mirror of
https://github.com/elastic/elasticsearch.git
synced 2025-04-25 07:37:19 -04:00
33a71e3289
* Remove `es-test-dir` book-scoped variable * Remove `plugins-examples-dir` book-scoped variable * Remove `:dependencies-dir:` and `:xes-repo-dir:` book-scoped variables - In `index.asciidoc`, two variables (`:dependencies-dir:` and `:xes-repo-dir:`) were removed. - In `sql/index.asciidoc`, the `:sql-tests:` path was updated to fuller path - In `esql/index.asciidoc`, the `:esql-tests:` path was updated idem * Replace `es-repo-dir` with `es-ref-dir` * Move `:include-xpack: true` to few files that use it, remove from index.asciidoc
61 lines
3.3 KiB
Text
61 lines
3.3 KiB
Text
[[mapping-settings-limit]]
|
|
== Mapping limit settings
|
|
Use the following settings to limit the number of field mappings (created manually or dynamically) and prevent documents from causing a mapping explosion:
|
|
|
|
`index.mapping.total_fields.limit`::
|
|
The maximum number of fields in an index. Field and object mappings, as well as
|
|
field aliases count towards this limit. Mapped runtime fields count towards this
|
|
limit as well. The default value is `1000`.
|
|
+
|
|
[IMPORTANT]
|
|
====
|
|
The limit is in place to prevent mappings and searches from becoming too
|
|
large. Higher values can lead to performance degradations and memory issues,
|
|
especially in clusters with a high load or few resources.
|
|
|
|
If you increase this setting, we recommend you also increase the
|
|
<<search-settings,`indices.query.bool.max_clause_count`>> setting, which
|
|
limits the maximum number of clauses in a query.
|
|
====
|
|
+
|
|
[TIP]
|
|
====
|
|
If your field mappings contain a large, arbitrary set of keys, consider using the <<flattened,flattened>> data type,
|
|
or setting the index setting `index.mapping.total_fields.ignore_dynamic_beyond_limit` to `true`.
|
|
====
|
|
|
|
`index.mapping.total_fields.ignore_dynamic_beyond_limit`::
|
|
This setting determines what happens when a dynamically mapped field would exceed the total fields limit.
|
|
When set to `false` (the default), the index request of the document that tries to add a dynamic field to the mapping will fail with the message `Limit of total fields [X] has been exceeded`.
|
|
When set to `true`, the index request will not fail.
|
|
Instead, fields that would exceed the limit are not added to the mapping, similar to <<dynamic, `dynamic: false`>>.
|
|
The fields that were not added to the mapping will be added to the <<mapping-ignored-field, `_ignored` field>>.
|
|
The default value is `false`.
|
|
|
|
`index.mapping.depth.limit`::
|
|
The maximum depth for a field, which is measured as the number of inner
|
|
objects. For instance, if all fields are defined at the root object level,
|
|
then the depth is `1`. If there is one object mapping, then the depth is
|
|
`2`, etc. Default is `20`.
|
|
|
|
// tag::nested-fields-limit[]
|
|
`index.mapping.nested_fields.limit`::
|
|
The maximum number of distinct `nested` mappings in an index. The `nested` type should only be used in special cases, when arrays of objects need to be queried independently of each other. To safeguard against poorly designed mappings, this setting
|
|
limits the number of unique `nested` types per index. Default is `50`.
|
|
// end::nested-fields-limit[]
|
|
|
|
// tag::nested-objects-limit[]
|
|
`index.mapping.nested_objects.limit`::
|
|
The maximum number of nested JSON objects that a single document can contain across all
|
|
`nested` types. This limit helps to prevent out of memory errors when a document contains too many nested
|
|
objects. Default is `10000`.
|
|
// end::nested-objects-limit[]
|
|
|
|
`index.mapping.field_name_length.limit`::
|
|
Setting for the maximum length of a field name. This setting isn't really something that addresses
|
|
mappings explosion but might still be useful if you want to limit the field length.
|
|
It usually shouldn't be necessary to set this setting. The default is okay
|
|
unless a user starts to add a huge number of fields with really long names. Default is
|
|
`Long.MAX_VALUE` (no limit).
|
|
|
|
include::{es-ref-dir}/data-streams/tsds-index-settings.asciidoc[tag=dimensions-limit]
|