BaseDir "/path/to/data/"
PIDFile "/path/to/pidfile/collectd.pid"
Server "123.123.123.123" 12345
-
+
LoadPlugin cpu
LoadPlugin load
+
+ <LoadPlugin df>
+ Interval 3600
+ </LoadPlugin>
+
LoadPlugin ping
-
<Plugin ping>
Host "example.org"
Host "provider.net"
<LoadPlugin perl>
Globals true
+ Interval 10
</LoadPlugin>
=over 4
either C<perl> or C<python>, the default is changed to enabled in order to keep
the average user from ever having to deal with this low level linking stuff.
+=item B<Interval> I<Seconds>
+
+Sets a plugin-specific interval for collecting metrics. This overrides the
+global B<Interval> setting. If a plugin provides own support for specifying an
+interval, that setting will take precedence.
+
=back
=item B<Include> I<Path>
require external configuration, too. The C<apache plugin>, for example,
required C<mod_status> to be configured in the webserver you're going to
collect data from. These plugins are listed below as well, even if they don't
-require any configuration within collectd's configfile.
+require any configuration within collectd's configuration file.
A list of all plugins and a short summary for each plugin can be found in the
F<README> file shipped with the sourcecode and hopefully binary packets as
well.
+=head2 Plugin C<aggregation>
+
+The I<Aggregation plugin> makes it possible to aggregate several values into
+one using aggregation functions such as I<sum>, I<average>, I<min> and I<max>.
+This can be put to a wide variety of uses, e.g. average and total CPU
+statistics for your entire fleet.
+
+The grouping is powerful but, as with many powerful tools, may be a bit
+difficult to wrap your head around. The grouping will therefore be
+demonstrated using an example: The average and sum of the CPU usage across
+all CPUs of each host is to be calculated.
+
+To select all the affected values for our example, set C<Plugin cpu> and
+C<Type cpu>. The other values are left unspecified, meaning "all values". The
+I<Host>, I<Plugin>, I<PluginInstance>, I<Type> and I<TypeInstance> options
+work as if they were specified in the C<WHERE> clause of an C<SELECT> SQL
+statement.
+
+ Plugin "cpu"
+ Type "cpu"
+
+Although the I<Host>, I<PluginInstance> (CPU number, i.e. 0, 1, 2, ...) and
+I<TypeInstance> (idle, user, system, ...) fields are left unspecified in the
+example, the intention is to have a new value for each host / type instance
+pair. This is achieved by "grouping" the values using the C<GroupBy> option.
+It can be specified multiple times to group by more than one field.
+
+ GroupBy "Host"
+ GroupBy "TypeInstance"
+
+We do neither specify nor group by I<plugin instance> (the CPU number), so all
+metrics that differ in the CPU number only will be aggregated. Each
+aggregation needs I<at least one> such field, otherwise no aggregation would
+take place.
+
+The full example configuration looks like this:
+
+ <Plugin "aggregation">
+ <Aggregation>
+ Plugin "cpu"
+ Type "cpu"
+
+ GroupBy "Host"
+ GroupBy "TypeInstance"
+
+ CalculateSum true
+ CalculateAverage true
+ </Aggregation>
+ </Plugin>
+
+There are a couple of limitations you should be aware of:
+
+=over 4
+
+=item
+
+The I<Type> cannot be left unspecified, because it is not reasonable to add
+apples to oranges. Also, the internal lookup structure won't work if you try
+to group by type.
+
+=item
+
+There must be at least one unspecified, ungrouped field. Otherwise nothing
+will be aggregated.
+
+=back
+
+As you can see in the example above, each aggregation has its own
+B<Aggregation> block. You can have multiple aggregation blocks and aggregation
+blocks may match the same values, i.e. one value list can update multiple
+aggregations. The following options are valid inside B<Aggregation> blocks:
+
+=over 4
+
+=item B<Host> I<Host>
+
+=item B<Plugin> I<Plugin>
+
+=item B<PluginInstance> I<PluginInstance>
+
+=item B<Type> I<Type>
+
+=item B<TypeInstance> I<TypeInstance>
+
+Selects the value lists to be added to this aggregation. B<Type> must be a
+valid data set name, see L<types.db(5)> for details.
+
+=item B<GroupBy> B<Host>|B<Plugin>|B<PluginInstance>|B<TypeInstance>
+
+Group valued by the specified field. The B<GroupBy> option may be repeated to
+group by multiple fields.
+
+=item B<CalculateNum> B<true>|B<false>
+
+=item B<CalculateSum> B<true>|B<false>
+
+=item B<CalculateAverage> B<true>|B<false>
+
+=item B<CalculateMinimum> B<true>|B<false>
+
+=item B<CalculateMaximum> B<true>|B<false>
+
+=item B<CalculateStddev> B<true>|B<false>
+
+Boolean options for enabling calculation of the number of value lists, their
+sum, average, minimum, maximum andE<nbsp>/ or standard deviation. All options
+are disabled by default.
+
+=back
+
=head2 Plugin C<amqp>
The I<AMQMP plugin> can be used to communicate with other instances of
statistics provided by PostgreSQL without the need to upgrade your collectd
installation.
+Starting with version 5.2, the C<postgresql> plugin supports writing data to
+PostgreSQL databases as well. This has been implemented in a generic way. You
+need to specify an SQL statement which will then be executed by collectd in
+order to write the data (see below for details). The benefit of that approach
+is that there is no fixed database layout. Rather, the layout may be optimized
+for the current setup.
+
The B<PostgreSQL Documentation> manual can be found at
L<http://www.postgresql.org/docs/manuals/>.
</Result>
</Query>
+ <Writer sqlstore>
+ Statement "SELECT collectd_insert($1, $2, $3, $4, $5, $6, $7, $8, $9);"
+ StoreRates true
+ </Writer>
+
<Database foo>
Host "hostname"
Port "5432"
Query backend # predefined
Query rt36_tickets
</Database>
+
+ <Database qux>
+ # ...
+ Writer sqlstore
+ CommitInterval 10
+ </Database>
</Plugin>
The B<Query> block defines one database query which may later be used by a
=back
+In addition, the following detailed queries are available by default. Please
+note that each of those queries collects information B<by table>, thus,
+potentially producing B<a lot> of data. For details see the description of the
+non-by_table queries above.
+
+=over 4
+
+=item B<queries_by_table>
+
+=item B<query_plans_by_table>
+
+=item B<table_states_by_table>
+
+=item B<disk_io_by_table>
+
+=back
+
+The B<Writer> block defines a PostgreSQL writer backend. It accepts a single
+mandatory argument specifying the name of the writer. This will then be used
+in the B<Database> specification in order to activate the writer instance. The
+names of all writers have to be unique. The following options may be
+specified:
+
+=over 4
+
+=item B<Statement> I<sql statement>
+
+This mandatory option specifies the SQL statement that will be executed for
+each submitted value. A single SQL statement is allowed only. Anything after
+the first semicolon will be ignored.
+
+Nine parameters will be passed to the statement and should be specified as
+tokens B<$1>, B<$2>, through B<$9> in the statement string. The following
+values are made available through those parameters:
+
+=over 4
+
+=item B<$1>
+
+The timestamp of the queried value as a floating point number.
+
+=item B<$2>
+
+The hostname of the queried value.
+
+=item B<$3>
+
+The plugin name of the queried value.
+
+=item B<$4>
+
+The plugin instance of the queried value. This value may be B<NULL> if there
+is no plugin instance.
+
+=item B<$5>
+
+The type of the queried value (cf. L<types.db(5)>).
+
+=item B<$6>
+
+The type instance of the queried value. This value may be B<NULL> if there is
+no type instance.
+
+=item B<$7>
+
+An array of names for the submitted values (i.E<nbsp>e., the name of the data
+sources of the submitted value-list).
+
+=item B<$8>
+
+An array of types for the submitted values (i.E<nbsp>e., the type of the data
+sources of the submitted value-list; C<counter>, C<gauge>, ...). Note, that if
+B<StoreRates> is enabled (which is the default, see below), all types will be
+C<gauge>.
+
+=item B<$9>
+
+An array of the submitted values. The dimensions of the value name and value
+arrays match.
+
+=back
+
+In general, it is advisable to create and call a custom function in the
+PostgreSQL database for this purpose. Any procedural language supported by
+PostgreSQL will do (see chapter "Server Programming" in the PostgreSQL manual
+for details).
+
+=item B<StoreRates> B<false>|B<true>
+
+If set to B<true> (the default), convert counter values to rates. If set to
+B<false> counter values are stored as is, i.E<nbsp>e. as an increasing integer
+number.
+
+=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
Specify the interval with which the database should be queried. The default is
to use the global B<Interval> setting.
+=item B<CommitInterval> I<seconds>
+
+This option may be used for database connections which have "writers" assigned
+(see above). If specified, it causes a writer to put several updates into a
+single transaction. This transaction will last for the specified amount of
+time. By default, each update will be executed in a separate transaction. Each
+transaction generates a fair amount of overhead which can, thus, be reduced by
+activating this option. The draw-back is, that data covering the specified
+amount of time will be lost, for example, if a single statement within the
+transaction fails or if the database server crashes.
+
=item B<Host> I<hostname>
Specify the hostname or IP of the PostgreSQL server to connect to. If the
=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.
+Specifies a I<query> which should be executed in the context of 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" (unless a B<Writer>
+has been specified). Else, the specified queries are used only.
+
+=item B<Writer> I<writer>
+
+Assigns the specified I<writer> backend to the database connection. This
+causes all collected data to be send to the database using the settings
+defined in the writer configuration (see the section "FILTER CONFIGURATION"
+below for details on how to selectively send data to certain plugins).
+
+Each writer will register a flush callback which may be used when having long
+transactions enabled (see the B<CommitInterval> option above). When issuing
+the B<FLUSH> command (see L<collectd-unixsock(5)> for details) the current
+transaction will be committed right away. Two different kinds of flush
+callbacks are available with the C<postgresql> plugin:
+
+=over 4
+
+=item B<postgresql>
+
+Flush all writer backends.
+
+=item B<postgresql->I<database>
+
+Flush all writers of the specified I<database> only.
+
+=back
=back