OpenSearch/docs/reference/cluster/voting-exclusions.asciidoc

[[voting-config-exclusions]]
=== Voting configuration exclusions API
++++
<titleabbrev>Voting configuration exclusions</titleabbrev>
++++

Adds or removes master-eligible nodes from the
<<modules-discovery-voting,voting configuration exclusion list>>.


[[voting-config-exclusions-api-request]]
==== {api-request-title}

`POST _cluster/voting_config_exclusions?node_names=<node_names>` +

`POST _cluster/voting_config_exclusions?node_ids=<node_ids>` +

`DELETE _cluster/voting_config_exclusions`


[[voting-config-exclusions-api-desc]]
==== {api-description-title}
  
By default, if there are more than three master-eligible nodes in the cluster
and you remove fewer than half of the master-eligible nodes in the cluster at
once, the <<modules-discovery-voting,voting configuration>> automatically
shrinks.

If you want to shrink the voting configuration to contain fewer than three nodes
or to remove half or more of the master-eligible nodes in the cluster at once,
you must use this API to remove departed nodes from the voting configuration
manually. It adds an entry for that node in the voting configuration exclusions
list. The cluster then tries to reconfigure the voting configuration to remove
that node and to prevent it from returning.

If the API fails, you can safely retry it.  Only a successful response
guarantees that the node has been removed from the voting configuration and will
not be reinstated.

NOTE: Voting exclusions are required only when you remove at least half of the
master-eligible nodes from a cluster in a short time period. They are not
required when removing master-ineligible nodes or fewer than half of the
master-eligible nodes.

For more information, see <<modules-discovery-removing-nodes>>.

[[voting-config-exclusions-api-query-params]]
==== {api-query-parms-title}

`node_names`::
A comma-separated list of the names of the nodes to exclude from the voting
configuration. If specified, you may not also specify `?node_ids`.

`node_ids`::
A comma-separated list of the persistent ids of the nodes to exclude from the
voting configuration. If specified, you may not also specify `?node_names`.

`timeout`::
(Optional, <<time-units, time units>>) When adding a voting configuration
exclusion, the API waits for the specified nodes to be excluded from the voting
configuration before returning. The period of time to wait is specified by the
`?timeout` query parameter. If the timeout expires before the appropriate
condition is satisfied, the request fails and returns an error. Defaults to
`30s`.

`wait_for_removal`::
(Optional, boolean) Specifies whether to wait for all excluded nodes to be
removed from the cluster before clearing the voting configuration exclusions
list. Defaults to `true`, meaning that all excluded nodes must be removed from
the cluster before this API takes any action. If set to `false` then the voting
configuration exclusions list is cleared even if some excluded nodes are still
in the cluster.
  
[[voting-config-exclusions-api-example]]
==== {api-examples-title}

Adds nodes named `nodeName1` and `nodeName2` to the voting configuration
exclusions list:

[source,console]
-------------------------------------------------- 
POST /_cluster/voting_config_exclusions?node_names=nodeName1,nodeName2
--------------------------------------------------

Remove all exclusions from the list:

[source,console]
--------------------------------------------------
DELETE /_cluster/voting_config_exclusions
--------------------------------------------------