+=item B<AlwaysAppendDS> B<false>|B<true>
+
+If set to B<true>, append the name of the I<Data Source> (DS) to the "metric"
+identifier. If set to B<false> (the default), this is only done when there is
+more than one DS.
+
+=item B<PreserveSeparator> B<false>|B<true>
+
+If set to B<false> (the default) the C<.> (dot) character is replaced with
+I<EscapeCharacter>. Otherwise, if set to B<true>, the C<.> (dot) character
+is preserved, i.e. passed through.
+
+=item B<DropDuplicateFields> B<false>|B<true>
+
+If set to B<true>, detect and remove duplicate components in Graphite metric
+names. For example, the metric name C<host.load.load.shortterm> will
+be shortened to C<host.load.shortterm>.
+
+=back
+
+=head2 Plugin C<write_log>
+
+The C<write_log> plugin writes metrics as INFO log messages.
+
+This plugin supports two output formats: I<Graphite> and I<JSON>.
+
+Synopsis:
+
+ <Plugin write_log>
+ Format Graphite
+ </Plugin>
+
+=over 4
+
+=item B<Format> I<Format>
+
+The output format to use. Can be one of C<Graphite> or C<JSON>.
+
+=back
+
+=head2 Plugin C<write_tsdb>
+
+The C<write_tsdb> plugin writes data to I<OpenTSDB>, a scalable open-source
+time series database. The plugin connects to a I<TSD>, a masterless, no shared
+state daemon that ingests metrics and stores them in HBase. The plugin uses
+I<TCP> over the "line based" protocol with a default port 4242. The data will
+be sent in blocks of at most 1428 bytes to minimize the number of network
+packets.
+
+Synopsis:
+
+ <Plugin write_tsdb>
+ <Node "example">
+ Host "tsd-1.my.domain"
+ Port "4242"
+ HostTags "status=production"
+ </Node>
+ </Plugin>
+
+The configuration consists of one or more E<lt>B<Node>E<nbsp>I<Name>E<gt>
+blocks. Inside the B<Node> blocks, the following options are recognized:
+
+=over 4
+
+=item B<Host> I<Address>
+
+Hostname or address to connect to. Defaults to C<localhost>.
+
+=item B<Port> I<Service>
+
+Service name or port number to connect to. Defaults to C<4242>.
+
+
+=item B<HostTags> I<String>
+
+When set, I<HostTags> is added to the end of the metric. It is intended to be
+used for name=value pairs that the TSD will tag the metric with. Dots and
+whitespace are I<not> escaped in this string.
+
+=item B<StoreRates> B<false>|B<true>
+
+If set to B<true>, convert counter values to rates. If set to B<false>
+(the default) counter values are stored as is, as an increasing
+integer number.
+
+=item B<AlwaysAppendDS> B<false>|B<true>
+
+If set the B<true>, append the name of the I<Data Source> (DS) to the "metric"
+identifier. If set to B<false> (the default), this is only done when there is
+more than one DS.
+
+=back
+
+=head2 Plugin C<write_mongodb>
+
+The I<write_mongodb plugin> will send values to I<MongoDB>, a schema-less
+NoSQL database.
+
+B<Synopsis:>
+
+ <Plugin "write_mongodb">
+ <Node "default">
+ Host "localhost"
+ Port "27017"
+ Timeout 1000
+ StoreRates true
+ </Node>
+ </Plugin>
+
+The plugin can send values to multiple instances of I<MongoDB> by specifying
+one B<Node> block for each instance. Within the B<Node> blocks, the following
+options are available:
+
+=over 4
+
+=item B<Host> I<Address>
+
+Hostname or address to connect to. Defaults to C<localhost>.
+
+=item B<Port> I<Service>
+
+Service name or port number to connect to. Defaults to C<27017>.
+
+=item B<Timeout> I<Milliseconds>
+
+Set the timeout for each operation on I<MongoDB> to I<Timeout> milliseconds.
+Setting this option to zero means no timeout, which is the default.
+
+=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. as an increasing integer
+number.
+
+=item B<Database> I<Database>
+
+=item B<User> I<User>
+
+=item B<Password> I<Password>
+
+Sets the information used when authenticating to a I<MongoDB> database. The
+fields are optional (in which case no authentication is attempted), but if you
+want to use authentication all three fields must be set.
+
+=back
+
+=head2 Plugin C<write_prometheus>
+
+The I<write_prometheus plugin> implements a tiny webserver that can be scraped
+using I<Prometheus>.
+
+B<Options:>
+
+=over 4
+
+=item B<Port> I<Port>
+
+Port the embedded webserver should listen on. Defaults to B<9103>.
+
+=item B<StalenessDelta> I<Seconds>
+
+Time in seconds after which I<Prometheus> considers a metric "stale" if it
+hasn't seen any update for it. This value must match the setting in Prometheus.
+It defaults to B<300> seconds (5 minutes), same as Prometheus.
+
+B<Background:>
+
+I<Prometheus> has a global setting, C<StalenessDelta>, which controls after
+which time a metric without updates is considered "stale". This setting
+effectively puts an upper limit on the interval in which metrics are reported.
+
+When the I<write_prometheus plugin> encounters a metric with an interval
+exceeding this limit, it will inform you, the user, and provide the metric to
+I<Prometheus> B<without> a timestamp. That causes I<Prometheus> to consider the
+metric "fresh" each time it is scraped, with the time of the scrape being
+considered the time of the update. The result is that there appear more
+datapoints in I<Prometheus> than were actually created, but at least the metric
+doesn't disappear periodically.
+
+=back
+
+=head2 Plugin C<write_http>
+
+This output plugin submits values to an HTTP server using POST requests and
+encoding metrics with JSON or using the C<PUTVAL> command described in
+L<collectd-unixsock(5)>.
+
+Synopsis:
+
+ <Plugin "write_http">
+ <Node "example">
+ URL "http://example.com/post-collectd"
+ User "collectd"
+ Password "weCh3ik0"
+ Format JSON
+ </Node>
+ </Plugin>
+
+The plugin can send values to multiple HTTP servers by specifying one
+E<lt>B<Node>E<nbsp>I<Name>E<gt> block for each server. Within each B<Node>
+block, the following options are available:
+
+=over 4
+
+=item B<URL> I<URL>
+
+URL to which the values are submitted to. Mandatory.
+
+=item B<User> I<Username>
+
+Optional user name needed for authentication.
+
+=item B<Password> I<Password>
+
+Optional password needed for authentication.
+
+=item B<VerifyPeer> B<true>|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|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<CAPath> I<Directory>
+
+Directory holding one or more CA certificate files. You can use this if for
+some reason all the needed CA certificates aren't in the same file and can't be
+pointed to using the B<CACert> option. Requires C<libcurl> to be built against
+OpenSSL.
+
+=item B<ClientKey> I<File>
+
+File that holds the private key in PEM format to be used for certificate-based
+authentication.
+
+=item B<ClientCert> I<File>
+
+File that holds the SSL certificate to be used for certificate-based
+authentication.
+
+=item B<ClientKeyPass> I<Password>
+
+Password required to load the private key in B<ClientKey>.
+
+=item B<Header> I<Header>
+
+A HTTP header to add to the request. Multiple headers are added if this option is specified more than once. Example:
+
+ Header "X-Custom-Header: custom_value"
+
+=item B<SSLVersion> B<SSLv2>|B<SSLv3>|B<TLSv1>|B<TLSv1_0>|B<TLSv1_1>|B<TLSv1_2>
+
+Define which SSL protocol version must be used. By default C<libcurl> will
+attempt to figure out the remote SSL protocol version. See
+L<curl_easy_setopt(3)> for more details.
+
+=item B<Format> B<Command>|B<JSON>|B<KAIROSDB>
+
+Format of the output to generate. If set to B<Command>, will create output that
+is understood by the I<Exec> and I<UnixSock> plugins. When set to B<JSON>, will
+create output in the I<JavaScript Object Notation> (JSON). When set to KAIROSDB
+, will create output in the KairosDB format.
+
+Defaults to B<Command>.
+
+=item B<Metrics> B<true>|B<false>
+
+Controls whether I<metrics> are POSTed to this location. Defaults to B<true>.
+
+=item B<Notifications> B<false>|B<true>
+
+Controls whether I<notifications> are POSTed to this location. Defaults to B<false>.
+
+=item B<StoreRates> B<true|false>
+
+If set to B<true>, convert counter values to rates. If set to B<false> (the
+default) counter values are stored as is, i.e. as an increasing integer number.
+
+=item B<BufferSize> I<Bytes>
+
+Sets the send buffer size to I<Bytes>. By increasing this buffer, less HTTP
+requests will be generated, but more metrics will be batched / metrics are
+cached for longer before being sent, introducing additional delay until they
+are available on the server side. I<Bytes> must be at least 1024 and cannot
+exceed the size of an C<int>, i.e. 2E<nbsp>GByte.
+Defaults to C<4096>.
+
+=item B<LowSpeedLimit> I<Bytes per Second>
+
+Sets the minimal transfer rate in I<Bytes per Second> below which the
+connection with the HTTP server will be considered too slow and aborted. All
+the data submitted over this connection will probably be lost. Defaults to 0,
+which means no minimum transfer rate is enforced.
+
+=item B<Timeout> I<Timeout>
+
+Sets the maximum time in milliseconds given for HTTP POST operations to
+complete. When this limit is reached, the POST operation will be aborted, and
+all the data in the current send buffer will probably be lost. Defaults to 0,
+which means the connection never times out.
+
+=item B<LogHttpError> B<false>|B<true>