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Under GNU General Public License
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COLLECTD-SNMP(5) collectd COLLECTD-SNMP(5)
NAME
collectd-snmp - Documentation of collectd's "snmp plugin"
SYNOPSIS
LoadPlugin snmp
# ...
<Plugin snmp>
<Data "powerplus_voltge_input">
Type "voltage"
Table false
Instance "input_line1"
Scale 0.1
Values "SNMPv2-SMI::enterprises.6050.5.4.1.1.2.1"
</Data>
<Data "hr_users">
Type "users"
Table false
Instance ""
Shift -1
Values "HOST-RESOURCES-MIB::hrSystemNumUsers.0"
</Data>
<Data "std_traffic">
Type "if_octets"
Table true
Instance "IF-MIB::ifDescr"
Values "IF-MIB::ifInOctets" "IF-MIB::ifOutOctets"
</Data>
<Host "some.switch.mydomain.org">
Address "192.168.0.2"
Version 1
Community "community_string"
Collect "std_traffic"
Interval 120
</Host>
<Host "some.server.mydomain.org">
Address "192.168.0.42"
Version 2
Community "another_string"
Collect "std_traffic" "hr_users"
</Host>
<Host "some.ups.mydomain.org">
Address "192.168.0.3"
Version 1
Community "more_communities"
Collect "powerplus_voltge_input"
Interval 300
</Host>
</Plugin>
DESCRIPTION
The "snmp plugin" queries other hosts using SNMP, the simple network management protocol,
and translates the value it receives to collectd's internal format and dispatches them.
Depending on the write plugins you have loaded they may be written to disk or submitted to
another instance or whatever you configured.
Because querying a host via SNMP may produce a timeout multiple threads are used to query
hosts in parallel. Depending on the number of hosts between one and ten threads are used.
CONFIGURATION
Since the aim of the "snmp plugin" is to provide a generic interface to SNMP, it's
configuration is not trivial and may take some time.
Since the "Net-SNMP" library is used you can use all the environment variables that are
interpreted by that package. See snmpcmd(1) for more details.
There are two types of blocks that can be contained in the "<Plugin snmp>" block: Data and
Host:
The Data block
The Data block defines a list of values or a table of values that are to be queried. The
following options can be set:
Type type
collectd's type that is to be used, e. g. "if_octets" for interface traffic or "users"
for a user count. The types are read from the TypesDB (see collectd.conf(5)), so you
may want to check for which types are defined. See types.db(5) for a description of
the format of this file.
Table true|false
Define if this is a single list of values or a table of values. The difference is the
following:
When Table is set to false, the OIDs given to Values (see below) are queried using the
"GET" SNMP command (see snmpget(1)) and transmitted to collectd. One value list is
dispatched and, eventually, one file will be written.
When Table is set to true, the OIDs given to Values (see below) are queried using the
"GETNEXT" SNMP command until the subtree is left. After all the lists (think: all
columns of the table) have been read several values sets will be dispatches and,
eventually, several files will be written. If you configure a Type (see above) which
needs more than one data source (for example "if_octets" which needs "rx" and "tx")
you will need to specify more than one (two, in the example case) OIDs with the Values
option. This has nothing to do with the Table setting.
For example, if you want to query the number of users on a system, you can use
"HOST-RESOURCES-MIB::hrSystemNumUsers.0". This is one value and belongs to one value
list, therefore Table must be set to false. Please note that, in this case, you have
to include the sequence number (zero in this case) in the OID.
Counter example: If you want to query the interface table provided by the "IF-MIB",
e. g. the bytes transmitted. There are potentially many interfaces, so you will want
to set Table to true. Because the "if_octets" type needs two values, received and
transmitted bytes, you need to specify two OIDs in the Values setting, in this case
likely "IF-MIB::ifHCInOctets" and "IF-MIB::ifHCOutOctets". But, this is because of the
Type setting, not the Table setting.
Since the semantic of Instance and Values depends on this setting you need to set it
before setting them. Doing vice verse will result in undefined behavior.
Instance Instance
Sets the type-instance of the values that are dispatched. The meaning of this setting
depends on whether Table is set to true or false:
If Table is set to true, Instance is interpreted as an SNMP-prefix that will return a
list of values. Those values are then used as the actual type-instance. An example
would be the "IF-MIB::ifDescr" subtree. variables(5) from the SNMP distribution
describes the format of OIDs.
If Table is set to true and Instance is omitted, then "SUBID" will be used as the
instance.
If Table is set to false the actual string configured for Instance is copied into the
value-list. In this case Instance may be empty, i. e. "".
InstancePrefix String
If Table is set to true, you may feel the need to add something to the instance of the
files. If set, String is prepended to the instance as determined by querying the
agent. When Table is set to false this option has no effect.
The "UPS-MIB" is an example where you need this setting: It has voltages of the
inlets, outlets and the battery of an UPS. However, it doesn't provide a descriptive
column for these voltages. In this case having 1, 2, ... as instances is not enough,
because the inlet voltages and outlet voltages may both have the subids 1, 2, ... You
can use this setting to distinguish between the different voltages.
Values OID [OID ...]
Configures the values to be queried from the SNMP host. The meaning slightly changes
with the Table setting. variables(5) from the SNMP distribution describes the format
of OIDs.
If Table is set to true, each OID must be the prefix of all the values to query, e. g.
"IF-MIB::ifInOctets" for all the counters of incoming traffic. This subtree is walked
(using "GETNEXT") until a value from outside the subtree is returned.
If Table is set to false, each OID must be the OID of exactly one value, e. g.
"IF-MIB::ifInOctets.3" for the third counter of incoming traffic.
Scale Value
The gauge-values returned by the SNMP-agent are multiplied by Value. This is useful
when values are transfered as a fixed point real number. For example, thermometers may
transfer 243 but actually mean 24.3, so you can specify a scale value of 0.1 to
correct this. The default value is of course 1.0.
This value is not applied to counter-values.
Shift Value
Value is added to gauge-values returned by the SNMP-agent after they have been
multiplied by any Scale value. If, for example, a thermometer returns degrees Kelvin
you could specify a shift of 273.15 here to store values in degrees Celsius. The
default value is is course 0.0.
This value is not applied to counter-values.
The Host block
The Host block defines which hosts to query, which SNMP community and version to use and
which of the defined Data to query.
The argument passed to the Host block is used as the hostname in the data stored by
collectd.
Address IP-Address|Hostname
Set the address to connect to.
Version 1|2
Set the SNMP version to use. When giving 2 version "2c" is actually used. Version 3
is not supported by this plugin.
Community Community
Pass Community to the host.
Collect Data [Data ...]
Defines which values to collect. Data refers to one of the Data block above. Since the
config file is read top-down you need to define the data before using it here.
Interval Seconds
Collect data from this host every Seconds seconds. This value needs to be a multiple
of the global Interval setting and, if it is not, will be rounded down to one and a
warning is logged in this case. So if your global Interval is set to 10 and you
configure 25 here, it's rounded down to 20. By default the global Interval setting
will be used.
This option is meant for devices with not much CPU power, e. g. network equipment such
as switches, embedded devices, rack monitoring systems and so on. Since the Step of
generated RRD files depends on this setting it's wise to select a reasonable value
once and never change it.
SEE ALSO
collectd(1), collectd.conf(5), snmpget(1), snmpgetnext(1), variables(5), unix(7)
AUTHOR
Florian Forster <octo AT verplant.org>
4.4.2 2008-05-06 COLLECTD-SNMP(5)
Generated by $Id: phpMan.php,v 4.49 2006/02/26 13:18:18 chedong Exp $ Author: Che Dong
On Apache
Under GNU General Public License
2012-05-25 15:09 @38.107.179.239 Crawled by CCBot/1.0 (+http://www.commoncrawl.org/bot.html)