Migrating to the SNMP Core Check (in Go) from the Python-based Check

Overview

The Datadog Agent 7.27.0 introduces a new SNMP check version in Go that has both memory and performance improvements to the Agent when monitoring devices using SNMP. The purpose of this guide is to assist in migration over to the new core check.

Agent v7.27.0 changes

  • Autodiscovery is now a core Agent process, and needs to be loaded in the main SNMP integration check with loader:core under the init_config, and configured in the main Datadog Agent datadog.yaml.

  • Direct reference to MIBs by their human readable names only are no longer supported. Instead, all OID references should be made by their numerical address, and human readable name. All Datadog shipped profiles have been updated, but custom profiles will need to be updated. Examples for migration are provided below.

  • The Core check does not support manually compiling MIBs to be used as a profile, therefore the following parameters are no longer supported:

    • mibs_folder
    • optimize_mib_memory_usage
    • enforce_mib_constraints
    • bulk_threshold - Removed this in favor of other GET functions

Instructions

  1. Upgrade to Datadog Agent version 7.27+ for your corresponding Agent platform.

  2. Update the init_config in the SNMP check to reference the new core check in snmp.d/conf.yaml.

  init_config:
      loader: core
  1. The following step is only applicable if you use Autodiscovery/subnet scanning: Move the configuration for each instance (subnet) from the SNMP check configuration to the main Datadog Agent datadog.yaml.
listeners:
  - name: snmp
snmp_listener:
  workers: 100  # number of workers used to discover devices concurrently
  discovery_interval: 3600  # interval between each autodiscovery in seconds
  loader: core  # use core check implementation of SNMP integration. recommended
  use_device_id_as_hostname: true  # recommended
  configs:
    - network_address: 10.10.0.0/24  # CIDR subnet
      snmp_version: 2
      port: 161
      community_string: '***'  # enclose with single quote
      tags:
      - "key1:val1"
      - "key2:val2"
    - network_address: 10.20.0.0/24
      snmp_version: 2
      port: 161
      community_string: '***'
      tags:
      - "key1:val1"
      - "key2:val2"
listeners:
  - name: snmp
snmp_listener:
  workers: 100  # number of workers used to discover devices concurrently
  discovery_interval: 3600  # interval between each autodiscovery in seconds
  loader: core  # use core check implementation of SNMP integration. recommended
  use_device_id_as_hostname: true  # recommended
  configs:
    - network_address: 10.10.0.0/24  # CIDR subnet
      snmp_version: 3
      user: 'user'
      authProtocol: 'SHA256'  # choices: MD5, SHA, SHA224, SHA256, SHA384, SHA512
      authKey: 'fakeKey'  # enclose with single quote
      privProtocol: 'AES256'  # choices: DES, AES (128 bits), AES192, AES192C, AES256, AES256C
      privKey: 'fakePrivKey'  # enclose with single quote
      tags:
        - 'key1:val1'
        - 'key2:val2'
    - network_address: 10.20.0.0/24
      snmp_version: 3
      user: 'user'
      authProtocol: 'SHA256'
      authKey: 'fakeKey'
      privProtocol: 'AES256'
      privKey: 'fakePrivKey'
      tags:
        - 'key1:val1'
        - 'key2:val2'

Migrating custom profiles (independent of deployment)

SNMP no longer supports only listing OIDs by their human-readable name. You can reference by address (table name and index) or MIB entry address. If you have written any profiles yourself or modified any existing profiles, migrate them to the new format. Below are examples of migration.

Scalar symbols

Before Agent 7.27.0:

scalar_symbols.yaml

metrics:
  - MIB: HOST-RESOURCES-MIB
    symbol: hrSystemUptime

With Agent 7.27.0:

scalar_symbols_7_27.yaml

metrics:
  - MIB: HOST-RESOURCES-MIB
    symbol:
      OID: 1.3.6.1.2.1.25.1.1.0
      name: hrSystemUptime

Table symbols

Before Agent 7.27.0:

table_symbols.yaml

metrics:
  - MIB: HOST-RESOURCES-MIB
    table: hrStorageTable
    symbols:
      - hrStorageAllocationUnits
      - hrStoageSize
    metrics_tags:
      - tag: storagedec
        column: hrStorageDescr

With Agent 7.27.0:

table_symbols_7_27.yaml

metrics:
  - MIB: HOST-RESOURCES-MIB
    table:
      OID: 1.3.6.1.2.1.25.2.3
      name: hrStorageTable
    symbols:
      - OID: 1.3.6.1.2.1.25.2.3.1.4
        name: hrStorageAllocationUnits
      - OID: 1.3.6.1.2.1.25.2.3.1.5
        name: hrStoageSize
    metrics_tags:
      - tag: storagedec
        column:
          OID: 1.3.6.1.2.1.25.2.3.1.3
          name: hrStorageDescr

Metrics tags

Before Agent 7.27.0:

metrics_tags.yaml

metrics_tags:
  - symbol: sysName
    tag: snmp_host

With Agent 7.27.0:

metrics_tags_7_27.yaml

metrics_tags:
  - OID: 1.3.6.1.2.1.1.5.0
    symbol: sysName
    tag: snmp_host