Mapping limit settings
editMapping limit settings
editUse 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
totrue
. -
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 messageLimit of total fields [X] has been exceeded
. When set totrue
, the index request will not fail. Instead, fields that would exceed the limit are not added to the mapping, similar todynamic: false
. The fields that were not added to the mapping will be added to the_ignored
field. The default value isfalse
. -
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 is2
, etc. Default is20
.
-
index.mapping.nested_fields.limit
-
The maximum number of distinct
nested
mappings in an index. Thenested
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 uniquenested
types per index. Default is50
.
-
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 is10000
. -
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
.