OpenSearch/docs/reference/migration/migrate_7_0/settings.asciidoc

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[[breaking_70_settings_changes]]
=== Settings changes

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==== The default for `node.name` is now the hostname

`node.name` now defaults to the hostname at the time when Elasticsearch
is started. Previously the default node name was the first eight characters
of the node id. It can still be configured explicitly in `elasticsearch.yml`.

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==== Percolator

* The deprecated `index.percolator.map_unmapped_fields_as_string` setting has been removed in favour of
  the `index.percolator.map_unmapped_fields_as_text` setting.

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==== Index thread pool

* Internally, single-document index/delete/update requests are executed as bulk
  requests with a single-document payload. This means that these requests are
  executed on the bulk thread pool. As such, the indexing thread pool is no
  longer needed and has been removed. As such, the  settings
  `thread_pool.index.size` and `thread_pool.index.queue_size` have been removed.

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[[write-thread-pool-fallback]]
==== Write thread pool fallback

* The bulk thread pool was replaced by the write thread pool in 6.3.0. However,
  for backwards compatibility reasons the name `bulk` was still usable as fallback
  settings `thread_pool.bulk.size` and `thread_pool.bulk.queue_size` for
  `thread_pool.write.size` and `thread_pool.write.queue_size`, respectively, and
  the system property `es.thread_pool.write.use_bulk_as_display_name` was
  available to keep the display output in APIs as `bulk` instead of `write`.
  These fallback settings and this system property have been removed.

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[[remove-http-enabled]]
==== Http enabled setting removed

* The setting `http.enabled` previously allowed disabling binding to HTTP, only allowing
use of the transport client. This setting has been removed, as the transport client
will be removed in the future, thus requiring HTTP to always be enabled.

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[[remove-http-pipelining-setting]]
==== Http pipelining setting removed

* The setting `http.pipelining` previously allowed disabling HTTP pipelining support.
This setting has been removed, as disabling http pipelining support on the server
provided little value. The setting `http.pipelining.max_events` can still be used to
limit the number of pipelined requests in-flight.

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==== Cross-cluster search settings renamed

The cross-cluster search remote cluster connection infrastructure is also used
in cross-cluster replication. This means that the setting names
`search.remote.*` used for configuring cross-cluster search belie the fact that
they also apply to other situations where a connection to a remote cluster as
used.  Therefore, these settings have been renamed from `search.remote.*` to
`cluster.remote.*`. For backwards compatibility purposes, we will fallback to
`search.remote.*` if `cluster.remote.*` is not set. For any such settings stored
in the cluster state, or set on dynamic settings updates, we will automatically
upgrade the setting from `search.remote.*` to `cluster.remote.*`. The fallback
settings will be removed in 8.0.0.

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[[include-realm-type-in-setting]]
==== Security realms settings

The settings for all security realms must now include the realm type as part
of the setting name, and the explicit `type` setting has been removed.

A realm that was previous configured as:
[source,yaml]
--------------------------------------------------
xpack.security.authc.realms:
  ldap1:
    type: ldap
    order: 1
    url: "ldaps://ldap.example.com/"
--------------------------------------------------

Must be migrated to: 
[source,yaml]
--------------------------------------------------
xpack.security.authc.realms:
  ldap.ldap1:
    order: 1
    url: "ldaps://ldap.example.com/"
--------------------------------------------------

Any realm specific secure settings that have been stored in the elasticsearch
keystore (such as ldap bind passwords, or passwords for ssl keys) must be updated
in a similar way.