elasticsearch/docs/reference/migration/migrate_8_0/settings.asciidoc

[discrete]
[[breaking_80_settings_changes]]
==== Settings changes

//NOTE: The notable-breaking-changes tagged regions are re-used in the
//Installation and Upgrade Guide

//tag::notable-breaking-changes[]
//end::notable-breaking-changes[]

[[search-remote-settings-removed]]
.The `search.remote.*` settings have been removed.
[%collapsible]
====
*Details* +
In 6.5 these settings were deprecated in favor of `cluster.remote`. In 7.x we
provided automatic upgrading of these settings to their `cluster.remote`
counterparts. In 8.0.0, these settings have been removed. Elasticsearch will
refuse to start if you have these settings in your configuration or cluster
state.

*Impact* +
Use the replacement `cluster.remote` settings. Discontinue use of the
`search.remote.*` settings. Specifying these settings in `elasticsearch.yml`
will result in an error on startup.
====

[[remove-pidfile]]
.The `pidfile` setting has been replaced by `node.pidfile`.
[%collapsible]
====
*Details* +
To ensure that all settings are in a proper namespace, the `pidfile` setting was
previously deprecated in version 7.4.0 of Elasticsearch, and is removed in
version 8.0.0. Instead, use `node.pidfile`.

*Impact* +
Use the `node.pidfile` setting. Discontinue use of the `pidfile` setting.
Specifying the `pidfile` setting in `elasticsearch.yml` will result in an error
on startup.
====

[[remove-processors]]
.The `processors` setting has been replaced by `node.processors`.
[%collapsible]
====
*Details* +
To ensure that all settings are in a proper namespace, the `processors` setting
was previously deprecated in version 7.4.0 of Elasticsearch, and is removed in
version 8.0.0. Instead, use `node.processors`.

*Impact* +
Use the `node.processors` setting. Discontinue use of the `processors` setting.
Specifying the `processors` setting in `elasticsearch.yml` will result in an
error on startup.
====

.The `node.processors` setting can no longer exceed the available number of processors.
[%collapsible]
====
*Details* +
Previously it was possible to set the number of processors used to set the
default sizes for the thread pools to be more than the number of available
processors. As this leads to more context switches and more threads but without
an increase in the number of physical CPUs on which to schedule these additional
threads, the `node.processors` setting is now bounded by the number of available
processors.

*Impact* +
If specified, ensure the value of `node.processors` setting does not exceed the
number of available processors. Setting the `node.processors` value greater than
the number of available processors in `elasticsearch.yml` will result in an
error on startup.
====

.The `cluster.remote.connect` setting has been removed.
[%collapsible]
====
*Details* +
In Elasticsearch 7.7.0, the setting `cluster.remote.connect` was deprecated in
favor of setting `node.remote_cluster_client`. In Elasticsearch 8.0.0, the
setting `cluster.remote.connect` is removed.

*Impact* +
Use the `node.remote_cluster_client` setting. Discontinue use of the
`cluster.remote.connect` setting. Specifying the `cluster.remote.connect`
setting in `elasticsearch.yml` will result in an error on startup.
====

.The `node.local_storage` setting has been removed.
[%collapsible]
====
*Details* +
In Elasticsearch 7.8.0, the setting `node.local_storage` was deprecated and
beginning in Elasticsearch 8.0.0 all nodes will require local storage. Therefore,
the `node.local_storage` setting has been removed.

*Impact* +
Discontinue use of the `node.local_storage` setting. Specifying this setting in
`elasticsearch.yml` will result in an error on startup.
====

.The `auth.password` setting for HTTP monitoring has been removed.
[%collapsible]
====
*Details* +
In Elasticsearch 7.7.0, the setting `xpack.monitoring.exporters.<exporterName>.auth.password`
was deprecated in favor of setting `xpack.monitoring.exporters.<exporterName>.auth.secure_password`.
In Elasticsearch 8.0.0, the setting `xpack.monitoring.exporters.<exporterName>.auth.password` is
removed.

*Impact* +
Use the `xpack.monitoring.exporters.<exporterName>.auth.secure_password`
setting. Discontinue use of the
`xpack.monitoring.exporters.<exporterName>.auth.password` setting. Specifying
the `xpack.monitoring.exporters.<exporterName>.auth.password` setting in
`elasticsearch.yml` will result in an error on startup.
====

.Settings used to disable basic license features have been removed.
[%collapsible]
====
*Details* +
The following settings were deprecated in {es} 7.8.0 and have been removed
in {es} 8.0.0:

* `xpack.enrich.enabled`
* `xpack.flattened.enabled`
* `xpack.ilm.enabled`
* `xpack.monitoring.enabled`
* `xpack.rollup.enabled`
* `xpack.slm.enabled`
* `xpack.sql.enabled`
* `xpack.transform.enabled`
* `xpack.vectors.enabled`

These basic license features are now always enabled.

If you have disabled ILM so that you can use another tool to manage Watcher
indices, the newly introduced `xpack.watcher.use_ilm_index_management` setting
may be set to false.

*Impact* +
Discontinue use of the removed settings. Specifying these settings in
`elasticsearch.yml` will result in an error on startup.
====

.Settings used to defer cluster recovery pending a certain number of master nodes have been removed.
[%collapsible]
====
*Details* +
The following settings were deprecated in {es} 7.8.0 and have been removed in
{es} 8.0.0:

* `gateway.expected_nodes`
* `gateway.expected_master_nodes`
* `gateway.recover_after_nodes`
* `gateway.recover_after_master_nodes`

It is safe to recover the cluster as soon as a majority of master-eligible
nodes have joined so there is no benefit in waiting for any additional
master-eligible nodes to start.

*Impact* +
Discontinue use of the removed settings. If needed, use
`gateway.expected_data_nodes` or `gateway.recover_after_data_nodes` to defer
cluster recovery pending a certain number of data nodes.
====

.You can no longer set `xpack.searchable.snapshot.shared_cache.size` on non-frozen nodes.
[%collapsible]
====
*Details* +
Setting `xpack.searchable.snapshot.shared_cache.size` to be positive on a node
that does not have the `data_frozen` role was deprecated in {es} 7.12.0 and has
been removed in {es} 8.0.0.

*Impact* +
{es} only allocates partially mounted indices to nodes with the `data_frozen`
role. Do not set `xpack.searchable.snapshot.shared_cache.size` on nodes without
the `data_frozen` role. Removing the setting on nodes without the `data_frozen`
role will not impact functionality.
====

.By default, destructive index actions do not allow wildcards.
[%collapsible]
====
*Details* +
The default value of the setting `action.destructive_requires_name` changes from `false`
to `true` in {es} 8.0.0.

In previous versions, the default setting allowed users to use wildcard
patterns to delete, close, or change index blocks on indices. In order
to prevent the accidental deletion of indices that happen to match a
wildcard pattern, we now require, by default, that any such destructive
operation explicitly name the indices it intends to modify.

*Impact* +
If you would like to use wildcard patterns for destructive actions, set
`action.destructive_requires_name` to `false` using the <<cluster-update-settings,
cluster settings>> API.
====

.Legacy role settings have been removed.
[%collapsible]
====
*Details* +
The legacy role settings:

* `node.data`
* `node.ingest`
* `node.master`
* `node.ml`
* `node.remote_cluster_client`
* `node.transform`
* `node.voting_only`

have been removed. Instead, use the `node.roles` setting. If you were previously
using the legacy role settings on a 7.13 or later cluster, you will have a
deprecation log message on each of your nodes indicating the exact replacement
value for `node.roles`.

*Impact* +
Discontinue use of the removed settings. Specifying these settings in
`elasticsearch.yml` will result in an error on startup.
====

[[system-call-filter-setting]]
.System call filter setting removed
[%collapsible]
====
*Details* +
Elasticsearch uses system call filters to remove its ability to fork another
process. This is useful to mitigate remote code exploits. These system call
filters are enabled by default, and were previously controlled via the setting
`bootstrap.system_call_filter`. Starting in Elasticsearch 8.0, system call
filters will be required. As such, the setting `bootstrap.system_call_filter`
was deprecated in Elasticsearch 7.13.0, and is removed as of Elasticsearch
8.0.0.

*Impact* +
Discontinue use of the removed setting. Specifying this setting in Elasticsearch
configuration will result in an error on startup.
====

[[tier-filter-setting]]
.Tier filtering settings removed
[%collapsible]
====
*Details* +
The cluster and index level settings ending in `._tier` used for filtering the allocation of a shard
to a particular set of nodes have been removed. Instead, the <<tier-preference-allocation-filter,
tier preference setting>>, `index.routing.allocation.include._tier_preference` should be used. The
removed settings are:

Cluster level settings:
- `cluster.routing.allocation.include._tier`
- `cluster.routing.allocation.exclude._tier`
- `cluster.routing.allocation.require._tier`
Index settings:
- `index.routing.allocation.include._tier`
- `index.routing.allocation.exclude._tier`
- `index.routing.allocation.require._tier`

*Impact* +
Discontinue use of the removed settings. Specifying any of these cluster settings in Elasticsearch
configuration will result in an error on startup. Any indices using these settings will have the
settings archived (and they will have no effect) when the index metadata is loaded.

[[shared-data-path-setting]]
.Shared data path and per index data path settings deprecated
[%collapsible]
====
*Details* +
Elasticsearch uses the shared data path as the base path of per index data
paths. This feature was previously used with shared replicas. Starting in
7.13.0, these settings are deprecated. Starting in 8.0 only existing
indices created in 7.x will be capable of using the shared data path and
per index data path settings.

*Impact* +
Discontinue use of the deprecated settings.

[[single-data-node-watermark-setting]]
.Single data node watermark setting only accept true and is deprecated
[%collapsible]
====
*Details* +
In 7.14, setting `cluster.routing.allocation.disk.watermark.enable_for_single_data_node`
to false was deprecated. Starting in 8.0, the only legal value will be
true. In a future release, the setting will be removed completely, with same
behavior as if the setting was `true`.

If the old behavior is desired for a single data node cluster, disk based
allocation can be disabled by setting
`cluster.routing.allocation.disk.threshold_enabled: false`

*Impact* +
Discontinue use of the deprecated setting.
====