COLLECTD-SNMP(5) | collectd | COLLECTD-SNMP(5) |
collectd-snmp - Documentation of collectd's "snmp plugin"
LoadPlugin snmp # ... <Plugin snmp> <Data "powerplus_voltge_input"> Table false Type "voltage" TypeInstance "input_line1" Scale 0.1 Values "SNMPv2-SMI::enterprises.6050.5.4.1.1.2.1" </Data> <Data "hr_users"> Table false Type "users" Shift -1 Values "HOST-RESOURCES-MIB::hrSystemNumUsers.0" </Data> <Data "std_traffic"> Table true Type "if_octets" TypeInstanceOID "IF-MIB::ifDescr" #FilterOID "IF-MIB::ifOperStatus" #FilterValues "1", "2" Values "IF-MIB::ifInOctets" "IF-MIB::ifOutOctets" </Data> <Data "lancom_stations_total"> Type "counter" PluginInstance "stations_total" Table true Count true Values "SNMPv2-SMI::enterprises.2356.11.1.3.32.1.10" # SNMPv2-SMI::enterprises.lancom-systems.lcos.lcsStatus.lcsStatusWlan.lcsStatusWlanStationTableTable.lcsStatusWlanStationTableEntry.lcsStatusWlanStationTableEntryState </Data> <Data "lancom_stations_connected"> Type "counter" PluginInstance "stations_connected" Table true Count true Values "SNMPv2-SMI::enterprises.2356.11.1.3.32.1.10" # SNMPv2-SMI::enterprises.lancom-systems.lcos.lcsStatus.lcsStatusWlan.lcsStatusWlanStationTableTable.lcsStatusWlanStationTableEntry.lcsStatusWlanStationTableEntryState FilterOID "SNMPv2-SMI::enterprises.2356.11.1.3.32.1.10" FilterValues "3" # eConnected </Data> <Host "some.switch.mydomain.org"> Address "192.168.0.2" Version 1 Community "community_string" Collect "std_traffic" Interval 120 Timeout 10 Retries 1 </Host> <Host "some.server.mydomain.org"> Address "192.168.0.42" Version 2 Community "another_string" Collect "std_traffic" "hr_users" </Host> <Host "secure.router.mydomain.org"> Address "192.168.0.7:165" Version 3 SecurityLevel "authPriv" Username "cosmo" AuthProtocol "SHA" AuthPassphrase "setec_astronomy" PrivacyProtocol "AES" PrivacyPassphrase "too_many_secrets" Collect "std_traffic" </Host> <Host "some.ups.mydomain.org"> Address "tcp:192.168.0.3" Version 1 Community "more_communities" Collect "powerplus_voltge_input" Interval 300 Timeout 5 Retries 5 </Host> </Plugin>
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 the "complex reads" polling method is used. The ReadThreads parameter in the main configuration influences the number of parallel polling jobs which can be undertaken. If you expect timeouts or some polling to take a long time, you should increase this parameter. Note that other plugins also use the same threads.
Since the aim of the "snmp plugin" is to provide a generic interface to SNMP, its 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 defines a list of values or a table of values that are to be queried. The following options can be set:
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, TypeInstanceOID, PluginInstanceOID, HostOID and FilterOID (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, either (Count set to false) several value sets will be dispatched and, eventually, several files will be written, or (Count set to true) one single value will be dispatched. 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 and can't use the Count 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 versa will result in undefined behavior.
When Table is set to true and PluginInstanceOID is set then this option has no effect.
Defaults to an empty string.
When Table is set to true and TypeInstanceOID is set then this option has no effect.
Defaults to an empty string.
Prefix may be set for values with use of appropriate TypeInstancePrefix, PluginInstancePrefix and HostPrefix options.
When Table is set to false or Count is set to true, these options have no effect.
Defaults: When no one of these options is configured explicitly, TypeInstanceOID defaults to an empty string.
If set, String is preprended to values received by querying the agent.
When Table is set to false or Count is set to true, these options have 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.
The meaning of this setting depends on whether Table is set to true or false.
If Table is set to true, option behaves as TypeInstanceOID. If Table is set to false, option behaves as TypeInstance.
Note what Table option must be set before setting Instance.
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.
When Table is set to false, this option has no effect.
This value is not applied to counter-values.
This value is not applied to counter-values.
When Table is set to false then this option has no effect.
The FilterOID declares OID to fill table column with values. The FilterValues declares values list to do match. Whether table row will be collected or ignored depends on the FilterIgnoreSelected setting. As with other plugins that use the daemon's ignorelist functionality, a string that starts and ends with a slash is interpreted as a regular expression.
If no selection is configured at all, all table rows are selected.
When Table is set to false then these options has no effect.
See Table and /"IGNORELISTS" for details.
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.
collectd(1), collectd.conf(5), snmpget(1), snmpgetnext(1), variables(5), unix(7)
Florian Forster <octo@collectd.org> Michael Pilat <mike@mikepilat.com>
2021-07-14 | 5.12.0.git |