Ceilometer hardware metric not in meter-list

Issue

• Output from command ceilometer meter-list | grep hardware is empty.

/etc/ceilometer/pipeline.yaml has been extended with:
    - name: meter_snmp
      interval: 600
      resources:
          - snmp://overcloud-compute-0.localdomain
          - snmp://overcloud-compute-1.localdomain
      meters:
          - "hardware.cpu*"
          - "hardware.memory*"
          - "hardware.disk*"
          - "hardware.network*"
          - "hardware.system_stats*"
      sinks:
          - meter_sink

• sample output from grep 'Polling pollster' /var/log/ceilometer/central.log

2017-06-12 22:05:54.652 365986 INFO ceilometer.agent.manager [-] Polling pollster hardware.memory.swap.total in the context of meter_snmp
2017-06-12 22:05:54.717 365986 INFO ceilometer.agent.manager [-] Polling pollster hardware.network.outgoing.errors in the context of meter_snmp
2017-06-12 22:05:55.008 365986 INFO ceilometer.agent.manager [-] Polling pollster hardware.cpu.load.5min in the context of meter_snmp
2017-06-12 22:05:55.148 365986 INFO ceilometer.agent.manager [-] Polling pollster hardware.memory.used in the context of meter_snmp
2017-06-12 22:05:55.226 365986 INFO ceilometer.agent.manager [-] Polling pollster hardware.system_stats.io.outgoing.blocks in the context of meter_snmp