[role="xpack"]
[testenv="platinum"]
[[ml-set-upgrade-mode]]
= Set upgrade mode API
++++
<titleabbrev>Set upgrade mode</titleabbrev>
++++

Sets a cluster wide upgrade_mode setting that prepares {ml} indices for an
upgrade. 

[[ml-set-upgrade-mode-request]]
== {api-request-title}
//////////////////////////

[source,console]
--------------------------------------------------
POST /_ml/set_upgrade_mode?enabled=false&timeout=10m
--------------------------------------------------
// TEARDOWN

//////////////////////////


`POST _ml/set_upgrade_mode`

[[ml-set-upgrade-mode-prereqs]]
== {api-prereq-title}

Requires the `manage_ml` cluster privilege. This privilege is included in the 
`machine_learning_admin` built-in role.

[[ml-set-upgrade-mode-desc]]
== {api-description-title}

When upgrading your cluster, in some circumstances you must restart your nodes and
reindex your {ml} indices. In those circumstances, there must be no {ml} jobs running. 
You can close the {ml} jobs, do the upgrade, then open all the jobs again. 
Alternatively, you can use this API to temporarily halt tasks associated 
with the jobs and {dfeeds} and prevent new jobs from opening. You can also use this 
API during upgrades that do not require you to reindex your {ml} indices, 
though stopping jobs is not a requirement in that case.

For more information, see {stack-ref}/upgrading-elastic-stack.html[Upgrading the {stack}].

When `enabled=true` this API temporarily halts all job and {dfeed} tasks and
prohibits new job and {dfeed} tasks from starting.

Subsequently, you can call the API with the enabled parameter set to false,
which causes {ml} jobs and {dfeeds} to return to their desired states.

You can see the current value for the `upgrade_mode` setting by using the
<<get-ml-info,get {ml} info API>>.

IMPORTANT:  No new {ml} jobs can be opened while the `upgrade_mode` setting is
`true`.

[[ml-set-upgrade-mode-query-parms]]
== {api-query-parms-title}

`enabled`::
  (Optional, Boolean) When `true`, this enables `upgrade_mode`. Defaults to
  `false`.

`timeout`::
  (Optional, time) The time to wait for the request to be completed. The default
  value is 30 seconds.

[[ml-set-upgrade-mode-example]]
== {api-examples-title}

[source,console]
--------------------------------------------------
POST _ml/set_upgrade_mode?enabled=true&timeout=10m
--------------------------------------------------

When the call is successful, an acknowledged response is returned. For example:

[source,console-result]
----
{
  "acknowledged": true
}
----

The acknowledged response will only be returned once all {ml} jobs and {dfeeds} have
finished writing to the {ml} internal indices. This means it is safe to reindex those
internal indices without causing failures. You must wait for the acknowledged
response before reindexing to ensure that all writes are completed.

When the upgrade is complete, you must set `upgrade_mode` to `false` for
{ml} jobs to start running again. For example:

[source,console]
--------------------------------------------------
POST _ml/set_upgrade_mode?enabled=false&timeout=10m
--------------------------------------------------
