1COLLECTD-SNMP(5)                   collectd                   COLLECTD-SNMP(5)
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NAME

6       collectd-snmp - Documentation of collectd's "snmp plugin"
7

SYNOPSIS

9         LoadPlugin snmp
10         # ...
11         <Plugin snmp>
12           <Data "powerplus_voltge_input">
13             Type "voltage"
14             Table false
15             Instance "input_line1"
16             Scale 0.1
17             Values "SNMPv2-SMI::enterprises.6050.5.4.1.1.2.1"
18           </Data>
19           <Data "hr_users">
20             Type "users"
21             Table false
22             Instance ""
23             Shift -1
24             Values "HOST-RESOURCES-MIB::hrSystemNumUsers.0"
25           </Data>
26           <Data "std_traffic">
27             Type "if_octets"
28             Table true
29             Instance "IF-MIB::ifDescr"
30             Values "IF-MIB::ifInOctets" "IF-MIB::ifOutOctets"
31           </Data>
32
33           <Host "some.switch.mydomain.org">
34             Address "192.168.0.2"
35             Version 1
36             Community "community_string"
37             Collect "std_traffic"
38             Interval 120
39           </Host>
40           <Host "some.server.mydomain.org">
41             Address "192.168.0.42"
42             Version 2
43             Community "another_string"
44             Collect "std_traffic" "hr_users"
45           </Host>
46           <Host "some.ups.mydomain.org">
47             Address "192.168.0.3"
48             Version 1
49             Community "more_communities"
50             Collect "powerplus_voltge_input"
51             Interval 300
52           </Host>
53         </Plugin>
54

DESCRIPTION

56       The "snmp plugin" queries other hosts using SNMP, the simple network
57       management protocol, and translates the value it receives to collectd's
58       internal format and dispatches them. Depending on the write plugins you
59       have loaded they may be written to disk or submitted to another
60       instance or whatever you configured.
61
62       Because querying a host via SNMP may produce a timeout multiple threads
63       are used to query hosts in parallel. Depending on the number of hosts
64       between one and ten threads are used.
65

CONFIGURATION

67       Since the aim of the "snmp plugin" is to provide a generic interface to
68       SNMP, it's configuration is not trivial and may take some time.
69
70       Since the "Net-SNMP" library is used you can use all the environment
71       variables that are interpreted by that package. See snmpcmd(1) for more
72       details.
73
74       There are two types of blocks that can be contained in the
75       "<Plugin snmp>" block: Data and Host:
76
77   The Data block
78       The Data block defines a list of values or a table of values that are
79       to be queried. The following options can be set:
80
81       Type type
82           collectd's type that is to be used, e. g. "if_octets" for interface
83           traffic or "users" for a user count. The types are read from the
84           TypesDB (see collectd.conf(5)), so you may want to check for which
85           types are defined. See types.db(5) for a description of the format
86           of this file.
87
88       Table true|false
89           Define if this is a single list of values or a table of values. The
90           difference is the following:
91
92           When Table is set to false, the OIDs given to Values (see below)
93           are queried using the "GET" SNMP command (see snmpget(1)) and
94           transmitted to collectd. One value list is dispatched and,
95           eventually, one file will be written.
96
97           When Table is set to true, the OIDs given to Values (see below) are
98           queried using the "GETNEXT" SNMP command until the subtree is left.
99           After all the lists (think: all columns of the table) have been
100           read several values sets will be dispatches and, eventually,
101           several files will be written. If you configure a Type (see above)
102           which needs more than one data source (for example "if_octets"
103           which needs "rx" and "tx") you will need to specify more than one
104           (two, in the example case) OIDs with the Values option. This has
105           nothing to do with the Table setting.
106
107           For example, if you want to query the number of users on a system,
108           you can use "HOST-RESOURCES-MIB::hrSystemNumUsers.0". This is one
109           value and belongs to one value list, therefore Table must be set to
110           false. Please note that, in this case, you have to include the
111           sequence number (zero in this case) in the OID.
112
113           Counter example: If you want to query the interface table provided
114           by the "IF-MIB", e. g. the bytes transmitted. There are potentially
115           many interfaces, so you will want to set Table to true. Because the
116           "if_octets" type needs two values, received and transmitted bytes,
117           you need to specify two OIDs in the Values setting, in this case
118           likely "IF-MIB::ifHCInOctets" and "IF-MIB::ifHCOutOctets". But,
119           this is because of the Type setting, not the Table setting.
120
121           Since the semantic of Instance and Values depends on this setting
122           you need to set it before setting them. Doing vice verse will
123           result in undefined behavior.
124
125       Instance Instance
126           Sets the type-instance of the values that are dispatched. The
127           meaning of this setting depends on whether Table is set to true or
128           false:
129
130           If Table is set to true, Instance is interpreted as an SNMP-prefix
131           that will return a list of values. Those values are then used as
132           the actual type-instance. An example would be the "IF-MIB::ifDescr"
133           subtree.  variables(5) from the SNMP distribution describes the
134           format of OIDs.
135
136           If Table is set to true and Instance is omitted, then "SUBID" will
137           be used as the instance.
138
139           If Table is set to false the actual string configured for Instance
140           is copied into the value-list. In this case Instance may be empty,
141           i. e.  "".
142
143       InstancePrefix String
144           If Table is set to true, you may feel the need to add something to
145           the instance of the files. If set, String is prepended to the
146           instance as determined by querying the agent. When Table is set to
147           false this option has no effect.
148
149           The "UPS-MIB" is an example where you need this setting: It has
150           voltages of the inlets, outlets and the battery of an UPS. However,
151           it doesn't provide a descriptive column for these voltages. In this
152           case having 1, 2, ... as instances is not enough, because the inlet
153           voltages and outlet voltages may both have the subids 1, 2, ... You
154           can use this setting to distinguish between the different voltages.
155
156       Values OID [OID ...]
157           Configures the values to be queried from the SNMP host. The meaning
158           slightly changes with the Table setting. variables(5) from the SNMP
159           distribution describes the format of OIDs.
160
161           If Table is set to true, each OID must be the prefix of all the
162           values to query, e. g. "IF-MIB::ifInOctets" for all the counters of
163           incoming traffic. This subtree is walked (using "GETNEXT") until a
164           value from outside the subtree is returned.
165
166           If Table is set to false, each OID must be the OID of exactly one
167           value, e. g. "IF-MIB::ifInOctets.3" for the third counter of
168           incoming traffic.
169
170       Scale Value
171           The gauge-values returned by the SNMP-agent are multiplied by
172           Value.  This is useful when values are transfered as a fixed point
173           real number. For example, thermometers may transfer 243 but
174           actually mean 24.3, so you can specify a scale value of 0.1 to
175           correct this. The default value is, of course, 1.0.
176
177           This value is not applied to counter-values.
178
179       Shift Value
180           Value is added to gauge-values returned by the SNMP-agent after
181           they have been multiplied by any Scale value. If, for example, a
182           thermometer returns degrees Kelvin you could specify a shift of
183           273.15 here to store values in degrees Celsius. The default value
184           is, of course, 0.0.
185
186           This value is not applied to counter-values.
187
188   The Host block
189       The Host block defines which hosts to query, which SNMP community and
190       version to use and which of the defined Data to query.
191
192       The argument passed to the Host block is used as the hostname in the
193       data stored by collectd.
194
195       Address IP-Address|Hostname
196           Set the address to connect to.
197
198       Version 1|2
199           Set the SNMP version to use. When giving 2 version "2c" is actually
200           used.  Version 3 is not supported by this plugin.
201
202       Community Community
203           Pass Community to the host.
204
205       Collect Data [Data ...]
206           Defines which values to collect. Data refers to one of the Data
207           block above. Since the config file is read top-down you need to
208           define the data before using it here.
209
210       Interval Seconds
211           Collect data from this host every Seconds seconds. This option is
212           meant for devices with not much CPU power, e. g. network equipment
213           such as switches, embedded devices, rack monitoring systems and so
214           on. Since the Step of generated RRD files depends on this setting
215           it's wise to select a reasonable value once and never change it.
216

SEE ALSO

218       collectd(1), collectd.conf(5), snmpget(1), snmpgetnext(1),
219       variables(5), unix(7)
220

AUTHOR

222       Florian Forster <octo@verplant.org>
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2264.9.5                             2011-03-26                  COLLECTD-SNMP(5)
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