github.com/taylorchu/nomad@v0.5.3-rc1.0.20170407200202-db11e7dd7b55/website/source/docs/operating-a-job/resource-utilization.html.md (about)

     1  ---
     2  layout: "docs"
     3  page_title: "Resource Utilization - Operating a Job"
     4  sidebar_current: "docs-operating-a-job-resource-utilization"
     5  description: |-
     6    Nomad supports reporting detailed job statistics and resource utilization
     7    metrics for most task drivers. This section describes the ways to inspect a
     8    job's resource consumption and utilization.
     9  ---
    10  
    11  # Resource Utilization
    12  
    13  Understanding the resource utilization of an application is important, and Nomad
    14  supports reporting detailed statistics in many of its drivers. The main
    15  interface for seeing resource utilization is the `alloc-status` command with the
    16  `-stats` flag.
    17  
    18  This section will utilize the job named "docs" from the [previous
    19  sections](/docs/operating-a-job/submitting-jobs.html), but these operations
    20  and command largely apply to all jobs in Nomad.
    21  
    22  As a reminder, here is the output of the run command from the previous example:
    23  
    24  ```text
    25  $ nomad run docs.nomad
    26  ==> Monitoring evaluation "42d788a3"
    27      Evaluation triggered by job "docs"
    28      Allocation "04d9627d" created: node "a1f934c9", group "example"
    29      Allocation "e7b8d4f5" created: node "012ea79b", group "example"
    30      Allocation "5cbf23a1" modified: node "1e1aa1e0", group "example"
    31      Evaluation status changed: "pending" -> "complete"
    32  ==> Evaluation "42d788a3" finished with status "complete"
    33  ```
    34  
    35  To see the detailed usage statistics, we can issue the command:
    36  
    37  ```shell
    38  $ nomad alloc-status -stats 04d9627d
    39  ```
    40  
    41  And here is some sample output:
    42  
    43  ```text
    44  $ nomad alloc-status c3e0
    45  ID            = 04d9627d
    46  Eval ID       = 42d788a3
    47  Name          = docs.example[2]
    48  Node ID       = a1f934c9
    49  Job ID        = docs
    50  Client Status = running
    51  
    52  Task "server" is "running"
    53  Task Resources
    54  CPU        Memory          Disk     IOPS  Addresses
    55  75/100 MHz  784 KiB/10 MiB  300 MiB  0     http: 10.1.1.196:5678
    56  
    57  Memory Stats
    58  Cache   Max Usage  RSS      Swap
    59  56 KiB  1.3 MiB    784 KiB  0 B
    60  
    61  CPU Stats
    62  Percent  Throttled Periods  Throttled Time
    63  0.00%    0                  0
    64  
    65  Recent Events:
    66  Time         Type      Description
    67  <timestamp>  Started   Task started by client
    68  <timestamp>  Received  Task received by client
    69  ```
    70  
    71  Here we can see that we are near the limit of our configured CPU but we have
    72  plenty of memory headroom. We can use this information to alter our job's
    73  resources to better reflect is actually needs:
    74  
    75  ```hcl
    76  resource {
    77    cpu    = 200
    78    memory = 10
    79  }
    80  ```
    81  
    82  Adjusting resources is very important for a variety of reasons:
    83  
    84  * Ensuring your application does not get OOM killed if it hits its memory limit.
    85  * Ensuring the application performs well by ensuring it has some CPU allowance.
    86  * Optimizing cluster density by reserving what you need and not over-allocating.
    87  
    88  While single point in time resource usage measurements are useful, it is often
    89  more useful to graph resource usage over time to better understand and estimate
    90  resource usage. Nomad supports outputting resource data to statsite and statsd
    91  and is the recommended way of monitoring resources. For more information about
    92  outputting telemetry see the [telemetry
    93  documentation](/docs/agent/telemetry.html).
    94  
    95  For more advanced use cases, the resource usage data is also accessible via the
    96  client's HTTP API. See the documentation of the Client's [allocation HTTP
    97  API](/docs/http/client-allocation-stats.html).