open-nomad/website/source/docs/agent/telemetry.html.md

---
layout: "docs"
page_title: "Telemetry"
sidebar_current: "docs-agent-telemetry"
description: |-
  Learn about the telemetry data available in Nomad.
---

# Telemetry

The Nomad agent collects various runtime metrics about the performance of
different libraries and subsystems. These metrics are aggregated on a ten
second interval and are retained for one minute.

To view this data, you must send a signal to the Nomad process: on Unix,
this is `USR1` while on Windows it is `BREAK`. Once Nomad receives the signal,
it will dump the current telemetry information to the agent's `stderr`.

This telemetry information can be used for debugging or otherwise
getting a better view of what Nomad is doing.

Telemetry information can be streamed to both [statsite](https://github.com/armon/statsite)
as well as statsd based on providing the appropriate configuration options.

To configure the telemetry output please see the [agent
configuration](/docs/agent/configuration/telemetry.html).

Below is sample output of a telemetry dump:

```text
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.nomad.broker.total_blocked': 0.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.nomad.plan.queue_depth': 0.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.runtime.malloc_count': 7568.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.runtime.total_gc_runs': 8.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.nomad.broker.total_ready': 0.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.runtime.num_goroutines': 56.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.runtime.sys_bytes': 3999992.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.runtime.heap_objects': 4135.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.nomad.heartbeat.active': 1.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.nomad.broker.total_unacked': 0.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.nomad.broker.total_waiting': 0.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.runtime.alloc_bytes': 634056.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.runtime.free_count': 3433.000
[2015-09-17 16:59:40 -0700 PDT][G] 'nomad.runtime.total_gc_pause_ns': 6572135.000
[2015-09-17 16:59:40 -0700 PDT][C] 'nomad.memberlist.msg.alive': Count: 1 Sum: 1.000
[2015-09-17 16:59:40 -0700 PDT][C] 'nomad.serf.member.join': Count: 1 Sum: 1.000
[2015-09-17 16:59:40 -0700 PDT][C] 'nomad.raft.barrier': Count: 1 Sum: 1.000
[2015-09-17 16:59:40 -0700 PDT][C] 'nomad.raft.apply': Count: 1 Sum: 1.000
[2015-09-17 16:59:40 -0700 PDT][C] 'nomad.nomad.rpc.query': Count: 2 Sum: 2.000
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.serf.queue.Query': Count: 6 Sum: 0.000
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.nomad.fsm.register_node': Count: 1 Sum: 1.296
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.serf.queue.Intent': Count: 6 Sum: 0.000
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.runtime.gc_pause_ns': Count: 8 Min: 126492.000 Mean: 821516.875 Max: 3126670.000 Stddev: 1139250.294 Sum: 6572135.000
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.raft.leader.dispatchLog': Count: 3 Min: 0.007 Mean: 0.018 Max: 0.039 Stddev: 0.018 Sum: 0.054
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.nomad.leader.reconcileMember': Count: 1 Sum: 0.007
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.nomad.leader.reconcile': Count: 1 Sum: 0.025
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.raft.fsm.apply': Count: 1 Sum: 1.306
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.nomad.client.get_allocs': Count: 1 Sum: 0.110
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.nomad.worker.dequeue_eval': Count: 29 Min: 0.003 Mean: 363.426 Max: 503.377 Stddev: 228.126 Sum: 10539.354
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.serf.queue.Event': Count: 6 Sum: 0.000
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.raft.commitTime': Count: 3 Min: 0.013 Mean: 0.037 Max: 0.079 Stddev: 0.037 Sum: 0.110
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.nomad.leader.barrier': Count: 1 Sum: 0.071
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.nomad.client.register': Count: 1 Sum: 1.626
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.nomad.eval.dequeue': Count: 21 Min: 500.610 Mean: 501.753 Max: 503.361 Stddev: 1.030 Sum: 10536.813
[2015-09-17 16:59:40 -0700 PDT][S] 'nomad.memberlist.gossip': Count: 12 Min: 0.009 Mean: 0.017 Max: 0.025 Stddev: 0.005 Sum: 0.204
```

# Key Metrics

When telemetry is being streamed to statsite or statsd, `interval` is defined to
be their flush interval. Otherwise, the interval can be assumed to be 10 seconds
when retrieving metrics using the above described signals.

<table class="table table-bordered table-striped">
  <tr>
    <th>Metric</th>
    <th>Description</th>
    <th>Unit</th>
    <th>Type</th>
  </tr>
  <tr>
    <td>`nomad.runtime.num_goroutines`</td>
    <td>Number of goroutines and general load pressure indicator</td>
    <td># of goroutines</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.runtime.alloc_bytes`</td>
    <td>Memory utilization</td>
    <td># of bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.runtime.heap_objects`</td>
    <td>Number of objects on the heap. General memory pressure indicator</td>
    <td># of heap objects</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.raft.apply`</td>
    <td>Number of Raft transactions</td>
    <td>Raft transactions / `interval`</td>
    <td>Counter</td>
  </tr>
  <tr>
    <td>`nomad.raft.replication.appendEntries`</td>
    <td>Raft transaction commit time</td>
    <td>ms / Raft Log Append</td>
    <td>Timer</td>
  </tr>
  <tr>
    <td>`nomad.raft.leader.lastContact`</td>
    <td>Time since last contact to leader. General indicator of Raft latency</td>
    <td>ms / Leader Contact</td>
    <td>Timer</td>
  </tr>
  <tr>
    <td>`nomad.broker.total_ready`</td>
    <td>Number of evaluations ready to be processed</td>
    <td># of evaluations</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.broker.total_unacked`</td>
    <td>Evaluations dispatched for processing but incomplete</td>
    <td># of evaluations</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.broker.total_blocked`</td>
    <td>
        Evaluations that are blocked til an existing evaluation for the same job
        completes
    </td>
    <td># of evaluations</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.plan.queue_depth`</td>
    <td>Number of scheduler Plans waiting to be evaluated</td>
    <td># of plans</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.plan.submit`</td>
    <td>
        Time to submit a scheduler Plan. Higher values cause lower scheduling
        throughput
    </td>
    <td>ms / Plan Submit</td>
    <td>Timer</td>
  </tr>
  <tr>
    <td>`nomad.plan.evaluate`</td>
    <td>
        Time to validate a scheduler Plan. Higher values cause lower scheduling
        throughput. Similar to `nomad.plan.submit` but does not include RPC time
        or time in the Plan Queue
    </td>
    <td>ms / Plan Evaluation</td>
    <td>Timer</td>
  </tr>
  <tr>
    <td>`nomad.worker.invoke_scheduler.<type>`</td>
    <td>Time to run the scheduler of the given type</td>
    <td>ms / Scheduler Run</td>
    <td>Timer</td>
  </tr>
  <tr>
    <td>`nomad.worker.wait_for_index`</td>
    <td>
        Time waiting for Raft log replication from leader. High delays result in
        lower scheduling throughput
    </td>
    <td>ms / Raft Index Wait</td>
    <td>Timer</td>
  </tr>
  <tr>
    <td>`nomad.heartbeat.active`</td>
    <td>
        Number of active heartbeat timers. Each timer represents a Nomad Client
        connection
    </td>
    <td># of heartbeat timers</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.heartbeat.invalidate`</td>
    <td>
        The length of time it takes to invalidate a Nomad Client due to failed
        heartbeats
    </td>
    <td>ms / Heartbeat Invalidation</td>
    <td>Timer</td>
  </tr>
  <tr>
    <td>`nomad.rpc.query`</td>
    <td>Number of RPC queries</td>
    <td>RPC Queries / `interval`</td>
    <td>Counter</td>
  </tr>
  <tr>
    <td>`nomad.rpc.request`</td>
    <td>Number of RPC requests being handled</td>
    <td>RPC Requests / `interval`</td>
    <td>Counter</td>
  </tr>
  <tr>
    <td>`nomad.rpc.request_error`</td>
    <td>Number of RPC requests being handled that result in an error</td>
    <td>RPC Errors / `interval`</td>
    <td>Counter</td>
  </tr>
</table>

# Client Metrics

The Nomad client emits metrics related to the resource usage of the allocations
and tasks running on it and the node itself.  Operators have to explicity turn
on publishing host and allocation metrics. Publishing allocation and host
metrics can be turned on by setting the value of `publish_allocation_metrics`
`publish_node_metrics` to `true`.


By default the collection interval is 1 second but it can be changed by the
changing the value of the `collection_interval` key in the `telemetry`
configuration block.

Please see the [agent configuration](/docs/agent/configuration/telemetry.html)
page for more details.

## Host Metrics

<table class="table table-bordered table-striped">
  <tr>
    <th>Metric</th>
    <th>Description</th>
    <th>Unit</th>
    <th>Type</th>
  </tr>
  <tr>
    <td>`nomad.client.host.memmory.<HostID>.total`</td>
    <td>Total amount of physical memory on the node</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.memmory.<HostID>.available`</td>
    <td>Total amount of memory available to processes which includes free and
    cached memory</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.memory.<HostID>.used`</td>
    <td>Amount of memory used by processes</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.memory.<HostID>.free`</td>
    <td>Amount of memory which is free</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.uptime.<HostID>`</td>
    <td>Uptime of the host running the Nomad client</td>
    <td>Seconds</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.cpu.<HostID>.<CPU-Core>.total`</td>
    <td>Total CPU utilization</td>
    <td>Percentage</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.cpu.<HostID>.<CPU-Core>.user`</td>
    <td>CPU utilization in the user space</td>
    <td>Percentage</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.cpu.<HostID>.<CPU-Core>.system`</td>
    <td>CPU utilization in the system space</td>
    <td>Percentage</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.cpu.<HostID>.<CPU-Core>.idle`</td>
    <td>Idle time spent by the CPU</td>
    <td>Percentage</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.disk.<HostID>.<Device-Name>.size`</td>
    <td>Total size of the device</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.disk.<HostID>.<Device-Name>.used`</td>
    <td>Amount of space which has been used</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.disk.<HostID>.<Device-Name>.available`</td>
    <td>Amount of space which is available</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.disk.<HostID>.<Device-Name>.used_percent`</td>
    <td>Percentage of disk space used</td>
    <td>Percentage</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.host.disk.<HostID>.<Device-Name>.inodes_percent`</td>
    <td>Disk space consumed by the inodes</td>
    <td>Percent</td>
    <td>Gauge</td>
  </tr>
</table>

## Allocation Metrics

<table class="table table-bordered table-striped">
  <tr>
    <th>Metric</th>
    <th>Description</th>
    <th>Unit</th>
    <th>Type</th>
  </tr>
  <tr>
    <td>`nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.rss`</td>
    <td>Amount of RSS memory consumed by the task</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.cache`</td>
    <td>Amount of memory cached by the task</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.swap`</td>
    <td>Amount of memory swapped by the task</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.max_usage`</td>
    <td>Maximum amount of memory ever used by the task</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.kernel_usage`</td>
    <td>Amount of memory used by the kernel for this task</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.kernel_max_usage`</td>
    <td>Maximum amount of memory ever used by the kernel for this task</td>
    <td>Bytes</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.cpu.total_percent`</td>
    <td>Total CPU resources consumed by the task across all cores</td>
    <td>Percentage</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.cpu.system`</td>
    <td>Total CPU resources consumed by the task in the system space</td>
    <td>Percentage</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.allocs.<Job>.TaskGroup>.<AllocID>.<Task>.cpu.user`</td>
    <td>Total CPU resources consumed by the task in the user space</td>
    <td>Percentage</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.cpu.throttled_time`</td>
    <td>Total time that the task was throttled</td>
    <td>Nanoseconds</td>
    <td>Gauge</td>
  </tr>
  <tr>
    <td>`nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.cpu.total_ticks`</td>
    <td>CPU ticks consumed by the process in the last collection interval</td>
    <td>Integer</td>
    <td>Gauge</td>
  </tr>
</table>

# Metric Types

<table class="table table-bordered table-striped">
  <tr>
    <th>Type</th>
    <th>Description</th>
    <th>Quantiles</th>
  </tr>
  <tr>
    <td>Gauge</td>
    <td>
        Gauge types report an absolute number at the end of the aggregation
        interval
    </td>
    <td>false</td>
  </tr>
  <tr>
    <td>Counter</td>
    <td>
        Counts are incremented and flushed at the end of the aggregation
        interval and then are reset to zero
    </td>
    <td>true</td>
  </tr>
  <tr>
    <td>Timer</td>
    <td>
        Timers measure the time to complete a task and will include quantiles,
        means, standard deviation, etc per interval.
    </td>
    <td>true</td>
  </tr>
</table>