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An example of a polling scenario

In the following example, there are 4 hosts you want to poll from:

  1. 10.202.4.201:161
  2. 10.202.4.202:161
  3. 10.202.4.203:161
  4. 10.202.4.204:163

To retrieve data from the device efficiently, first determine the specific data needed. Instead of walking through the entire 1.3.6.1, limit the walk to poll only the necessary data. Configure the IF-MIB family for interfaces and the UCD-SNMP-MIB for CPU-related statistics. In the scheduler section of values.yaml, define the target group and establish the polling parameters, known as the profile, to gather the desired data precisely. See the following example:

scheduler:
  logLevel: "INFO"
  profiles: |
    small_walk:
      condition:
        type: "walk"
      varBinds:
        - ["IF-MIB"]
        - ["UCD-SNMP-MIB"]
    switch_profile:
      frequency: 60
      varBinds:
        - ["IF-MIB", "ifDescr"]
        - ["IF-MIB", "ifAdminStatus"]
        - ["IF-MIB", "ifOperStatus"]
        - ["IF-MIB", "ifName"]
        - ["IF-MIB", "ifAlias"]
        - ["IF-MIB", "ifIndex"]
        - ["IF-MIB", "ifInDiscards"]
        - ["IF-MIB", "ifInErrors"]
        - ["IF-MIB", "ifInOctets"]
        - ["IF-MIB", "ifOutDiscards"]
        - ["IF-MIB", "ifOutErrors"]
        - ["IF-MIB", "ifOutOctets"]
        - ["IF-MIB", "ifOutQLen"]
        - ["UCD-SNMP-MIB"]
  groups: |
    switch_group:
      - address: 10.202.4.201
      - address: 10.202.4.202
      - address: 10.202.4.203
      - address: 10.202.4.204
        port: 163

It is required to pass the proper instruction of what to do for the SC4SNMP instance. To do this, append a new row to poller.inventory:

poller:
  logLevel: "WARN"
  inventory: |
    address,port,version,community,secret,security_engine,walk_interval,profiles,smart_profiles,delete
    switch_group,,2c,public,,,2000,small_walk;switch_profile,,

The provided example configuration will make:

  1. Walk devices from switch_group with IF-MIB and UCD-SNMP-MIB every 2000 seconds
  2. Poll specific IF-MIB fields and the whole UCD-SNMP-MIB every 60 seconds

Note: You can also limit the walk profile even more if you want to enhance the performance.

It makes sense to put the textual values in the walk that aren’t required to be constantly monitored, and monitor only the metrics you’re interested in:

small_walk:
  condition:
    type: "walk"
  varBinds:
    - ["IF-MIB", "ifDescr"]
    - ["IF-MIB", "ifAdminStatus"]
    - ["IF-MIB", "ifOperStatus"]
    - ["IF-MIB", "ifName"]
    - ["IF-MIB", "ifAlias"]
    - ["IF-MIB", "ifIndex"]
switch_profile:
  frequency: 60
  varBinds:
    - ["IF-MIB", "ifInDiscards"]
    - ["IF-MIB", "ifInErrors"]
    - ["IF-MIB", "ifInOctets"]
    - ["IF-MIB", "ifOutDiscards"]
    - ["IF-MIB", "ifOutErrors"]
    - ["IF-MIB", "ifOutOctets"]
    - ["IF-MIB", "ifOutQLen"]

Afterwards, every metric object will be enriched with the textual values gathered from a walk process. See here for more information about SNMP format.

Now you’re ready to reload SC4SNMP. Run the following helm3 upgrade command:

microk8s helm3 upgrade --install snmp -f values.yaml splunk-connect-for-snmp/splunk-connect-for-snmp --namespace=sc4snmp --create-namespace

See the new pod with the following Running -> Completed state command:

microk8s kubectl get pods -n sc4snmp -w

See the following example output:

NAME                                                          READY   STATUS    RESTARTS   AGE
snmp-splunk-connect-for-snmp-worker-sender-5bc5cf864b-cwmfw   1/1     Running   0          5h52m
snmp-splunk-connect-for-snmp-worker-poller-76dcfb5896-d55pd   1/1     Running   0          5h52m
snmp-splunk-connect-for-snmp-worker-trap-68fb6476db-zl9rb     1/1     Running   0          5h52m
snmp-mibserver-58b558f5b4-zqf85                               1/1     Running   0          5h52m
snmp-splunk-connect-for-snmp-scheduler-57c5878444-k4qv4       1/1     Running   0          5h52m
snmp-splunk-connect-for-snmp-worker-poller-76dcfb5896-bzgrm   1/1     Running   0          5h52m
snmp-splunk-connect-for-snmp-trap-6cb76fcb49-l62f9            1/1     Running   0          5h52m
snmp-splunk-connect-for-snmp-trap-6cb76fcb49-d7c88            1/1     Running   0          5h52m
snmp-mongodb-869cc8586f-kw67q                                 2/2     Running   0          5h52m
snmp-redis-master-0                                           1/1     Running   0          5h52m
snmp-splunk-connect-for-snmp-inventory-g4bs7                  1/1     Running   0          3s
snmp-splunk-connect-for-snmp-inventory-g4bs7                  0/1     Completed   0          5s
snmp-splunk-connect-for-snmp-inventory-g4bs7                  0/1     Completed   0          6s
snmp-splunk-connect-for-snmp-inventory-g4bs7                  0/1     Completed   0          7s

Check the pod’s logs to make sure everything was reloaded correctly, using the following command:

microk8s kubectl logs -f snmp-splunk-connect-for-snmp-inventory-g4bs7  -n sc4snmp

See the following example output:

Successfully connected to redis://snmp-redis-headless:6379/0
Successfully connected to redis://snmp-redis-headless:6379/1
Successfully connected to mongodb://snmp-mongodb:27017
Successfully connected to http://snmp-mibserver/index.csv
{"message": "Loading inventory from /app/inventory/inventory.csv", "time": "2022-09-05T14:30:30.605420", "level": "INFO"}
{"message": "New Record address='10.202.4.201' port=161 version='2c' community='public' secret=None security_engine=None walk_interval=2000 profiles=['switch_profile'] smart_profiles=True delete=False", "time": "2022-09-05T14:30:30.607641", "level": "INFO"}
{"message": "New Record address='10.202.4.202' port=161 version='2c' community='public' secret=None security_engine=None walk_interval=2000 profiles=['switch_profile'] smart_profiles=True delete=False", "time": "2022-09-05T14:30:30.607641", "level": "INFO"}
{"message": "New Record address='10.202.4.203' port=161 version='2c' community='public' secret=None security_engine=None walk_interval=2000 profiles=['switch_profile'] smart_profiles=True delete=False", "time": "2022-09-05T14:30:30.607641", "level": "INFO"}
{"message": "New Record address='10.202.4.204' port=163 version='2c' community='public' secret=None security_engine=None walk_interval=2000 profiles=['switch_profile'] smart_profiles=True delete=False", "time": "2022-09-05T14:30:30.607641", "level": "INFO"}

In some time (depending on how long the walk takes), we’ll see events using the following query:

| mpreview index=netmetrics | search profiles=switch_profile

When groups are used, we can also use querying by the group name, for example:

| mpreview index=netmetrics | search group=switch_group

Querying by profiles/group in Splunk is only possible in the metrics index. Every piece of data being sent by SC4SNMP is formed based on the MIB file’s definition of the SNMP object’s index. The object is forwarded to an event index only if it doesn’t have any metric value inside.

The following is a Splunk raw metrics example:

{
   "frequency":"60",
   "group":"switch_group",
   "ifAdminStatus":"up",
   "ifAlias":"1",
   "ifDescr":"lo",
   "ifIndex":"1",
   "ifName":"lo",
   "ifOperStatus":"up",
   "ifPhysAddress":"1",
   "ifType":"softwareLoopback",
   "profiles":"switch_profile",
   "metric_name:sc4snmp.IF-MIB.ifInDiscards":21877,
   "metric_name:sc4snmp.IF-MIB.ifInErrors":21840,
   "metric_name:sc4snmp.IF-MIB.ifInNUcastPkts":14152789,
   "metric_name:sc4snmp.IF-MIB.ifInOctets":1977814270,
   "metric_name:sc4snmp.IF-MIB.ifInUcastPkts":220098191,
   "metric_name:sc4snmp.IF-MIB.ifInUnknownProtos":1488029,
   "metric_name:sc4snmp.IF-MIB.ifLastChange":124000001,
   "metric_name:sc4snmp.IF-MIB.ifMtu":16436,
   "metric_name:sc4snmp.IF-MIB.ifOutDiscards":21862,
   "metric_name:sc4snmp.IF-MIB.ifOutErrors":21836,
   "metric_name:sc4snmp.IF-MIB.ifOutNUcastPkts":14774727,
   "metric_name:sc4snmp.IF-MIB.ifOutOctets":1346799625,
   "metric_name:sc4snmp.IF-MIB.ifOutQLen":4294967295,
   "metric_name:sc4snmp.IF-MIB.ifOutUcastPkts":74003841,
   "metric_name:sc4snmp.IF-MIB.ifSpeed":10000000
}

or

{
   "frequency":"60",
   "group":"switch_group",
   "laNames":"Load-1",
   "profiles":"switch_profile",
   "metric_name:sc4snmp.UCD-SNMP-MIB.laIndex":1
}