Loads the plugin I<Plugin>. There must be at least one such line or B<collectd>
will be mostly useless.
+Starting with collectd 4.9, this may also be a block in which further options
+affecting the behavior of B<LoadPlugin> may be specified. The following
+options are allowed inside a B<LoadPlugin> block:
+
+ <LoadPlugin perl>
+ Globals true
+ </LoadPlugin>
+
+=over 4
+
+=item B<Globals> B<true|false>
+
+If enabled, collectd will export all global symbols of the plugin (and of all
+libraries loaded as dependencies of the plugin) and, thus, makes those symbols
+available for resolving unresolved symbols in subsequently loaded plugins if
+that is supported by your system. By default, this is disabled.
+
+This is useful (or possibly even required), e.E<nbsp>g., when loading a plugin
+that embeds some scripting language into the daemon (e.E<nbsp>g. the C<perl>
+or C<python> plugins). Scripting languages usually provide means to load
+extensions written in C. Those extensions require symbols provided by the
+interpreter, which is loaded as a dependency of the respective collectd
+plugin. See the documentation of those plugins (e.E<nbsp>g.,
+L<collectd-perl(5)> or L<collectd-python(5)>) for details.
+
+=back
+
=item B<Include> I<Path>
If I<Path> points to a file, includes that file. If I<Path> points to a
values lead to a higher system load produced by collectd, while higher values
lead to more coarse statistics.
+B<Warning:> You should set this once and then never touch it again. If you do,
+I<you will have to delete all your RRD files> or know some serious RRDtool
+magic! (Assuming you're using the I<RRDtool> or I<RRDCacheD> plugin.)
+
=item B<ReadThreads> I<Num>
Number of threads to start for reading plugins. The default value is B<5>, but
=item B<Hostname> I<Name>
Sets the hostname that identifies a host. If you omit this setting, the
-hostname will be determinded using the L<gethostname(2)> system call.
+hostname will be determined using the L<gethostname(2)> system call.
=item B<FQDNLookup> B<true|false>
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
+The following example will read the current value of AMD stock from Google's
finance page and dispatch the value to collectd.
<Plugin curl>
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<MeasureResponseTime> B<true>|B<false>
+
+Measure response time for the request. If this setting is enabled, B<Match>
+blocks (see below) are optional. Disabled by default.
+
=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.
+plugin below on how matches are defined. If the B<MeasureResponseTime> option
+is set to B<true>, B<Match> blocks are optional.
=back
In the B<Plugin> block, there may be one or more B<URL> blocks, each defining
a URL to be fetched via HTTP (using libcurl) and one or more B<Key> blocks.
-The B<Key> string argument must be in a path format, of which is used to collect
-a value from a JSON map object. If a B<Key> path element is that of a I<*> wildcard,
-the values for all keys will be collectd.
+The B<Key> string argument must be in a path format, which is used to collect a
+value from a JSON map object. If a path element of B<Key> is the
+I<*>E<nbsp>wildcard, the values for all keys will be collectd.
The following options are valid within B<URL> 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.
+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
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
+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
Select partitions based on the filesystem type.
-=item B<IgnoreSelected> I<true>|I<false>
+=item B<IgnoreSelected> B<true>|B<false>
Invert the selection: If set to true, all partitions B<except> the ones that
match any one of the criteria are collected. By default only selected
partitions are collected if a selection is made. If no selection is configured
at all, B<all> partitions are selected.
-=item B<ReportByDevice> I<true>|I<false>
+=item B<ReportByDevice> B<true>|B<false>
Report using the device name rather than the mountpoint. i.e. with this I<false>,
(the default), it will report a disk as "root", but with it I<true>, it will be
"sda1" (or whichever).
+=item B<ReportReserved> B<true>|B<false>
+
+When enabled, the blocks reserved for root are reported separately. When
+disabled (the default for backwards compatibility reasons) the reserved space
+will be included in the "free" space.
+
+When disabled, the "df" type will be used to store "free" and "used" space. The
+mount point or disk name (see option B<ReportByDevice>) is used as type
+instance in this case (again: backwards compatibility).
+
+When enabled, the type "df_complex" is used and three files are created. The
+mount point or disk name is used as plugin instance and the type instance is
+set to "free", "reserved" and "used" as appropriate.
+
+Enabling this option is recommended.
+
+=item B<ReportInodes> B<true>|B<false>
+
+Enables or disables reporting of free, reserved and used inodes. Defaults to
+inode collection being disabled.
+
+Enable this option if inodes are a scarce resource for you, usually because
+many small files are stored on the disk. This is a usual scenario for mail
+transfer agents and web caches.
+
=back
=head2 Plugin C<disk>
=item B<Interface> I<Interface>
-The dns plugin uses B<libpcap> to capture dns traffic and analyses it. This
+The dns plugin uses B<libpcap> to capture dns traffic and analyzes it. This
option sets the interface that should be used. If this option is not set, or
set to "any", the plugin will try to get packets from B<all> interfaces. This
may not work on certain platforms, such as MacE<nbsp>OSE<nbsp>X.
=back
+=head2 Plugin C<netapp>
+
+The netapp plugin can collect various performance and capacity information
+from a NetApp filer using the NetApp API.
+
+Please note that NetApp has a wide line of products and a lot of different
+software versions for each of these products. This plugin was developed for a
+NetApp FAS3040 running OnTap 7.2.3P8 and tested on FAS2050 7.3.1.1L1,
+FAS3140 7.2.5.1 and FAS3020 7.2.4P9. It I<should> work for most combinations of
+model and software version but it is very hard to test this.
+If you have used this plugin with other models and/or software version, feel
+free to send us a mail to tell us about the results, even if it's just a short
+"It works".
+
+To collect these data collectd will log in to the NetApp via HTTP(S) and HTTP
+basic authentication.
+
+B<Do not use a regular user for this!> Create a special collectd user with just
+the minimum of capabilities needed. The user only needs the "login-http-admin"
+capability as well as a few more depending on which data will be collected.
+Required capabilities are documented below.
+
+=head3 Synopsis
+
+ <Plugin "netapp">
+ <Host "netapp1.example.com">
+ Protocol "https"
+ Address "10.0.0.1"
+ Port 443
+ User "username"
+ Password "aef4Aebe"
+ Interval 30
+
+ <WAFL>
+ Interval 30
+ GetNameCache true
+ GetDirCache true
+ GetBufferCache true
+ GetInodeCache true
+ </WAFL>
+
+ <Disks>
+ Interval 30
+ GetBusy true
+ </Disks>
+
+ <VolumePerf>
+ Interval 30
+ GetIO "volume0"
+ IgnoreSelectedIO false
+ GetOps "volume0"
+ IgnoreSelectedOps false
+ GetLatency "volume0"
+ IgnoreSelectedLatency false
+ </VolumePerf>
+
+ <VolumeUsage>
+ Interval 30
+ GetCapacity "vol0"
+ GetCapacity "vol1"
+ IgnoreSelectedCapacity false
+ GetSnapshot "vol1"
+ GetSnapshot "vol3"
+ IgnoreSelectedSnapshot false
+ </VolumeUsage>
+
+ <System>
+ Interval 30
+ GetCPULoad true
+ GetInterfaces true
+ GetDiskOps true
+ GetDiskIO true
+ </System>
+ </Host>
+ </Plugin>
+
+The netapp plugin accepts the following configuration options:
+
+=over 4
+
+=item B<Host> I<Name>
+
+A host block defines one NetApp filer. It will appear in collectd with the name
+you specify here which does not have to be its real name nor its hostname.
+
+=item B<Protocol> B<httpd>|B<http>
+
+The protocol collectd will use to query this host.
+
+Optional
+
+Type: string
+
+Default: https
+
+Valid options: http, https
+
+=item B<Address> I<Address>
+
+The hostname or IP address of the host.
+
+Optional
+
+Type: string
+
+Default: The "host" block's name.
+
+=item B<Port> I<Port>
+
+The TCP port to connect to on the host.
+
+Optional
+
+Type: integer
+
+Default: 80 for protocol "http", 443 for protocol "https"
+
+=item B<User> I<User>
+
+=item B<Password> I<Password>
+
+The username and password to use to login to the NetApp.
+
+Mandatory
+
+Type: string
+
+=item B<Interval> I<Interval>
+
+B<TODO>
+
+=back
+
+The following options decide what kind of data will be collected. You can
+either use them as a block and fine tune various parameters inside this block,
+use them as a single statement to just accept all default values, or omit it to
+not collect any data.
+
+The following options are valid inside all blocks:
+
+=over 4
+
+=item B<Interval> I<Seconds>
+
+Collect the respective statistics every I<Seconds> seconds. Defaults to the
+host specific setting.
+
+=back
+
+=head3 The System block
+
+This will collect various performance data about the whole system.
+
+B<Note:> To get this data the collectd user needs the
+"api-perf-object-get-instances" capability.
+
+=over 4
+
+=item B<Interval> I<Seconds>
+
+Collect disk statistics every I<Seconds> seconds.
+
+=item B<GetCPULoad> B<true>|B<false>
+
+If you set this option to true the current CPU usage will be read. This will be
+the average usage between all CPUs in your NetApp without any information about
+individual CPUs.
+
+B<Note:> These are the same values that the NetApp CLI command "sysstat"
+returns in the "CPU" field.
+
+Optional
+
+Type: boolean
+
+Default: true
+
+Result: Two value lists of type "cpu", and type instances "idle" and "system".
+
+=item B<GetInterfaces> B<true>|B<false>
+
+If you set this option to true the current traffic of the network interfaces
+will be read. This will be the total traffic over all interfaces of your NetApp
+without any information about individual interfaces.
+
+B<Note:> This is the same values that the NetApp CLI command "sysstat" returns
+in the "Net kB/s" field.
+
+B<Or is it?>
+
+Optional
+
+Type: boolean
+
+Default: true
+
+Result: One value list of type "if_octects".
+
+=item B<GetDiskIO> B<true>|B<false>
+
+If you set this option to true the current IO throughput will be read. This
+will be the total IO of your NetApp without any information about individual
+disks, volumes or aggregates.
+
+B<Note:> This is the same values that the NetApp CLI command "sysstat" returns
+in the "DiskE<nbsp>kB/s" field.
+
+Optional
+
+Type: boolean
+
+Default: true
+
+Result: One value list of type "disk_octets".
+
+=item B<GetDiskOps> B<true>|B<false>
+
+If you set this option to true the current number of HTTP, NFS, CIFS, FCP,
+iSCSI, etc. operations will be read. This will be the total number of
+operations on your NetApp without any information about individual volumes or
+aggregates.
+
+B<Note:> These are the same values that the NetApp CLI command "sysstat"
+returns in the "NFS", "CIFS", "HTTP", "FCP" and "iSCSI" fields.
+
+Optional
+
+Type: boolean
+
+Default: true
+
+Result: A variable number of value lists of type "disk_ops_complex". Each type
+of operation will result in one value list with the name of the operation as
+type instance.
+
+=back
+
+=head3 The WAFL block
+
+This will collect various performance data about the WAFL file system. At the
+moment this just means cache performance.
+
+B<Note:> To get this data the collectd user needs the
+"api-perf-object-get-instances" capability.
+
+B<Note:> The interface to get these values is classified as "Diagnostics" by
+NetApp. This means that it is not guaranteed to be stable even between minor
+releases.
+
+=over 4
+
+=item B<Interval> I<Seconds>
+
+Collect disk statistics every I<Seconds> seconds.
+
+=item B<GetNameCache> B<true>|B<false>
+
+Optional
+
+Type: boolean
+
+Default: true
+
+Result: One value list of type "cache_ratio" and type instance
+"name_cache_hit".
+
+=item B<GetDirCache> B<true>|B<false>
+
+Optional
+
+Type: boolean
+
+Default: true
+
+Result: One value list of type "cache_ratio" and type instance "find_dir_hit".
+
+=item B<GetInodeCache> B<true>|B<false>
+
+Optional
+
+Type: boolean
+
+Default: true
+
+Result: One value list of type "cache_ratio" and type instance
+"inode_cache_hit".
+
+=item B<GetBufferCache> B<true>|B<false>
+
+B<Note:> This is the same value that the NetApp CLI command "sysstat" returns
+in the "Cache hit" field.
+
+Optional
+
+Type: boolean
+
+Default: true
+
+Result: One value list of type "cache_ratio" and type instance "buf_hash_hit".
+
+=back
+
+=head3 The Disks block
+
+This will collect performance data about the individual disks in the NetApp.
+
+B<Note:> To get this data the collectd user needs the
+"api-perf-object-get-instances" capability.
+
+=over 4
+
+=item B<Interval> I<Seconds>
+
+Collect disk statistics every I<Seconds> seconds.
+
+=item B<GetBusy> B<true>|B<false>
+
+If you set this option to true the busy time of all disks will be calculated
+and the value of the busiest disk in the system will be written.
+
+B<Note:> This is the same values that the NetApp CLI command "sysstat" returns
+in the "Disk util" field. Probably.
+
+Optional
+
+Type: boolean
+
+Default: true
+
+Result: One value list of type "percent" and type instance "disk_busy".
+
+=back
+
+=head3 The VolumePerf block
+
+This will collect various performance data about the individual volumes.
+
+You can select which data to collect about which volume using the following
+options. They follow the standard ignorelist semantic.
+
+B<Note:> To get this data the collectd user needs the
+I<api-perf-object-get-instances> capability.
+
+=over 4
+
+=item B<Interval> I<Seconds>
+
+Collect volume performance data every I<Seconds> seconds.
+
+=item B<GetIO> I<Volume>
+
+=item B<GetOps> I<Volume>
+
+=item B<GetLatency> I<Volume>
+
+Select the given volume for IO, operations or latency statistics collection.
+The argument is the name of the volume without the C</vol/> prefix.
+
+Since the standard ignorelist functionality is used here, you can use a string
+starting and ending with a slash to specify regular expression matching: To
+match the volumes "vol0", "vol2" and "vol7", you can use this regular
+expression:
+
+ GetIO "/^vol[027]$/"
+
+If no regular expression is specified, an exact match is required. Both,
+regular and exact matching are case sensitive.
+
+If no volume was specified at all for either of the three options, that data
+will be collected for all available volumes.
+
+=item B<IgnoreSelectedIO> B<true>|B<false>
+
+=item B<IgnoreSelectedOps> B<true>|B<false>
+
+=item B<IgnoreSelectedLatency> B<true>|B<false>
+
+When set to B<true>, the volumes selected for IO, operations or latency
+statistics collection will be ignored and the data will be collected for all
+other volumes.
+
+When set to B<false>, data will only be collected for the specified volumes and
+all other volumes will be ignored.
+
+If no volumes have been specified with the above B<Get*> options, all volumes
+will be collected regardless of the B<IgnoreSelected*> option.
+
+Defaults to B<false>
+
+=back
+
+=head3 The VolumeUsage block
+
+This will collect capacity data about the individual volumes.
+
+B<Note:> To get this data the collectd user needs the I<api-volume-list-info>
+capability.
+
+=over 4
+
+=item B<Interval> I<Seconds>
+
+Collect volume usage statistics every I<Seconds> seconds.
+
+=item B<GetCapacity> I<VolumeName>
+
+The current capacity of the volume will be collected. This will result in two
+to four value lists, depending on the configuration of the volume. All data
+sources are of type "df_complex" with the name of the volume as
+plugin_instance.
+
+There will be type_instances "used" and "free" for the number of used and
+available bytes on the volume. If the volume has some space reserved for
+snapshots, a type_instance "snap_reserved" will be available. If the volume
+has SIS enabled, a type_instance "sis_saved" will be available. This is the
+number of bytes saved by the SIS feature.
+
+B<Note:> The current NetApp API has a bug that results in this value being
+reported as a 32E<nbsp>bit number. This plugin tries to guess the correct
+number which works most of the time. If you see strange values here, bug
+NetApp support to fix this.
+
+Repeat this option to specify multiple volumes.
+
+=item B<IgnoreSelectedCapacity> B<true>|B<false>
+
+Specify whether to collect only the volumes selected by the B<GetCapacity>
+option or to ignore those volumes. B<IgnoreSelectedCapacity> defaults to
+B<false>. However, if no B<GetCapacity> option is specified at all, all
+capacities will be selected anyway.
+
+=item B<GetSnapshot> I<VolumeName>
+
+Select volumes from which to collect snapshot information.
+
+Usually, the space used for snapshots is included in the space reported as
+"used". If snapshot information is collected as well, the space used for
+snapshots is subtracted from the used space.
+
+To make things even more interesting, it is possible to reserve space to be
+used for snapshots. If the space required for snapshots is less than that
+reserved space, there is "reserved free" and "reserved used" space in addition
+to "free" and "used". If the space required for snapshots exceeds the reserved
+space, that part allocated in the normal space is subtracted from the "used"
+space again.
+
+Repeat this option to specify multiple volumes.
+
+=item B<IgnoreSelectedSnapshot>
+
+Specify whether to collect only the volumes selected by the B<GetSnapshot>
+option or to ignore those volumes. B<IgnoreSelectedSnapshot> defaults to
+B<false>. However, if no B<GetSnapshot> option is specified at all, all
+capacities will be selected anyway.
+
+=back
+
=head2 Plugin C<netlink>
The C<netlink> plugin uses a netlink socket to query the Linux kernel about
=item B<IgnoreSelected>
-The behaviour is the same as with all other similar plugins: If nothing is
+The behavior 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 inverted, i.E<nbsp>e. the
The Network plugin sends data to a remote instance of collectd, receives data
from a remote instance, or both at the same time. Data which has been received
-from the network is usually not transmitted again, but this can be actived, see
+from the network is usually not transmitted again, but this can be activated, see
the B<Forward> option below.
The default IPv6 multicast group is C<ff18::efc0:4a42>. The default IPv4
1800 seconds, but setting this to 86400 seconds (one day) will not do much harm
either.
+=item B<ReportStats> B<true>|B<false>
+
+The network plugin cannot only receive and send statistics, it can also create
+statistics about itself. Collected data included the number of received and
+sent octets and packets, the length of the receive queue and the number of
+values handled. When set to B<true>, the I<Network plugin> will make these
+statistics available. Defaults to B<false>.
+
=back
=head2 Plugin C<nginx>
=item B<ReverseLookups> B<true>|B<false>
-Sets wether or not to perform reverse lookups on peers. Since the name or
+Sets whether or not to perform reverse lookups on peers. Since the name or
IP-address may be used in a filename it is recommended to disable reverse
lookups. The default is to do reverse lookups to preserve backwards
compatibility, though.
Specifies the location of the status file.
+=item B<ImprovedNamingSchema> B<true>|B<false>
+
+When enabled, the filename of the status file will be used as plugin instance
+and the client's "common name" will be used as type instance. This is required
+when reading multiple status files. Enabling this option is recommended, but to
+maintain backwards compatibility this option is disabled by default.
+
+=item B<Compression> B<true>|B<false>
+
+Sets whether or not statistics about the compression used by OpenVPN should be
+collected. This information is only available in I<single> mode. Enabled by
+default.
+
=back
=head2 Plugin C<oracle>
Sets the Time-To-Live of generated ICMP packets.
+=item B<SourceAddress> I<host>
+
+Sets the source address to use. I<host> may either be a numerical network
+address or a network hostname.
+
+=item B<Device> I<name>
+
+Sets the outgoing network device to be used. I<name> has to specify an
+interface name (e.E<nbsp>g. C<eth0>). This might not be supported by all
+operating systems.
+
+=item B<MaxMissed> I<Packets>
+
+Trigger a DNS resolv after the host has not replied to I<Packets> packets. This
+enables the use of dynamic DNS services (like dyndns.org) with the ping plugin.
+
+Default: B<-1> (disabled)
+
=back
=head2 Plugin C<postgresql>
Select more detailed statistics of processes matching this name. The statistics
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.
+io data (where available) and minor and major pagefaults.
=item B<ProcessMatch> I<name> I<regex>
=back
+=head2 Plugin C<python>
+
+This plugin embeds a Python-interpreter into collectd and provides an interface
+to collectd's plugin system. See L<collectd-python(5)> for its documentation.
+
+=head2 Plugin C<routeros>
+
+The C<routeros> plugin connects to a device running I<RouterOS>, the
+Linux-based operating system for routers by I<MikroTik>. The plugin uses
+I<librouteros> to connect and reads information about the interfaces and
+wireless connections of the device. The configuration supports querying
+multiple routers:
+
+ <Plugin "routeros">
+ <Router>
+ Host "router0.example.com"
+ User "collectd"
+ Password "secr3t"
+ CollectInterface true
+ </Router>
+ <Router>
+ Host "router1.example.com"
+ User "collectd"
+ Password "5ecret"
+ CollectInterface true
+ CollectRegistrationTable true
+ </Router>
+ </Plugin>
+
+As you can see above, the configuration of the I<routeros> plugin consists of
+one or more B<E<lt>RouterE<gt>> blocks. Within each block, the following
+options are understood:
+
+=over 4
+
+=item B<Host> I<Host>
+
+Hostname or IP-address of the router to connect to.
+
+=item B<Port> I<Port>
+
+Port name or port number used when connecting. If left unspecified, the default
+will be chosen by I<librouteros>, currently "8728". This option expects a
+string argument, even when a numeric port number is given.
+
+=item B<User> I<User>
+
+Use the user name I<User> to authenticate. Defaults to "admin".
+
+=item B<Password> I<Password>
+
+Set the password used to authenticate.
+
+=item B<CollectInterface> B<true>|B<false>
+
+When set to B<true>, interface statistics will be collected for all interfaces
+present on the device. Defaults to B<false>.
+
+=item B<CollectRegistrationTable> B<true>|B<false>
+
+When set to B<true>, information about wireless LAN connections will be
+collected. Defaults to B<false>.
+
+=back
+
=head2 Plugin C<rrdcached>
The C<rrdcached> plugin uses the RRDtool accelerator daemon, L<rrdcached(1)>,
=item B<CounterSet>
-The matched number is a counter. Simply sets the internal counter to this
-value.
+=item B<DeriveSet>
+
+=item B<AbsoluteSet>
+
+The matched number is a counter. Simply I<sets> the internal counter to this
+value. Variants exist for C<COUNTER>, C<DERIVE>, and C<ABSOLUTE> data sources.
=item B<CounterAdd>
-Add the matched value to the internal counter.
+=item B<DeriveAdd>
+
+Add the matched value to the internal counter. In case of B<DeriveAdd>, the
+matched number may be negative, which will effectively subtract from the
+internal counter.
=item B<CounterInc>
-Increase the internal counter by one. This B<DSType> is the only one that does
-not use the matched subexpression, but simply counts the number of matched
+=item B<DeriveInc>
+
+Increase the internal counter by one. These B<DSType> are the only ones that do
+not use the matched subexpression, but simply count the number of matched
lines. Thus, you may use a regular expression without submatch in this case.
=back
As you'd expect the B<Gauge*> types interpret the submatch as a floating point
-number, using L<strtod(3)>. The B<CounterSet> and B<CounterAdd> interpret the
-submatch as an integer using L<strtoll(3)>. B<CounterInc> does not use the
-submatch at all and it may be omitted in this case.
+number, using L<strtod(3)>. The B<Counter*> and B<AbsoluteSet> types interpret
+the submatch as an unsigned integer using L<strtoull(3)>. The B<Derive*> types
+interpret the submatch as a signed integer using L<strtoll(3)>. B<CounterInc>
+and B<DeriveInc> do not use the submatch at all and it may be omitted in this
+case.
=item B<Type> I<Type>
=head2 Plugin C<tokyotyrant>
-The C<tokyotyrant plugin> connects to a TokyoTyrant server and collects a
+The C<tokyotyrant plugin> connects to a TokyoTyrant server and collects a
couple metrics: number of records, and database size on disk.
=over 4
=back
-=head2 Built-in targets
+=head2 Built-in targets
The following targets are built into the core daemon and therefore need no
plugins to be loaded:
usually), the graph will be empty (NAN) for a long time. People may not
understand why.
+=item B<hashed>
+
+Calculates a hash value of the host name and matches values according to that
+hash value. This makes it possible to divide all hosts into groups and match
+only values that are in a specific group. The intended use is in load
+balancing, where you want to handle only part of all data and leave the rest
+for other servers.
+
+The hashing function used tries to distribute the hosts evenly. First, it
+calculates a 32E<nbsp>bit hash value using the characters of the hostname:
+
+ hash_value = 0;
+ for (i = 0; host[i] != 0; i++)
+ hash_value = (hash_value * 251) + host[i];
+
+The constant 251 is a prime number which is supposed to make this hash value
+more random. The code then checks the group for this host according to the
+I<Total> and I<Match> arguments:
+
+ if ((hash_value % Total) == Match)
+ matches;
+ else
+ does not match;
+
+Please note that when you set I<Total> to two (i.E<nbsp>e. you have only two
+groups), then the least significant bit of the hash value will be the XOR of
+all least significant bits in the host name. One consequence is that when you
+have two hosts, "server0.example.com" and "server1.example.com", where the host
+name differs in one digit only and the digits differ by one, those hosts will
+never end up in the same group.
+
+Available options:
+
+=over 4
+
+=item B<Match> I<Match> I<Total>
+
+Divide the data into I<Total> groups and match all hosts in group I<Match> as
+described above. The groups are numbered from zero, i.E<nbsp>e. I<Match> must
+be smaller than I<Total>. I<Total> must be at least one, although only values
+greater than one really do make any sense.
+
+You can repeat this option to match multiple groups, for example:
+
+ Match 3 7
+ Match 5 7
+
+The above config will divide the data into seven groups and match groups three
+and five. One use would be to keep every value on two hosts so that if one
+fails the missing data can later be reconstructed from the second host.
+
+=back
+
+Example:
+
+ # Operate on the pre-cache chain, so that ignored values are not even in the
+ # global cache.
+ <Chain "PreCache">
+ <Rule>
+ <Match "hashed">
+ # Divide all received hosts in seven groups and accept all hosts in
+ # group three.
+ Match 3 7
+ </Match>
+ # If matched: Return and continue.
+ Target "return"
+ </Rule>
+ # If not matched: Return and stop.
+ Target "stop"
+ </Chain>
+
=back
=head2 Available targets
projects / collectd.git / blobdiff