a6e0d17433
* update `restart` documentation #7288 added support for task-specific `restart` policy. this PR updates the docs to reflect that. * added an explicit example of task-specific restart policy * Update website/pages/docs/job-specification/restart.mdx
125 lines
3.2 KiB
Plaintext
125 lines
3.2 KiB
Plaintext
---
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layout: docs
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page_title: restart Stanza - Job Specification
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sidebar_title: restart
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description: The "restart" stanza configures a group's behavior on task failure.
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---
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# `restart` Stanza
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<Placement
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groups={[
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['job', 'group', 'restart'],
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['job', 'group', 'task', 'restart']
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]}
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/>
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The `restart` stanza configures a tasks's behavior on task failure. Restarts
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happen on the client that is running the task.
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```hcl
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job "docs" {
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group "example" {
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restart {
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attempts = 3
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delay = "30s"
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}
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}
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}
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```
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If specified at the group level, the configuration is inherited by all
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tasks in the group. If present on the task, the policy is merged with
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the restart policy from the encapsulating task group.
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For example, assuming that the task group restart policy is:
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```hcl
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restart {
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interval = "30m"
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attempts = 2
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delay = "15s"
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mode = "fail"
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}
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```
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and the individual task restart policy is:
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```hcl
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restart {
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attempts = 5
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}
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```
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then the effective restart policy for the task will be:
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```hcl
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restart {
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interval = "30m"
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attempts = 5
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delay = "15s"
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mode = "fail"
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}
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```
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## `restart` Parameters
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- `attempts` `(int: <varies>)` - Specifies the number of restarts allowed in the
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configured interval. Defaults vary by job type, see below for more
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information.
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- `delay` `(string: "15s")` - Specifies the duration to wait before restarting a
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task. This is specified using a label suffix like "30s" or "1h". A random
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jitter of up to 25% is added to the delay.
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- `interval` `(string: <varies>)` - Specifies the duration which begins when the
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first task starts and ensures that only `attempts` number of restarts happens
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within it. If more than `attempts` number of failures happen, behavior is
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controlled by `mode`. This is specified using a label suffix like "30s" or
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"1h". Defaults vary by job type, see below for more information.
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- `mode` `(string: "fail")` - Controls the behavior when the task fails more
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than `attempts` times in an interval. For a detailed explanation of these
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values and their behavior, please see the [mode values section](#mode-values).
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### `restart` Parameter Defaults
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The values for many of the `restart` parameters vary by job type. Here are the
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defaults by job type:
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- The default batch restart policy is:
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```hcl
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restart {
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attempts = 3
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delay = "15s"
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interval = "24h"
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mode = "fail"
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}
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```
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- The default service and system job restart policy is:
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```hcl
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restart {
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interval = "30m"
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attempts = 2
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delay = "15s"
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mode = "fail"
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}
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```
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### `mode` Values
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This section details the specific values for the "mode" parameter in the Nomad
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job specification for constraints. The mode is always specified as a string
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```hcl
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restart {
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mode = "..."
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}
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```
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- `"delay"` - Instructs the scheduler to delay the next restart until the next
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`interval` is reached.
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- `"fail"` - Instructs the scheduler to not attempt to restart the task on
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failure. This is the default behavior. This mode is useful for non-idempotent jobs which are unlikely to
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succeed after a few failures. Failed jobs will be restarted according to
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the [`reschedule`](/docs/job-specification/reschedule) stanza.
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