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
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
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
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
=back
+=head2 Plugin C<onewire>
+
+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.
+
+=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>
+
+=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<perl>
This plugin embeds a Perl-interpreter into collectd and provides an interface
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. The 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.
+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>
+ Query "SELECT magic, spells FROM wizard WHERE host = $1;"
+ Param hostname
+ Column gauge magic
+ Column counter spells
+ </Query>
+
<Database foo>
Host "hostname"
Port "5432"
Password "secret"
SSLMode "prefer"
KRBSrvName "kerberos_service_name"
+ Query magic
</Database>
<Database bar>
Service "service_name"
</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. The
+following configuration options are available to define the query:
+
=over 4
-=item B<Database> block
+=item B<Query> I<sql query>
+
+Specify the I<sql query> 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.
+
+=item B<Param> I<hostname>|I<database>|I<username>
+
+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.
+
+=back
+
+=item B<Column> I<type> [I<type instance>]
+
+Specify the I<type> and optional I<type instance> used to dispatch the value
+of each result column. Detailed information about types and their
+configuration can be found in L<types.db(5)>. The number and order of the
+B<Column> options has to match the columns of the query result.
+
+=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
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
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>
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