-      Socket "/var/run/pdns.controlsocket"
+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
+to collectd's plugin system. See L<collectd-perl(5)> for its documentation.
+
+=head2 Plugin C<ping>
+
+=over 4
+
+=item B<Host> I<IP-address>
+
+Host to ping periodically. This option may be repeated several times to ping
+multiple hosts.
+
+=item B<TTL> I<0-255>
+
+Sets the Time-To-Live of generated ICMP packets.
+
+=back
+
+=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<MinVersion> and B<MaxVersion> 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<Statement> I<sql query statement>
+
+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<'>).
+
+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.
+
+The returned lines will be handled separately one after another.
+
+=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 I<hostname>
+
+The configured hostname of the database connection. If a UNIX domain socket is
+used, the parameter expands to "localhost".
+
+=item I<database>
+
+The name of the database of the current connection.
+
+=item I<username>
+
+The username used to connect to the database.
+
+=item I<interval>
+
+The interval collectd is using (as specified by the B<Interval> option).
+
+=back
+
+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<Type> I<type>
+
+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.
+
+This option is required inside a B<Result> block.
+
+=item B<InstancePrefix> I<prefix>
+
+=item B<InstancesFrom> I<column0> [I<column1> ...]
+
+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.
+
+The plugin itself does not check whether or not all built instances are
+different. It is your responsibility to assure that each is unique.
+
+Both options are optional. If none is specified, the type instance will be
+empty.
+
+=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 as explained above. If you specify too many
+or not enough columns, the plugin will complain about that and no data will be
+submitted to the daemon.
+
+The actual data type, as seen by PostgreSQL, is not that important as long as
+it represents numbers. The plugin will automatically cast the values to the
+right type if it know how to do that. For that, it uses the L<strtoll(3)> and
+L<strtod(3)> functions, so anything supported by those functions is supported
+by the plugin as well.
+
+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.
+
+=item B<Column> I<type> [I<type instance>]
+
+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:
+
+  <Result>
+    Type I<type>
+    InstancePrefix I<type instance>
+    ValuesFrom I<name of the x. column>
+  </Result>
+
+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<MinVersion> I<version>
+
+=item B<MaxVersion> I<version>
+
+Specify the minimum or maximum version of PostgreSQL that this query should be
+used with. Some statistics might only be available with certain versions of
+PostgreSQL. This allows you to specify multiple queries with the same name but
+which apply to different versions, thus allowing you to use the same
+configuration in a heterogeneous environment.
+
+The 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.
+
+=item B<MinPGVersion> I<version>
+
+=item B<MaxPGVersion> I<version>
+
+These are deprecated synonyms for B<MinVersion> and B<MaxVersion>
+respectively. They will be removed in version 5 of collectd.
+
+=back
+
+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<backends>
+
+This query collects the number of backends, i.E<nbsp>e. the number of
+connected clients.
+
+=item B<transactions>
+
+This query collects the numbers of committed and rolled-back transactions of
+the user tables.
+
+=item B<queries>
+
+This query collects the numbers of various table modifications (i.E<nbsp>e.
+insertions, updates, deletions) of the user tables.
+
+=item B<query_plans>
+
+This query collects the numbers of various table scans and returned tuples of
+the user tables.
+
+=item B<table_states>
+
+This query collects the numbers of live and dead rows in the user tables.
+
+=item B<disk_io>
+
+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
+
+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<Host> I<hostname>
+
+Specify the hostname or IP of the PostgreSQL server to connect to. If the
+value begins with a slash, it is interpreted as the directory name in which to
+look for the UNIX domain socket.
+
+This option is also used to determine the hostname that is associated with a
+collected data set. If it has been omitted or either begins with with a slash
+or equals 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.
+
+=item B<Port> I<port>
+
+Specify the TCP port or the local UNIX domain socket file extension of the
+server.
+
+=item B<User> I<username>
+
+Specify the username to be used when connecting to the server.
+
+=item B<Password> I<password>
+
+Specify the password to be used when connecting to the server.
+
+=item B<SSLMode> I<disable>|I<allow>|I<prefer>|I<require>
+
+Specify whether to use an SSL connection when contacting the server. The
+following modes are supported:
+
+=over 4
+
+=item I<disable>
+
+Do not use SSL at all.
+
+=item I<allow>
+
+First, try to connect without using SSL. If that fails, try using SSL.
+
+=item I<prefer> (default)
+
+First, try to connect using SSL. If that fails, try without using SSL.
+
+=item I<require>
+
+Use SSL only.
+
+=back
+
+=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"
@@ -1073,6 +2230,65 @@ 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>
@@ -1133,7 +2349,7 @@ 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)
+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,
@@ -1152,6 +2368,30 @@ 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>
@@ -1180,7 +2420,7 @@ 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
+I<true> the effect of B<Sensor> is inverted: All selected sensors are ignored
 and all other sensors are collected.
 
 =back
@@ -1383,6 +2623,32 @@ 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
@@ -1473,6 +2739,12 @@ the F</proc/virtual> filesystem that is required by this plugin.
 
 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
@@ -1600,6 +2872,651 @@ 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)>,
@@ -1608,8 +3525,11 @@ 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)>