[[ignore-malformed]]
=== `ignore_malformed`

Sometimes you don't have much control over the data that you receive.  One
user may send a `login` field that is a <<date,`date`>>, and another sends a
`login` field that is an email address.

Trying to index the wrong datatype into a field throws an exception by
default, and rejects the whole document.  The `ignore_malformed` parameter, if
set to `true`, allows the exception to be ignored.  The malformed field is not
indexed, but other fields in the document are processed normally.

For example:

[source,js]
--------------------------------------------------
PUT my_index
{
  "mappings": {
    "properties": {
      "number_one": {
        "type": "integer",
        "ignore_malformed": true
      },
      "number_two": {
        "type": "integer"
      }
    }
  }
}

PUT my_index/_doc/1
{
  "text":       "Some text value",
  "number_one": "foo" <1>
}

PUT my_index/_doc/2
{
  "text":       "Some text value",
  "number_two": "foo" <2>
}
--------------------------------------------------
// CONSOLE
// TEST[catch:bad_request]
<1> This document will have the `text` field indexed, but not the `number_one` field.
<2> This document will be rejected because `number_two` does not allow malformed values.

TIP: The `ignore_malformed` setting is allowed to have different settings for
fields of the same name in the same index.  Its value can be updated on
existing fields using the <<indices-put-mapping,PUT mapping API>>.


[[ignore-malformed-setting]]
==== Index-level default

The `index.mapping.ignore_malformed` setting can be set on the index level to
allow to ignore malformed content globally across all mapping types.

[source,js]
--------------------------------------------------
PUT my_index
{
  "settings": {
    "index.mapping.ignore_malformed": true <1>
  },
  "mappings": {
    "properties": {
      "number_one": { <1>
        "type": "byte"
      },
      "number_two": {
        "type": "integer",
        "ignore_malformed": false <2>
      }
    }
  }
}
--------------------------------------------------
// CONSOLE

<1> The `number_one` field inherits the index-level setting.
<2> The `number_two` field overrides the index-level setting to turn off `ignore_malformed`.

==== Dealing with malformed fields

Malformed fields are silently ignored at indexing time when `ignore_malformed`
is turned on. Whenever possible it is recommended to keep the number of
documents that have a malformed field contained, or queries on this field will
become meaningless. Elasticsearch makes it easy to check how many documents
have malformed fields by using `exist` or `term` queries on the special
<<mapping-ignored-field,`_ignored`>> field.