topology_description:
  type: ReplicaSetNoPrimary
  servers:
  - address: b:27017
    avg_rtt_ms: 5
    type: RSSecondary
    tags:
      data_center: nyc
  - address: c:27017
    avg_rtt_ms: 100
    type: RSSecondary
    tags:
      data_center: nyc
operation: read
read_preference:
  mode: Primary
suitable_servers: []
in_latency_window: []