Nomad Autoscaler HTTP API

The Nomad Autoscaler exposes a small, simple API to be used for health checking the agent and obtaining metric data.

Agent Runtime Profiles

This endpoint can be used to retrieve runtime profile information for the Nomad Autoscaler. They are only available when enable_debug is set to true. Refer to Go's documentation for a list of available profiles.

Method	Path	Produces
`GET`	`/debug/pprof`	`text/html`
`GET`	`/debug/pprof/cmdline`	`text/plain`
`GET`	`/debug/pprof/symbol`	`text/plain`
`GET`	`/debug/pprof/profile`	`application/octet-stream`
`GET`	`/debug/pprof/trace`	`application/octet-stream`
`GET`	`/debug/pprof/<pprof profile>`	`application/octet-stream`

Parameters

seconds (int: 3) - Specifies the amount of time to run a profile or trace request for.
debug (int: 0) - Specifies if a given pprof profile should be returned as human readable plain text instead of the pprof binary format. Defaults to 0, setting to 1 enables human readable plain text.

Sample Request

$ curl -O "http://localhost:8080/debug/pprof/goroutine"
$ go tool pprof goroutine

$ curl -O "http://localhost:8080/debug/pprof/profile?seconds=3"
$ go tool pprof profile

$ curl -O "http://localhost:8080/debug/pprof/trace?&seconds=5"
$ go tool trace trace

Health API

This endpoint can be used to query the Nomad Autoscaler agent aliveness. If the agent is alive, the request will return a 200 OK, otherwise it will return a 503 ServiceUnavailable.

Method	Path	Produces
`GET`	`/v1/health`	`application/json`

Sample Request

$ curl https://localhost:8080/v1/health

Metrics API

The /metrics endpoint returns metrics for the current Nomad Autoscaler process.

Method	Path	Produces
`GET`	`/v1/metrics`	`application/json`

Parameters

format (string: "") - Specifies the metrics format to be other than the JSON default. Currently, only prometheus is supported as an alternative format. This is specified as a query string parameter.

Sample Request

$ curl https://localhost:8080/v1/metrics

$ curl https://localhost:8080/v1/metrics?format=prometheus

Sample Response

{
  "Counters": [
    {
      "Count": 1,
      "Labels": {
        "policy_source": "nomad"
      },
      "Max": 1,
      "Mean": 1,
      "Min": 1,
      "Name": "nomad-autoscaler.policy.source.error_count",
      "Rate": 0.1,
      "Stddev": 0,
      "Sum": 1
    }
  ],
  "Gauges": [
    {
      "Labels": {},
      "Name": "nomad-autoscaler.pathfinder.policy.total_num",
      "Value": 0
    },
    {
      "Labels": {},
      "Name": "nomad-autoscaler.pathfinder.runtime.alloc_bytes",
      "Value": 7230328
    },
    {
      "Labels": {},
      "Name": "nomad-autoscaler.pathfinder.runtime.free_count",
      "Value": 137217
    },
    {
      "Labels": {},
      "Name": "nomad-autoscaler.pathfinder.runtime.heap_objects",
      "Value": 90821
    },
    {
      "Labels": {},
      "Name": "nomad-autoscaler.pathfinder.runtime.malloc_count",
      "Value": 228038
    },
    {
      "Labels": {},
      "Name": "nomad-autoscaler.pathfinder.runtime.num_goroutines",
      "Value": 15
    },
    {
      "Labels": {},
      "Name": "nomad-autoscaler.pathfinder.runtime.sys_bytes",
      "Value": 75317504
    },
    {
      "Labels": {},
      "Name": "nomad-autoscaler.pathfinder.runtime.total_gc_pause_ns",
      "Value": 293262
    },
    {
      "Labels": {},
      "Name": "nomad-autoscaler.pathfinder.runtime.total_gc_runs",
      "Value": 4
    }
  ],
  "Points": [],
  "Samples": [],
  "Timestamp": "2020-08-25 10:25:20 +0000 UTC"
}