[role="xpack"]
[[inference-processor]]
=== {infer-cap} processor
++++
<titleabbrev>{infer-cap}</titleabbrev>
++++


Uses a pre-trained {dfanalytics} model or a model deployed for natural
language processing tasks to infer against the data that is being
ingested in the pipeline.


[[inference-options]]
.{infer-cap} Options
[options="header"]
|======
| Name                                  | Required  | Default                                    | Description
| `model_id` .                          | yes       | -                                          | (String) The ID or alias for the trained model, or the ID of the deployment.
| `input_output`                        | no        | -                                          | (List) Input fields for {infer} and output (destination) fields for the {infer} results. This option is incompatible with the `target_field` and `field_map` options.
| `target_field`                        | no        | `ml.inference.<processor_tag>`             | (String) Field added to incoming documents to contain results objects.
| `field_map`                           | no        | If defined the model's default field map   | (Object) Maps the document field names to the known field names of the model. This mapping takes precedence over any default mappings provided in the model configuration.
| `inference_config`                    | no        | The default settings defined in the model  | (Object) Contains the inference type and its options.
| `ignore_missing`                      | no        | `false`                                    | (Boolean) If `true` and any of the input fields defined in `input_ouput` are missing then those missing fields are quietly ignored, otherwise a missing field causes a failure. Only applies when using `input_output` configurations to explicitly list the input fields.
include::common-options.asciidoc[]
|======

[IMPORTANT]
==================================================
* You cannot use the `input_output` field with the `target_field` and 
`field_map` fields. For NLP models, use the `input_output` option. For 
{dfanalytics} models, use the `target_field` and `field_map` option.
* Each {infer} input field must be single strings, not arrays of strings.
* The `input_field` is processed as is and ignores any <<mapping,index mapping>>'s <<analysis,analyzers>> at time of {infer} run.
==================================================

[discrete]
[[inference-input-output-example]]
==== Configuring input and output fields

Select the `content` field for inference and write the result to 
`content_embedding`.

IMPORTANT: If the specified `output_field` already exists in the ingest document, it won't be overwritten.
The {infer} results will be appended to the existing fields within `output_field`, which could lead to duplicate fields and potential errors.
To avoid this, use an unique `output_field` field name that does not clash with any existing fields.


[source,js]
--------------------------------------------------
{
  "inference": {
    "model_id": "model_deployment_for_inference",
    "input_output": [
        {
            "input_field": "content",
            "output_field": "content_embedding"
        }
    ]
  }
}
--------------------------------------------------
// NOTCONSOLE

==== Configuring multiple inputs

The `content` and `title` fields will be read from the incoming document and 
sent to the model for the inference. The inference output is written to 
`content_embedding` and `title_embedding` respectively.

[source,js]
--------------------------------------------------
{
  "inference": {
    "model_id": "model_deployment_for_inference",
    "input_output": [
        {
            "input_field": "content",
            "output_field": "content_embedding"
        },
        {
            "input_field": "title",
            "output_field": "title_embedding"
        }
    ]
  }
}
--------------------------------------------------
// NOTCONSOLE

Selecting the input fields with `input_output` is incompatible with
the `target_field` and `field_map` options.

{dfanalytics-cap} models must use the `target_field` to specify the root 
location results are written to and optionally a `field_map` to map field names 
in the input document to the model input fields.

[source,js]
--------------------------------------------------
{
  "inference": {
    "model_id": "model_deployment_for_inference",
    "target_field": "FlightDelayMin_prediction_infer",
    "field_map": {
      "your_field": "my_field"
    },
    "inference_config": { "regression": {} }
  }
}
--------------------------------------------------
// NOTCONSOLE


[discrete]
[[inference-processor-classification-opt]]
==== {classification-cap} configuration options

Classification configuration for inference.

`num_top_classes`::
(Optional, integer)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-classification-num-top-classes]

`num_top_feature_importance_values`::
(Optional, integer)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-classification-num-top-feature-importance-values]

`results_field`::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field-processor]

`top_classes_results_field`::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-classification-top-classes-results-field]

`prediction_field_type`::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-classification-prediction-field-type]

[discrete]
[[inference-processor-fill-mask-opt]]
==== Fill mask configuration options

`num_top_classes`::
(Optional, integer)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-classification-num-top-classes]

`results_field`::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field-processor]

`tokenization`::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization]
+
.Properties of tokenization
[%collapsible%open]
=====
`bert`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-bert]
+
.Properties of bert
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`roberta`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-roberta]
+
.Properties of roberta
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`mpnet`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-mpnet]
+
.Properties of mpnet
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======
=====

[discrete]
[[inference-processor-ner-opt]]
==== NER configuration options

`results_field`::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field-processor]

`tokenization`::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization]
+
.Properties of tokenization
[%collapsible%open]
=====
`bert`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-bert]
+
.Properties of bert
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`roberta`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-roberta]
+
.Properties of roberta
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`mpnet`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-mpnet]
+
.Properties of mpnet
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======
=====

[discrete]
[[inference-processor-regression-opt]]
==== {regression-cap} configuration options

Regression configuration for inference.

`results_field`::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field-processor]

`num_top_feature_importance_values`::
(Optional, integer)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-regression-num-top-feature-importance-values]

[discrete]
[[inference-processor-text-classification-opt]]
==== Text classification configuration options

`classification_labels`::
(Optional, string) An array of classification labels.

`num_top_classes`::
(Optional, integer)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-classification-num-top-classes]

`results_field`::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field-processor]

`tokenization`::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization]
+
.Properties of tokenization
[%collapsible%open]
=====
`bert`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-bert]
+
.Properties of bert
[%collapsible%open]
=======

`span`::::
(Optional, integer)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-span]

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`roberta`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-roberta]
+
.Properties of roberta
[%collapsible%open]
=======

`span`::::
(Optional, integer)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-span]

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`mpnet`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-mpnet]
+
.Properties of mpnet
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======
=====

[discrete]
[[inference-processor-text-embedding-opt]]
==== Text embedding configuration options

`results_field`::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field-processor]

`tokenization`::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization]
+
.Properties of tokenization
[%collapsible%open]
=====
`bert`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-bert]
+
.Properties of bert
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`roberta`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-roberta]
+
.Properties of roberta
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`mpnet`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-mpnet]
+
.Properties of mpnet
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======
=====


[discrete]
[[inference-processor-text-expansion-opt]]
==== Text expansion configuration options

`results_field`::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field-processor]


`tokenization`::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization]
+
.Properties of tokenization
[%collapsible%open]
=====
`bert`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-bert]
+
.Properties of bert
[%collapsible%open]
=======

`span`::::
(Optional, integer)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-span]

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`roberta`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-roberta]
+
.Properties of roberta
[%collapsible%open]
=======

`span`::::
(Optional, integer)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-span]

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`mpnet`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-mpnet]
+
.Properties of mpnet
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======
=====

[discrete]
[[inference-processor-text-similarity-opt]]
==== Text similarity configuration options

`text_similarity`:::
(Object, optional)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-text-similarity]
+
.Properties of text_similarity inference
[%collapsible%open]
=====
`span_score_combination_function`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-text-similarity-span-score-func]

`tokenization`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization]
+
Refer to <<tokenization-properties>> to review the properties of the
`tokenization` object.
=====


[discrete]
[[inference-processor-zero-shot-opt]]
==== Zero shot classification configuration options

`labels`::
(Optional, array)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-zero-shot-classification-labels]

`multi_label`::
(Optional, boolean)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-zero-shot-classification-multi-label]

`results_field`::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-results-field-processor]

`tokenization`::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization]
+
.Properties of tokenization
[%collapsible%open]
=====
`bert`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-bert]
+
.Properties of bert
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`roberta`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-roberta]
+
.Properties of roberta
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======

`mpnet`::::
(Optional, object)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-mpnet]
+
.Properties of mpnet
[%collapsible%open]
=======

`truncate`::::
(Optional, string)
include::{es-ref-dir}/ml/ml-shared.asciidoc[tag=inference-config-nlp-tokenization-truncate]
=======
=====

[discrete]
[[inference-processor-config-example]]
==== {infer-cap} processor examples

[source,js]
--------------------------------------------------
"inference":{
  "model_id": "my_model_id",
  "field_map": {
    "original_fieldname": "expected_fieldname"
  },
  "inference_config": {
    "regression": {
      "results_field": "my_regression"
    }
  }
}
--------------------------------------------------
// NOTCONSOLE

This configuration specifies a `regression` inference and the results are
written to the `my_regression` field contained in the `target_field` results
object. The `field_map` configuration maps the field `original_fieldname` from
the source document to the field expected by the model.


[source,js]
--------------------------------------------------
"inference":{
  "model_id":"my_model_id"
  "inference_config": {
    "classification": {
      "num_top_classes": 2,
      "results_field": "prediction",
      "top_classes_results_field": "probabilities"
    }
  }
}
--------------------------------------------------
// NOTCONSOLE

This configuration specifies a `classification` inference. The number of
categories for which the predicted probabilities are reported is 2
(`num_top_classes`). The result is written to the `prediction` field and the top
classes to the `probabilities` field. Both fields are contained in the
`target_field` results object.

For an example that uses {nlp} trained models, refer to
{ml-docs}/ml-nlp-inference.html[Add NLP inference to ingest pipelines].

[discrete]
[[inference-processor-feature-importance]]
==== {feat-imp-cap} object mapping

To get the full benefit of aggregating and searching for
{ml-docs}/ml-feature-importance.html[{feat-imp}], update your index mapping of
the {feat-imp} result field as you can see below:

[source,js]
--------------------------------------------------
"ml.inference.feature_importance": {
  "type": "nested",
  "dynamic": true,
  "properties": {
    "feature_name": {
      "type": "keyword"
    },
    "importance": {
      "type": "double"
    }
  }
}
--------------------------------------------------
// NOTCONSOLE

The mapping field name for {feat-imp} (in the example above, it is
`ml.inference.feature_importance`) is compounded as follows:

`<ml.inference.target_field>`.`<inference.tag>`.`feature_importance`

* `<ml.inference.target_field>`: defaults to `ml.inference`.
* `<inference.tag>`: if is not provided in the processor definition, then it is
not part of the field path.

For example, if you provide a tag `foo` in the definition as you can see below:

[source,js]
--------------------------------------------------
{
  "tag": "foo",
  ...
}
--------------------------------------------------
// NOTCONSOLE


Then, the {feat-imp} value is written to the
`ml.inference.foo.feature_importance` field.

You can also specify the target field as follows:

[source,js]
--------------------------------------------------
{
  "tag": "foo",
  "target_field": "my_field"
}
--------------------------------------------------
// NOTCONSOLE

In this case, {feat-imp} is exposed in the
`my_field.foo.feature_importance` field.