values lead to a higher system load produced by collectd, while higher values
lead to more coarse statistics.
+=item B<Timeout> I<Iterations>
+
+Consider a value list "missing" when no update has been read or received for
+I<Iterations> iterations. By default, I<collectd> considers a value list
+missing when no update has been received for twice the update interval. Since
+this setting uses iterations, the maximum allowed time without update depends
+on the I<Interval> information contained in each value list. This is used in
+the I<Threshold> configuration to dispatch notifications about missing values,
+see L<"THRESHOLD CONFIGURATION"> below.
+
=item B<ReadThreads> I<Num>
Number of threads to start for reading plugins. The default value is B<5>, but
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.
+This is done using a lookup of the name returned by C<gethostname>. This option
+is enabled by default.
=item B<PreCacheChain> I<ChainName>
means to concatenate the guest name and UUID (with a literal colon character
between, thus I<"foo:1234-1234-1234-1234">).
+=item B<InterfaceFormat> B<name>|B<address>
+
+When the libvirt plugin logs interface data, it sets the name of the collected
+data according to this setting. The default is to use the path as provided by
+the hypervisor (the "dev" property of the target node), which is equal to
+setting B<name>.
+
+B<address> means use the interface's mac address. This is useful since the
+interface path might change between reboots of a guest or across migrations.
+
=back
=head2 Plugin C<logfile>
=back
+=head2 Plugin C<modbus>
+
+The B<modbus plugin> connects to a Modbus "slave" via Modbus/TCP and reads
+register values. It supports reading single registers (unsigned 16E<nbsp>bit
+values), large integer values (unsigned 32E<nbsp>bit values) and floating point
+values (two registers interpreted as IEEE floats in big endian notation).
+
+Synopsis:
+
+ <Data "voltage-input-1">
+ RegisterBase 0
+ RegisterType float
+ Type voltage
+ Instance "input-1"
+ </Data>
+
+ <Data "voltage-input-2">
+ RegisterBase 2
+ RegisterType float
+ Type voltage
+ Instance "input-2"
+ </Data>
+
+ <Host "modbus.example.com">
+ Address "192.168.0.42"
+ Port "502"
+ Interval 60
+
+ <Slave 1>
+ Instance "power-supply"
+ Collect "voltage-input-1"
+ Collect "voltage-input-2"
+ </Slave>
+ </Host>
+
+=over 4
+
+=item E<lt>B<Data> I<Name>E<gt> blocks
+
+Data blocks define a mapping between register numbers and the "types" used by
+I<collectd>.
+
+Within E<lt>DataE<nbsp>/E<gt> blocks, the following options are allowed:
+
+=over 4
+
+=item B<RegisterBase> I<Number>
+
+Configures the base register to read from the device. If the option
+B<RegisterType> has been set to B<Uint32> or B<Float>, this and the next
+register will be read (the register number is increased by one).
+
+=item B<RegisterType> B<Uint16>|B<Uint32>|B<Float>
+
+Specifies what kind of data is returned by the device. If the type is B<Uint32>
+or B<Float>, two 16E<nbsp>bit registers will be read and the data is combined
+into one value. Defaults to B<Uint16>.
+
+=item B<Type> I<Type>
+
+Specifies the "type" (data set) to use when dispatching the value to
+I<collectd>. Currently, only data sets with exactly one data source are
+supported.
+
+=item B<Instance> I<Instance>
+
+Sets the type instance to use when dispatching the value to I<collectd>. If
+unset, an empty string (no type instance) is used.
+
+=back
+
+=item E<lt>B<Host> I<Name>E<gt> blocks
+
+Host blocks are used to specify to which hosts to connect and what data to read
+from their "slaves". The string argument I<Name> is used as hostname when
+dispatching the values to I<collectd>.
+
+Within E<lt>HostE<nbsp>/E<gt> blocks, the following options are allowed:
+
+=over 4
+
+=item B<Address> I<Hostname>
+
+Specifies the node name (the actual network address) used to connect to the
+host. This may be an IP address or a hostname. Please note that the used
+I<libmodbus> library only supports IPv4 at the moment.
+
+=item B<Port> I<Service>
+
+Specifies the port used to connect to the host. The port can either be given as
+a number or as a service name. Please note that the I<Service> argument must be
+a string, even if ports are given in their numerical form. Defaults to "502".
+
+=item B<Interval> I<Interval>
+
+Sets the interval (in seconds) in which the values will be collected from this
+host. By default the global B<Interval> setting will be used.
+
+=item E<lt>B<Slave> I<ID>E<gt>
+
+Over each TCP connection, multiple Modbus devices may be reached. The slave ID
+is used to specify which device should be addressed. For each device you want
+to query, one B<Slave> block must be given.
+
+Within E<lt>SlaveE<nbsp>/E<gt> blocks, the following options are allowed:
+
+=over 4
+
+=item B<Instance> I<Instance>
+
+Specify the plugin instance to use when dispatching the values to I<collectd>.
+By default "slave_I<ID>" is used.
+
+=item B<Collect> I<DataName>
+
+Specifies which data to retrieve from the device. I<DataName> must be the same
+string as the I<Name> argument passed to a B<Data> block. You can specify this
+option multiple times to collect more than one value from a slave. At least one
+B<Collect> option is mandatory.
+
+=back
+
+=back
+
+=back
+
=head2 Plugin C<mysql>
The C<mysql plugin> requires B<mysqlclient> to be installed. It connects to
This feature is only available if the I<network> plugin was linked with
I<libgcrypt>.
+=item B<Interface> I<Interface name>
+
+Set the outgoing interface for IP packets. This applies at least
+to IPv6 packets and if possible to IPv4. If this option is not applicable,
+undefined or a non-existent interface name is specified, the default
+behaviour is to let the kernel choose the appropriate interface. Be warned
+that the manual selection of an interface for unicast traffic is only
+necessary in rare cases.
+
=back
=item B<E<lt>Listen> I<Host> [I<Port>]B<E<gt>>
using L<stat(2)>. If the file has been changed, the contents is re-read. While
the file is being read, it is locked using L<fcntl(2)>.
+=item B<Interface> I<Interface name>
+
+Set the incoming interface for IP packets explicitly. This applies at least
+to IPv6 packets and if possible to IPv4. If this option is not applicable,
+undefined or a non-existent interface name is specified, the default
+behaviour is, to let the kernel choose the appropriate interface. Thus incoming
+traffic gets only accepted, if it arrives on the given interface.
+
=back
=item B<TimeToLive> I<1-255>
</Database>
<Database bar>
+ Interval 300
Service "service_name"
Query backend # predefined
Query rt36_tickets
=item I<interval>
-The interval collectd is using (as specified by the B<Interval> option).
+The interval with which this database is queried (as specified by the database
+specific or global B<Interval> options).
=back
=over 4
+=item B<Interval> I<seconds>
+
+Specify the interval with which the database should be queried. The default is
+to use the global B<Interval> setting.
+
=item B<Host> I<hostname>
Specify the hostname or IP of the PostgreSQL server to connect to. If the
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.
+not received for B<Timeout> iterations. The B<Timeout> configuration option is
+explained in section L<"GLOBAL OPTIONS">. If, for example, B<Timeout> is set to
+"2" (the default) and 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.
the identifier of a value. If multiple regular expressions are given, B<all>
regexen must match for a value to match.
+=item B<Invert> B<false>|B<true>
+
+When set to B<true>, the result of the match is inverted, i.e. all value lists
+where all regular expressions apply are not matched, all other value lists are
+matched. Defaults to B<false>.
+
=back
Example: