github.com/Ilhicas/nomad@v1.0.4-0.20210304152020-e86851182bc3/website/content/docs/commands/node/drain.mdx (about) 1 --- 2 layout: docs 3 page_title: 'Commands: node drain' 4 sidebar_title: drain 5 description: | 6 The node drain command is used to configure a node's drain strategy. 7 --- 8 9 # Command: node drain 10 11 The `node drain` command is used to toggle drain mode on a given node. Drain 12 mode prevents any new tasks from being allocated to the node, and begins 13 migrating all existing allocations away. Allocations will be migrated according 14 to their [`migrate`][migrate] stanza until the drain's deadline is reached. 15 16 By default the `node drain` command blocks until a node is done draining and 17 all allocations have terminated. Canceling the `node drain` command _will not_ 18 cancel the drain. Drains may be canceled by using the `-disable` parameter 19 below. 20 21 When draining more than one node at a time, it is recommended you first 22 disable [scheduling eligibility][eligibility] on all nodes that will be 23 drained. For example if you are decommissioning an entire class of nodes, 24 first run `node eligibility -disable` on all of their node IDs, and then run 25 `node drain -enable`. This will ensure allocations drained from the first node 26 are not placed on another node about to be drained. 27 28 The [node status] command compliments this nicely by providing the current drain 29 status of a given node. 30 31 See the [Workload Migration guide] for detailed examples of node draining. 32 33 ## Usage 34 35 ```plaintext 36 nomad node drain [options] <node> 37 ``` 38 39 A `-self` flag can be used to drain the local node. If this is not supplied, a 40 node ID or prefix must be provided. If there is an exact match, the drain mode 41 will be adjusted for that node. Otherwise, a list of matching nodes and 42 information will be displayed. 43 44 It is also required to pass one of `-enable` or `-disable`, depending on which 45 operation is desired. 46 47 If ACLs are enabled, this option requires a token with the 'node:write' 48 capability. 49 50 ## General Options 51 52 @include 'general_options_no_namespace.mdx' 53 54 ## Drain Options 55 56 - `-enable`: Enable node drain mode. 57 58 - `-disable`: Disable node drain mode. 59 60 - `-deadline`: Set the deadline by which all allocations must be moved off the 61 node. Remaining allocations after the deadline are force removed from the 62 node. Defaults to 1 hour. 63 64 - `-detach`: Return immediately instead of entering monitor mode. 65 66 - `-monitor`: Enter monitor mode directly without modifying the drain status. 67 68 - `-force`: Force remove allocations off the node immediately. 69 70 - `-no-deadline`: No deadline allows the allocations to drain off the node 71 without being force stopped after a certain deadline. 72 73 - `-ignore-system`: Ignore system allows the drain to complete without 74 stopping system job allocations. By default system jobs are stopped 75 last. You should always use this flag when draining a node running 76 [CSI node plugins][internals-csi]. 77 78 - `-keep-ineligible`: Keep ineligible will maintain the node's scheduling 79 ineligibility even if the drain is being disabled. This is useful when an 80 existing drain is being cancelled but additional scheduling on the node is not 81 desired. 82 83 - `-self`: Drain the local node. 84 85 - `-yes`: Automatic yes to prompts. 86 87 ## Examples 88 89 Enable drain mode on node with ID prefix "4d2ba53b": 90 91 ```shell-session 92 $ nomad node drain -enable f4e8a9e5 93 Are you sure you want to enable drain mode for node "f4e8a9e5-30d8-3536-1e6f-cda5c869c35e"? [y/N] y 94 2018-03-30T23:13:16Z: Ctrl-C to stop monitoring: will not cancel the node drain 95 2018-03-30T23:13:16Z: Node "f4e8a9e5-30d8-3536-1e6f-cda5c869c35e" drain strategy set 96 2018-03-30T23:13:17Z: Alloc "1877230b-64d3-a7dd-9c31-dc5ad3c93e9a" marked for migration 97 2018-03-30T23:13:17Z: Alloc "1877230b-64d3-a7dd-9c31-dc5ad3c93e9a" draining 98 2018-03-30T23:13:17Z: Alloc "1877230b-64d3-a7dd-9c31-dc5ad3c93e9a" status running -> complete 99 2018-03-30T23:13:29Z: Alloc "3fce5308-818c-369e-0bb7-f61f0a1be9ed" marked for migration 100 2018-03-30T23:13:29Z: Alloc "3fce5308-818c-369e-0bb7-f61f0a1be9ed" draining 101 2018-03-30T23:13:30Z: Alloc "3fce5308-818c-369e-0bb7-f61f0a1be9ed" status running -> complete 102 2018-03-30T23:13:41Z: Alloc "9a98c5aa-a719-2f34-ecfc-0e6268b5d537" marked for migration 103 2018-03-30T23:13:41Z: Alloc "9a98c5aa-a719-2f34-ecfc-0e6268b5d537" draining 104 2018-03-30T23:13:41Z: Node "f4e8a9e5-30d8-3536-1e6f-cda5c869c35e" has marked all allocations for migration 105 2018-03-30T23:13:42Z: Alloc "9a98c5aa-a719-2f34-ecfc-0e6268b5d537" status running -> complete 106 2018-03-30T23:13:42Z: All allocations on node "f4e8a9e5-30d8-3536-1e6f-cda5c869c35e" have stopped. 107 ``` 108 109 Enable drain mode on the local node: 110 111 ```shell-session 112 $ nomad node drain -enable -self 113 ... 114 ``` 115 116 Enable drain mode but do not stop system jobs: 117 118 ```shell-session 119 $ nomad node drain -enable -ignore-system 4d2ba53b 120 ... 121 ``` 122 123 Disable drain mode but keep the node ineligible for scheduling. Useful for 124 inspecting the current state of a misbehaving node without Nomad trying to 125 start or migrate allocations: 126 127 ```shell-session 128 $ nomad node drain -disable -keep-ineligible 4d2ba53b 129 ... 130 ``` 131 132 Enable drain mode and detach from monitoring, then reattach later: 133 134 ```shell-session 135 $ nomad node drain -enable -detach -self 136 ... 137 $ nomad node drain -self -monitor 138 ... 139 ``` 140 141 [eligibility]: /docs/commands/node/eligibility 142 [migrate]: /docs/job-specification/migrate 143 [node status]: /docs/commands/node/status 144 [workload migration guide]: https://learn.hashicorp.com/tutorials/nomad/node-drain 145 [internals-csi]: /docs/internals/plugins/csi