Nomad
Metrics
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.
This data can be accessed via an HTTP endpoint or via sending a signal to the Nomad process.
As of Nomad version 0.7, this data is available via HTTP at /metrics. See
Metrics for more information.
To view this data via sending 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 as well as statsd based on providing the appropriate configuration options.
To configure the telemetry output please see the agent configuration.
Below is sample output of a telemetry dump:
[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.
| Metric | Description | Unit | Type |
|---|---|---|---|
nomad.runtime.num_goroutines | Number of goroutines and general load pressure indicator | # of goroutines | Gauge |
nomad.runtime.alloc_bytes | Memory utilization | # of bytes | Gauge |
nomad.runtime.heap_objects | Number of objects on the heap. General memory pressure indicator | # of heap objects | Gauge |
nomad.raft.apply | Number of Raft transactions | Raft transactions / `interval` | Counter |
nomad.raft.replication.appendEntries | Raft transaction commit time | ms / Raft Log Append | Timer |
nomad.raft.leader.lastContact | Time since last contact to leader. General indicator of Raft latency | ms / Leader Contact | Timer |
nomad.broker.total_ready | Number of evaluations ready to be processed | # of evaluations | Gauge |
nomad.broker.total_unacked | Evaluations dispatched for processing but incomplete | # of evaluations | Gauge |
nomad.broker.total_blocked | Evaluations that are blocked until an existing evaluation for the same job completes | # of evaluations | Gauge |
nomad.plan.queue_depth | Number of scheduler Plans waiting to be evaluated | # of plans | Gauge |
nomad.plan.submit | Time to submit a scheduler Plan. Higher values cause lower scheduling throughput | ms / Plan Submit | Timer |
nomad.plan.evaluate | 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 | ms / Plan Evaluation | Timer |
nomad.worker.invoke_scheduler.<type> | Time to run the scheduler of the given type | ms / Scheduler Run | Timer |
nomad.worker.wait_for_index | Time waiting for Raft log replication from leader. High delays result in lower scheduling throughput | ms / Raft Index Wait | Timer |
nomad.heartbeat.active | Number of active heartbeat timers. Each timer represents a Nomad Client connection | # of heartbeat timers | Gauge |
nomad.heartbeat.invalidate | The length of time it takes to invalidate a Nomad Client due to failed heartbeats | ms / Heartbeat Invalidation | Timer |
nomad.rpc.query | Number of RPC queries | RPC Queries / `interval` | Counter |
nomad.rpc.request | Number of RPC requests being handled | RPC Requests / `interval` | Counter |
nomad.rpc.request_error | Number of RPC requests being handled that result in an error | RPC Errors / `interval` | Counter |
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 explicitly 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 page for more details.
As of Nomad 0.9, Nomad will emit additional labels for parameterized and
periodic jobs. Nomad
emits the parent job id as a new label parent_id. Also, the labels dispatch_id
and periodic_id are emitted, containing the ID of the specific invocation of the
parameterized or periodic job respectively. For example, a dispatch job with the id
myjob/dispatch-1312323423423, will have the following labels.
| Label | Value |
|---|---|
| job | myjob/dispatch-1312323423423 |
| parent_id | myjob |
| dispatch_id | 1312323423423 |
Host Metrics (post Nomad version 0.7)
Starting in version 0.7, Nomad will emit tagged metrics, in the below format:
| Metric | Description | Unit | Type | Labels |
|---|---|---|---|---|
nomad.client.allocated.cpu | Total amount of CPU shares the scheduler has allocated to tasks | MHz | Gauge | node_id, datacenter |
nomad.client.unallocated.cpu | Total amount of CPU shares free for the scheduler to allocate to tasks | MHz | Gauge | node_id, datacenter |
nomad.client.allocated.memory | Total amount of memory the scheduler has allocated to tasks | Megabytes | Gauge | node_id, datacenter |
nomad.client.unallocated.memory | Total amount of memory free for the scheduler to allocate to tasks | Megabytes | Gauge | node_id, datacenter |
nomad.client.allocated.disk | Total amount of disk space the scheduler has allocated to tasks | Megabytes | Gauge | node_id, datacenter |
nomad.client.unallocated.disk | Total amount of disk space free for the scheduler to allocate to tasks | Megabytes | Gauge | node_id, datacenter |
nomad.client.allocated.network | Total amount of bandwidth the scheduler has allocated to tasks on the given device | Megabits | Gauge | node_id, datacenter, device |
nomad.client.unallocated.network | Total amount of bandwidth free for the scheduler to allocate to tasks on the given device | Megabits | Gauge | node_id, datacenter, device |
nomad.client.host.memory.total | Total amount of physical memory on the node | Bytes | Gauge | node_id, datacenter |
nomad.client.host.memory.available | Total amount of memory available to processes which includes free and cached memory | Bytes | Gauge | node_id, datacenter |
nomad.client.host.memory.used | Amount of memory used by processes | Bytes | Gauge | node_id, datacenter |
nomad.client.host.memory.free | Amount of memory which is free | Bytes | Gauge | node_id, datacenter |
nomad.client.uptime | Uptime of the host running the Nomad client | Seconds | Gauge | node_id, datacenter |
nomad.client.host.cpu.total | Total CPU utilization | Percentage | Gauge | node_id, datacenter, cpu |
nomad.client.host.cpu.user | CPU utilization in the user space | Percentage | Gauge | node_id, datacenter, cpu |
nomad.client.host.cpu.system | CPU utilization in the system space | Percentage | Gauge | node_id, datacenter, cpu |
nomad.client.host.cpu.idle | Idle time spent by the CPU | Percentage | Gauge | node_id, datacenter, cpu |
nomad.client.host.disk.size | Total size of the device | Bytes | Gauge | node_id, datacenter, disk |
nomad.client.host.disk.used | Amount of space which has been used | Bytes | Gauge | node_id, datacenter, disk |
nomad.client.host.disk.available | Amount of space which is available | Bytes | Gauge | node_id, datacenter, disk |
nomad.client.host.disk.used_percent | Percentage of disk space used | Percentage | Gauge | node_id, datacenter, disk |
nomad.client.host.disk.inodes_percent | Disk space consumed by the inodes | Percent | Gauge | node_id, datacenter, disk |
nomad.client.allocs.start | Number of allocations starting | Integer | Counter | node_id, job, task_group |
nomad.client.allocs.running | Number of allocations starting to run | Integer | Counter | node_id, job, task_group |
nomad.client.allocs.failed | Number of allocations failing | Integer | Counter | node_id, job, task_group |
nomad.client.allocs.restart | Number of allocations restarting | Integer | Counter | node_id, job, task_group |
nomad.client.allocs.complete | Number of allocations completing | Integer | Counter | node_id, job, task_group |
nomad.client.allocs.destroy | Number of allocations being destroyed | Integer | Counter | node_id, job, task_group |
Nomad 0.9 adds an additional node_class label from the client's
NodeClass attribute. This label is set to the string "none" if empty.
Host Metrics (deprecated post Nomad 0.7)
The below are metrics emitted by Nomad in versions prior to 0.7. These metrics can be emitted in the below format post-0.7 (as well as the new format, detailed above) but any new metrics will only be available in the new format.
| Metric | Description | Unit | Type |
|---|---|---|---|
nomad.client.allocated.cpu.<HostID> | Total amount of CPU shares the scheduler has allocated to tasks | MHz | Gauge |
nomad.client.unallocated.cpu.<HostID> | Total amount of CPU shares free for the scheduler to allocate to tasks | MHz | Gauge |
nomad.client.allocated.memory.<HostID> | Total amount of memory the scheduler has allocated to tasks | Megabytes | Gauge |
nomad.client.unallocated.memory.<HostID> | Total amount of memory free for the scheduler to allocate to tasks | Megabytes | Gauge |
nomad.client.allocated.disk.<HostID> | Total amount of disk space the scheduler has allocated to tasks | Megabytes | Gauge |
nomad.client.unallocated.disk.<HostID> | Total amount of disk space free for the scheduler to allocate to tasks | Megabytes | Gauge |
nomad.client.allocated.network.<Device-Name>.<HostID> | Total amount of bandwidth the scheduler has allocated to tasks on the given device | Megabits | Gauge |
nomad.client.unallocated.network.<Device-Name>.<HostID> | Total amount of bandwidth free for the scheduler to allocate to tasks on the given device | Megabits | Gauge |
nomad.client.host.memory.<HostID>.total | Total amount of physical memory on the node | Bytes | Gauge |
nomad.client.host.memory.<HostID>.available | Total amount of memory available to processes which includes free and cached memory | Bytes | Gauge |
nomad.client.host.memory.<HostID>.used | Amount of memory used by processes | Bytes | Gauge |
nomad.client.host.memory.<HostID>.free | Amount of memory which is free | Bytes | Gauge |
nomad.client.uptime.<HostID> | Uptime of the host running the Nomad client | Seconds | Gauge |
nomad.client.host.cpu.<HostID>.<CPU-Core>.total | Total CPU utilization | Percentage | Gauge |
nomad.client.host.cpu.<HostID>.<CPU-Core>.user | CPU utilization in the user space | Percentage | Gauge |
nomad.client.host.cpu.<HostID>.<CPU-Core>.system | CPU utilization in the system space | Percentage | Gauge |
nomad.client.host.cpu.<HostID>.<CPU-Core>.idle | Idle time spent by the CPU | Percentage | Gauge |
nomad.client.host.disk.<HostID>.<Device-Name>.size | Total size of the device | Bytes | Gauge |
nomad.client.host.disk.<HostID>.<Device-Name>.used | Amount of space which has been used | Bytes | Gauge |
nomad.client.host.disk.<HostID>.<Device-Name>.available | Amount of space which is available | Bytes | Gauge |
nomad.client.host.disk.<HostID>.<Device-Name>.used_percent | Percentage of disk space used | Percentage | Gauge |
nomad.client.host.disk.<HostID>.<Device-Name>.inodes_percent | Disk space consumed by the inodes | Percent | Gauge |
Allocation Metrics
| Metric | Description | Unit | Type |
|---|---|---|---|
nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.rss | Amount of RSS memory consumed by the task | Bytes | Gauge |
nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.cache | Amount of memory cached by the task | Bytes | Gauge |
nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.swap | Amount of memory swapped by the task | Bytes | Gauge |
nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.max_usage | Maximum amount of memory ever used by the task | Bytes | Gauge |
nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.kernel_usage | Amount of memory used by the kernel for this task | Bytes | Gauge |
nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.memory.kernel_max_usage | Maximum amount of memory ever used by the kernel for this task | Bytes | Gauge |
nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.cpu.total_percent | Total CPU resources consumed by the task across all cores | Percentage | Gauge |
nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.cpu.system | Total CPU resources consumed by the task in the system space | Percentage | Gauge |
nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.cpu.user | Total CPU resources consumed by the task in the user space | Percentage | Gauge |
nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.cpu.throttled_time | Total time that the task was throttled | Nanoseconds | Gauge |
nomad.client.allocs.<Job>.<TaskGroup>.<AllocID>.<Task>.cpu.total_ticks | CPU ticks consumed by the process in the last collection interval | Integer | Gauge |
Job Summary Metrics
Job summary metrics are emitted by the Nomad leader server.
| Metric | Description | Unit | Type | Labels |
|---|---|---|---|---|
nomad.job_summary.queued | Number of queued allocations for a job | Integer | Gauge | job, task_group |
nomad.job_summary.complete | Number of complete allocations for a job | Integer | Gauge | job, task_group |
nomad.job_summary.failed | Number of failed allocations for a job | Integer | Gauge | job, task_group |
nomad.job_summary.running | Number of running allocations for a job | Integer | Gauge | job, task_group |
nomad.job_summary.starting | Number of starting allocations for a job | Integer | Gauge | job, task_group |
nomad.job_summary.lost | Number of lost allocations for a job | Integer | Gauge | job, task_group |
Job Status Metrics
Job status metrics are emitted by the Nomad leader server.
| Metric | Description | Unit | Type |
|---|---|---|---|
nomad.job_status.pending | Number jobs pending | Integer | Gauge |
nomad.job_status.running | Number jobs running | Integer | Gauge |
nomad.job_status.dead | Number of dead jobs | Integer | Gauge |
Metric Types
| Type | Description | Quantiles |
|---|---|---|
| Gauge | Gauge types report an absolute number at the end of the aggregation interval | false |
| Counter | Counts are incremented and flushed at the end of the aggregation interval and then are reset to zero | true |
| Timer | Timers measure the time to complete a task and will include quantiles, means, standard deviation, etc per interval. | true |
Tagged Metrics
As of version 0.7, Nomad will start emitting metrics in a tagged format. Each metric can support more than one tag, meaning that it is possible to do a match over metrics for datapoints such as a particular datacenter, and return all metrics with this tag. Nomad supports labels for namespaces as well.