gnmic monitoring H3C switch, returning JSON data but Prometheus metrics are abnormal

[wm55555]

I am using gnmic to subscribe to telemetry from an H3C switch. The subscription successfully returns JSON data (shown below), but when I scrape the Prometheus exporter endpoint, the metric only shows h3c_Ifmgr_Statistics_Interface{...} 1 instead of exposing the individual fields from the JSON response (like InPkts, InOctets, InRate, etc.).

Configuration (gnmic.yaml):

tingyu@630-10.16.254.114:~/gnmic$ cat gnmic.yaml
targets:
h3c_switch:
address: 10.88.43.21:50051
insecure: true
metadata:
token_id: "00000000116e17359db5141af3ed55c879c1"

subscriptions:
if_stats:
paths:
- "Ifmgr/Statistics/Interface[Name=GigabitEthernet1/0/48]"
mode: stream
stream-mode: sample
sample-interval: 3s
encoding: json_ietf

outputs:
console:
type: file
filename: /dev/stdout
format: event
my_prom_exporter:
type: prometheus
listen: ":9273"
path: "/metrics"
metric-prefix: "h3c"
strings-as-labels: true

Command output

tingyu@630-10.16.254.114:~/gnmic$ gnmic --config gnmic.yaml subscribe --log
time=2026-06-12T11:25:56.707+08:00 level=INFO msg="gnmic version" version=0.46.0 commit=0e753af5 date=2026-05-14T22:18:43Z gitURL=https://github.com/openconfig/gnmic docs=https://gnmic.openconfig.net
time=2026-06-12T11:25:56.707+08:00 level=INFO msg="using config file" path=gnmic.yaml
time=2026-06-12T11:25:56.707+08:00 level=INFO msg="starting output" type=file
time=2026-06-12T11:25:56.708+08:00 level=INFO msg="initialized file output" output=file name=console config="{"Name":"console","FileName":"/dev/stdout","FileType":"","Format":"event","Multiline":false,"Indent":"","Separator":"\n","SplitEvents":false,"OverrideTimestamps":false,"AddTarget":"","TargetTemplate":"","EventProcessors":null,"MsgTemplate":"","ConcurrencyLimit":1000,"EnableMetrics":false,"Debug":false,"CalculateLatency":false,"Rotation":null}"
time=2026-06-12T11:25:56.708+08:00 level=INFO msg="starting output" type=prometheus
time=2026-06-12T11:25:56.709+08:00 level=INFO msg="initialized prometheus output" output=prometheus name=my_prom_exporter config="{"buffer-size":10000,"expiration":60000000000,"listen":":9273","metric-prefix":"h3c","name":"my_prom_exporter","num-workers":1,"path":"/metrics","strings-as-labels":true,"timeout":10000000000}"
time=2026-06-12T11:25:56.709+08:00 level=INFO msg="queuing target" target=h3c_switch
time=2026-06-12T11:25:56.709+08:00 level=INFO msg="subscribing to target" target=h3c_switch
time=2026-06-12T11:25:56.709+08:00 level=INFO msg="starting target listener" target=h3c_switch
time=2026-06-12T11:25:56.709+08:00 level=INFO msg="target gNMI client created" target=h3c_switch
time=2026-06-12T11:25:56.709+08:00 level=INFO msg="sending gNMI SubscribeRequest" target=h3c_switch subscribe="subscribe:{subscription:{path:{elem:{name:"Ifmgr"} elem:{name:"Statistics"} elem:{name:"Interface" key:{key:"Name" value:"GigabitEthernet1/0/48"}}} mode:SAMPLE sample_interval:3000000000} encoding:JSON_IETF}" mode=STREAM encoding=JSON_IETF
[{"name":"if_stats","timestamp":1796527565878966000,"tags":{"Interface_Name":"GigabitEthernet1/0/48","source":"h3c_switch","subscription-name":"if_stats"},"values":{"/Ifmgr/Statistics/Interface":[{"ifmgr-data:AbbreviatedName":"GE1/0/48","ifmgr-data:IfIndex":48,"ifmgr-data:InDiscards":4452,"ifmgr-data:InErrors":0,"ifmgr-data:InNUcastPkts":127963063,"ifmgr-data:InOctets":86628066417,"ifmgr-data:InPktRate":23,"ifmgr-data:InPkts":893957015,"ifmgr-data:InRate":2332,"ifmgr-data:InUcastPkts":765993952,"ifmgr-data:InUnknownProtos":0,"ifmgr-data:LastClear":"0000-00-00T00:00:00","ifmgr-data:Name":"GigabitEthernet1/0/48","ifmgr-data:OutDiscards":0,"ifmgr-data:OutErrors":0,"ifmgr-data:OutNUcastPkts":23136465,"ifmgr-data:OutOctets":1530879888879,"ifmgr-data:OutPktRate":25,"ifmgr-data:OutPkts":1629851559,"ifmgr-data:OutRate":6253,"ifmgr-data:OutUcastPkts":1606715094}]}}]

Prometheus /metrics output:

tingyu@630-10.16.254.114:~/gnmic$ curl http://127.0.0.1:9273/metrics

HELP h3c_Ifmgr_Statistics_Interface gNMIc generated metric

TYPE h3c_Ifmgr_Statistics_Interface untyped

h3c_Ifmgr_Statistics_Interface{Interface="",Interface_Name="GigabitEthernet1/0/48",source="h3c_switch",subscription_name="if_stats"} 1
Why does the Prometheus metric show a value of 1 instead of the actual statistics values from the JSON? How can I configure gnmic to expose each field (e.g., InPkts, InOctets, InRate, etc.) as separate Prometheus metrics?