120 lines
4.7 KiB
Plaintext
120 lines
4.7 KiB
Plaintext
---
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layout: "docs"
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page_title: "Commands: node drain"
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sidebar_current: "docs-commands-node-drain"
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description: >
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The node drain command is used to configure a node's drain strategy.
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---
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# Command: node drain
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The `node drain` command is used to toggle drain mode on a given node. Drain
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mode prevents any new tasks from being allocated to the node, and begins
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migrating all existing allocations away. Allocations will be migrated according
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to their [`migrate`][migrate] stanza until the drain's deadline is reached.
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By default the `node drain` command blocks until a node is done draining and
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all allocations have terminated. Canceling the `node drain` command *will not*
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cancel the drain. Drains may be canceled by using the `-disable` parameter
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below.
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When draining more than one node at a time, it is recommended you first disable
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[scheduling eligibility][eligibility] on all nodes that will be drained. For
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example if you are decommissioning an entire class of nodes, first run `node
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eligibility -disable` on all of their node IDs, and then run `node drain
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-enable`. This will ensure allocations drained from the first node are not
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placed on another node about to be drained.
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The [node status](/docs/commands/node/status.html) command compliments this
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nicely by providing the current drain status of a given node.
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See the [Decommissioning Nodes guide](/guides/node-draining.html) for detailed
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examples of node draining.
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## Usage
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```
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nomad node drain [options] <node>
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```
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A `-self` flag can be used to drain the local node. If this is not supplied, a
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node ID or prefix must be provided. If there is an exact match, the drain mode
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will be adjusted for that node. Otherwise, a list of matching nodes and
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information will be displayed.
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It is also required to pass one of `-enable` or `-disable`, depending on which
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operation is desired.
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## General Options
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<%= partial "docs/commands/_general_options" %>
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## Drain Options
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* `-enable`: Enable node drain mode.
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* `-disable`: Disable node drain mode.
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* `-deadline`: Set the deadline by which all allocations must be moved off the
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node. Remaining allocations after the deadline are force removed from the
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node. Defaults to 1 hour.
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* `-detach`: Return immediately instead of entering monitor mode.
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* `-force`: Force remove allocations off the node immediately.
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* `-no-deadline`: No deadline allows the allocations to drain off the node
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without being force stopped after a certain deadline.
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* `-ignore-system`: Ignore system allows the drain to complete without stopping
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system job allocations. By default system jobs are stopped last.
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* `-keep-ineligible`: Keep ineligible will maintain the node's scheduling
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ineligibility even if the drain is being disabled. This is useful when an
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existing drain is being cancelled but additional scheduling on the node is not
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desired.
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* `-self`: Drain the local node.
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* `-yes`: Automatic yes to prompts.
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## Examples
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Enable drain mode on node with ID prefix "4d2ba53b":
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```
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$ nomad node drain -enable f4e8a9e5
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Are you sure you want to enable drain mode for node "f4e8a9e5-30d8-3536-1e6f-cda5c869c35e"? [y/N] y
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2018-03-30T23:13:16Z: Ctrl-C to stop monitoring: will not cancel the node drain
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2018-03-30T23:13:16Z: Node "f4e8a9e5-30d8-3536-1e6f-cda5c869c35e" drain strategy set
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2018-03-30T23:13:17Z: Alloc "1877230b-64d3-a7dd-9c31-dc5ad3c93e9a" marked for migration
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2018-03-30T23:13:17Z: Alloc "1877230b-64d3-a7dd-9c31-dc5ad3c93e9a" draining
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2018-03-30T23:13:17Z: Alloc "1877230b-64d3-a7dd-9c31-dc5ad3c93e9a" status running -> complete
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2018-03-30T23:13:29Z: Alloc "3fce5308-818c-369e-0bb7-f61f0a1be9ed" marked for migration
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2018-03-30T23:13:29Z: Alloc "3fce5308-818c-369e-0bb7-f61f0a1be9ed" draining
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2018-03-30T23:13:30Z: Alloc "3fce5308-818c-369e-0bb7-f61f0a1be9ed" status running -> complete
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2018-03-30T23:13:41Z: Alloc "9a98c5aa-a719-2f34-ecfc-0e6268b5d537" marked for migration
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2018-03-30T23:13:41Z: Alloc "9a98c5aa-a719-2f34-ecfc-0e6268b5d537" draining
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2018-03-30T23:13:41Z: Node "f4e8a9e5-30d8-3536-1e6f-cda5c869c35e" has marked all allocations for migration
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2018-03-30T23:13:42Z: Alloc "9a98c5aa-a719-2f34-ecfc-0e6268b5d537" status running -> complete
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2018-03-30T23:13:42Z: All allocations on node "f4e8a9e5-30d8-3536-1e6f-cda5c869c35e" have stopped.
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```
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Enable drain mode on the local node:
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```
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$ nomad node drain -enable -self
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...
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```
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Enable drain mode but do not stop system jobs:
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```
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$ nomad node drain -enable -ignore-system 4d2ba53b
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...
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```
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Disable drain mode but keep the node ineligible for scheduling. Useful for
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inspecting the current state of a misbehaving node without Nomad trying to
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start or migrate allocations:
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```
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$ nomad node drain -disable -keep-ineligible 4d2ba53b
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...
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```
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[eligibility]: /docs/commands/node/eligibility.html
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[migrate]: /docs/job-specification/migrate.html
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