Mapping limit settings

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Mapping limit settings

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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.

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 indices.query.bool.max_clause_count setting, which limits the maximum number of clauses in a query.

If your field mappings contain a large, arbitrary set of keys, consider using the 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: false. The fields that were not added to the mapping will be added to the _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.
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.
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.
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).
index.mapping.dimension_fields.limit
(Dynamic, integer) Maximum number of time series dimensions for the index. Defaults to 32768.