65 lines
1.8 KiB
Markdown
65 lines
1.8 KiB
Markdown
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---
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layout: "docs"
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page_title: "periodic Stanza - Job Specification"
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sidebar_current: "docs-job-specification-periodic"
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description: |-
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The "periodic" stanza allows a job to run at fixed times, dates, or intervals.
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The easiest way to think about the periodic scheduler is "Nomad cron" or
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"distributed cron".
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---
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# `periodic` Stanza
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<table class="table table-bordered table-striped">
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<tr>
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<th width="120">Placement</th>
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<td>
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<code>job -> **periodic**</code>
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</td>
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</tr>
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</table>
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The `periodic` stanza allows a job to run at fixed times, dates, or intervals.
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The easiest way to think about the periodic scheduler is "Nomad cron" or
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"distributed cron".
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```hcl
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job "docs" {
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periodic {
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cron = "*/15 * * * * *"
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prohibit_overlap = true
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}
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}
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```
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The periodic expression is always evaluated in the **UTC timezone** to ensure
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consistent evaluation when Nomad spans multiple time zones.
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## `periodic` Parameters
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- `cron` `(string: required)` - Specifies a cron expression configuring the
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interval to launch the job. In addition to [cron-specific formats][cron], this
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option also includes predefined expressions such as `@daily` or `@weekly`.
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- `prohibit_overlap` `(bool: false)` - Specifies if this job should wait until
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previous instances of this job have completed. This only applies to this job;
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it does not prevent other periodic jobs from running at the same time.
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## `periodic` Examples
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The following examples only show the `periodic` stanzas. Remember that the
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`periodic` Remember that the `periodic` stanza is only valid in the placements
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listed above.
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### Run Daily
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This example shows running a periodic job daily:
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```hcl
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periodic {
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cron = "@daily"
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}
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```
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[cron]: https://github.com/gorhill/cronexpr#implementation "List of cron expressions"
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