github.com/maier/nomad@v0.4.1-0.20161110003312-a9e3d0b8549d/website/source/docs/job-specification/periodic.html.md (about)

     1  ---
     2  layout: "docs"
     3  page_title: "periodic Stanza - Job Specification"
     4  sidebar_current: "docs-job-specification-periodic"
     5  description: |-
     6    The "periodic" stanza allows a job to run at fixed times, dates, or intervals.
     7    The easiest way to think about the periodic scheduler is "Nomad cron" or
     8    "distributed cron".
     9  ---
    10  
    11  # `periodic` Stanza
    12  
    13  <table class="table table-bordered table-striped">
    14    <tr>
    15      <th width="120">Placement</th>
    16      <td>
    17        <code>job -> **periodic**</code>
    18      </td>
    19    </tr>
    20  </table>
    21  
    22  The `periodic` stanza allows a job to run at fixed times, dates, or intervals.
    23  The easiest way to think about the periodic scheduler is "Nomad cron" or
    24  "distributed cron".
    25  
    26  ```hcl
    27  job "docs" {
    28    periodic {
    29      cron             = "*/15 * * * * *"
    30      prohibit_overlap = true
    31    }
    32  }
    33  ```
    34  
    35  The periodic expression is always evaluated in the **UTC timezone** to ensure
    36  consistent evaluation when Nomad spans multiple time zones.
    37  
    38  ## `periodic` Parameters
    39  
    40  - `cron` `(string: <required>)` - Specifies a cron expression configuring the
    41    interval to launch the job. In addition to [cron-specific formats][cron], this
    42    option also includes predefined expressions such as `@daily` or `@weekly`.
    43  
    44  - `prohibit_overlap` `(bool: false)` - Specifies if this job should wait until
    45    previous instances of this job have completed. This only applies to this job;
    46    it does not prevent other periodic jobs from running at the same time.
    47  
    48  ## `periodic` Examples
    49  
    50  The following examples only show the `periodic` stanzas. Remember that the
    51  `periodic` stanza is only valid in the placements listed above.
    52  
    53  ### Run Daily
    54  
    55  This example shows running a periodic job daily:
    56  
    57  ```hcl
    58  periodic {
    59    cron = "@daily"
    60  }
    61  ```
    62  
    63  [cron]: https://github.com/gorhill/cronexpr#implementation "List of cron expressions"