45 lines
1.7 KiB
Markdown
45 lines
1.7 KiB
Markdown
---
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layout: "docs"
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page_title: "Handling Signals - Operating a Job"
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sidebar_current: "docs-operating-a-job-updating-handling-signals"
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description: |-
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Well-behaved applications expose a way to perform cleanup prior to exiting.
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Nomad can optionally send a configurable signal to applications before
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killing them, allowing them to drain connections or gracefully terminate.
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---
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# Handling Signals
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On operating systems that support signals, Nomad will send the application a
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configurable signal before killing it. This gives the application time to
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gracefully drain connections and conduct other cleanup before shutting down.
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Certain applications take longer to drain than others, and thus Nomad allows
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specifying the amount of time to wait for the application to exit before
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force-killing it.
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Before Nomad terminates an application, it will send the `SIGINT` signal to the
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process. Processes running under Nomad should respond to this signal to
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gracefully drain connections. After a configurable timeout, the application
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will be force-terminated.
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For more details on the `kill_timeout` option, please see the
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[job specification documentation](/docs/job-specification/task.html#kill_timeout).
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```hcl
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job "docs" {
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group "example" {
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task "server" {
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# ...
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kill_timeout = "45s"
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}
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}
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}
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```
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The behavior is slightly different for Docker-based tasks. Nomad will run the
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`docker stop` command with the specified `kill_timeout`. The signal that `docker
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stop` sends to your container entrypoint is configurable using the
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[`STOPSIGNAL` configuration directive]
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(https://docs.docker.com/engine/reference/builder/#stopsignal), however please
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note that the default is `SIGTERM`.
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