LitmusEdge 4.0.x API Documentation/DeviceHub/DeviceHub Prometheus Metrics - LE, LEM, LUNS API Docs

Prometheus Metrics

GET {{edgeUrl}}/devicehub/metrics

Prometheus Metrics

Returns DeviceHub runtime metrics in the Prometheus exposition format. Suitable for direct Prometheus scraping, ad-hoc curl inspection, or any client that understands the text-based exposition format.

The response is text/plain with no streaming, no compression by default, and no pagination. One scrape returns the complete snapshot of every metric for every device.

Endpoint

GET {{edgeUrl}}/devicehub/metrics

Authentication

HTTP Basic Auth. Username is your API token, password is empty. Tokens are managed under System > Access Control > Tokens.

Parameters

None.

Response

200 OK -- text/plain; version=0.0.4. Standard Prometheus exposition.

Each metric is preceded by # HELP and # TYPE lines, then one line per labelled series. All metrics carry id (device UUID) and name (device name with spaces replaced by _).

Metric reference

Metric	Type	Description
`edge_dh_device_online_status`	gauge	`1` when the device's worker reports a healthy upstream connection, `0` otherwise. Mirrors `Device Connection Status`.
`edge_dh_device_tags`	gauge	Count of registers (tags) currently configured on the device. Same value as `List Registers from Single Device > TotalCount`.
`edge_dh_failed_tags`	counter	Total number of register reads that have failed since the DeviceHub service started. Resets on service restart.
`edge_dh_processed_tags`	counter	Total number of register reads that have succeeded since the DeviceHub service started. Resets on service restart.

Example response (truncated)

# HELP edge_dh_device_online_status
# TYPE edge_dh_device_online_status gauge
edge_dh_device_online_status{id="41FBD12E-C6CD-4539-AD50-336D278B207C",name="Rack_2b_M258"} 1
edge_dh_device_online_status{id="474E42B0-C7B8-42DE-8DE2-FFED7030A563",name="DTA_windows_tia"} 0

# HELP edge_dh_device_tags
# TYPE edge_dh_device_tags gauge
edge_dh_device_tags{id="41FBD12E-C6CD-4539-AD50-336D278B207C",name="Rack_2b_M258"} 1
edge_dh_device_tags{id="779F42F3-54FC-4A87-B9A6-CD39CFA4A97D",name="Simulator2"} 4

# HELP edge_dh_failed_tags
# TYPE edge_dh_failed_tags counter
edge_dh_failed_tags{id="41FBD12E-C6CD-4539-AD50-336D278B207C",name="Rack_2b_M258"} 14
edge_dh_failed_tags{id="4C4B9CCC-F5E4-4C2E-A4C0-EAF5C32B0D1A",name="AB_CLX_API_testing"} 2.080253e+06

# HELP edge_dh_processed_tags
# TYPE edge_dh_processed_tags counter
edge_dh_processed_tags{id="41FBD12E-C6CD-4539-AD50-336D278B207C",name="Rack_2b_M258"} 2.774419e+06
edge_dh_processed_tags{id="89C52E9A-0901-4D8D-B842-7B533F64E1B7",name="ClassificationSimulator"} 2.2195712e+07

Large counters are exposed in scientific notation (2.080253e+06) which Prometheus parses natively.

Useful PromQL recipes

# Devices currently offline
edge_dh_device_online_status == 0

# Per-device read failure rate over 5m
rate(edge_dh_failed_tags[5m])

# Per-device read success rate over 5m
rate(edge_dh_processed_tags[5m])

# Tag-read success ratio
rate(edge_dh_processed_tags[5m])
  / (rate(edge_dh_processed_tags[5m]) + rate(edge_dh_failed_tags[5m]))

# Total tags per device, ranked
topk(10, edge_dh_device_tags)

Scrape configuration

scrape_configs:
  - job_name: 'litmusedge-devicehub'
    scheme: https
    tls_config:
      insecure_skip_verify: true
    metrics_path: /devicehub/metrics
    basic_auth:
      username: '<api-token>'
      password: ''
    static_configs:
      - targets: ['10.17.8.42']

Use a non-insecure_skip_verify config in production: install the device CA in your Prometheus container or mount it via tls_config.ca_file.

Errors

HTTP status	When it happens
`400 Bad Request`	Missing or malformed query/body parameter.
`401 Unauthorized`	Missing or invalid credentials.
`403 Forbidden`	Token lacks permission for this operation.
`404 Not Found`	Target entity does not exist.
`5xx`	Service is unreachable, restarting, or internally errored. Inspect device logs under `System > Support`.

Scrape-specific notes

A 401 on scrape usually means the API token expired or was rotated. Update basic_auth.username and reload Prometheus.
The endpoint does not implement HTTP conditional GETs (If-None-Match, If-Modified-Since); every scrape returns a full snapshot.
For multi-device deployments, scrape each LE host as its own target rather than aggregating client-side -- it preserves the per-device labels for cross-device alerts.

TLS note: edge devices use a self-signed certificate by default. Either install the device CA in your client trust store or disable certificate verification when calling this endpoint directly.

Response

Status: 200 OK

# HELP edge_dh_device_online_status 
# TYPE edge_dh_device_online_status gauge
edge_dh_device_online_status{id="22416E46-4830-4A00-8BFD-45B2CB9978E1",name="apiTestDevice"} 1
edge_dh_device_online_status{id="41FBD12E-C6CD-4539-AD50-336D278B207C",name="Rack_2b_M258"} 1
edge_dh_device_online_status{id="474E42B0-C7B8-42DE-8DE2-FFED7030A563",name="DTA_windows_tia"} 0
edge_dh_device_online_status{id="4C4B9CCC-F5E4-4C2E-A4C0-EAF5C32B0D1A",name="AB_CLX_API_testing"} 0
edge_dh_device_online_status{id="779F42F3-54FC-4A87-B9A6-CD39CFA4A97D",name="Simulator2"} 1
edge_dh_device_online_status{id="89C52E9A-0901-4D8D-B842-7B533F64E1B7",name="ClassificationSimulator"} 1
edge_dh_device_online_status{id="BAFD349E-21B6-408A-AE2F-B9C682912571",name="Boiler"} 0
edge_dh_device_online_status{id="CDC283FB-72E2-42DF-A587-4D6299D70C9A",name="sim1"} 1
# HELP edge_dh_device_tags 
# TYPE edge_dh_device_tags gauge
edge_dh_device_tags{id="22416E46-4830-4A00-8BFD-45B2CB9978E1",name="apiTestDevice"} 0
edge_dh_device_tags{id="41FBD12E-C6CD-4539-AD50-336D278B207C",name="Rack_2b_M258"} 1
edge_dh_device_tags{id="474E42B0-C7B8-42DE-8DE2-FFED7030A563",name="DTA_windows_tia"} 0
edge_dh_device_tags{id="4C4B9CCC-F5E4-4C2E-A4C0-EAF5C32B0D1A",name="AB_CLX_API_testing"} 1
edge_dh_device_tags{id="779F42F3-54FC-4A87-B9A6-CD39CFA4A97D",name="Simulator2"} 4
edge_dh_device_tags{id="89C52E9A-0901-4D8D-B842-7B533F64E1B7",name="ClassificationSimulator"} 8
edge_dh_device_tags{id="BAFD349E-21B6-408A-AE2F-B9C682912571",name="Boiler"} 0
edge_dh_device_tags{id="CDC283FB-72E2-42DF-A587-4D6299D70C9A",name="sim1"} 2
# HELP edge_dh_failed_tags 
# TYPE edge_dh_failed_tags counter
edge_dh_failed_tags{id="22416E46-4830-4A00-8BFD-45B2CB9978E1",name="apiTestDevice"} 0
edge_dh_failed_tags{id="41FBD12E-C6CD-4539-AD50-336D278B207C",name="Rack_2b_M258"} 14
edge_dh_failed_tags{id="474E42B0-C7B8-42DE-8DE2-FFED7030A563",name="DTA_windows_tia"} 0
edge_dh_failed_tags{id="4C4B9CCC-F5E4-4C2E-A4C0-EAF5C32B0D1A",name="AB_CLX_API_testing"} 2.080253e+06
edge_dh_failed_tags{id="779F42F3-54FC-4A87-B9A6-CD39CFA4A97D",name="Simulator2"} 0
edge_dh_failed_tags{id="89C52E9A-0901-4D8D-B842-7B533F64E1B7",name="ClassificationSimulator"} 0
edge_dh_failed_tags{id="BAFD349E-21B6-408A-AE2F-B9C682912571",name="Boiler"} 0
edge_dh_failed_tags{id="CDC283FB-72E2-42DF-A587-4D6299D70C9A",name="sim1"} 0
# HELP edge_dh_processed_tags 
# TYPE edge_dh_processed_tags counter
edge_dh_processed_tags{id="22416E46-4830-4A00-8BFD-45B2CB9978E1",name="apiTestDevice"} 0
edge_dh_processed_tags{id="41FBD12E-C6CD-4539-AD50-336D278B207C",name="Rack_2b_M258"} 2.774419e+06
edge_dh_processed_tags{id="474E42B0-C7B8-42DE-8DE2-FFED7030A563",name="DTA_windows_tia"} 0
edge_dh_processed_tags{id="4C4B9CCC-F5E4-4C2E-A4C0-EAF5C32B0D1A",name="AB_CLX_API_testing"} 0
edge_dh_processed_tags{id="779F42F3-54FC-4A87-B9A6-CD39CFA4A97D",name="Simulator2"} 1.1097856e+07
edge_dh_processed_tags{id="89C52E9A-0901-4D8D-B842-7B533F64E1B7",name="ClassificationSimulator"} 2.2195712e+07
edge_dh_processed_tags{id="BAFD349E-21B6-408A-AE2F-B9C682912571",name="Boiler"} 0
edge_dh_processed_tags{id="CDC283FB-72E2-42DF-A587-4D6299D70C9A",name="sim1"} 5.548928e+06