Set processor
The set
processor adds or updates fields in a document. It sets one field and associates it with the specified value. If the field already exists, then its value is replaced with the provided one unless the override
parameter is set to false
. When override
is false
and the specified field exists, the value of the field remains unchanged.
The following is the syntax for the set
processor:
{
"description": "...",
"processors": [
{
"set": {
"field": "new_field",
"value": "some_value"
}
}
]
}
Configuration parameters
The following table lists the required and optional parameters for the set
processor.
Parameter | Required/Optional | Description |
---|---|---|
field | Required | The name of the field to be set or updated. Supports template snippets. |
value | Required | The value assigned to the field. Supports template snippets. |
override | Optional | A Boolean flag that determines whether the processor should override the existing value of the field. |
ignore_empty_value | Optional | A Boolean flag that determines whether the processor should ignore null values or empty strings. Default is false . |
description | Optional | A description of the processor’s purpose or configuration. |
if | Optional | Specifies to conditionally execute the processor. |
ignore_failure | Optional | Specifies to ignore processor failures. See Handling pipeline failures. |
on_failure | Optional | Specifies a list of processors to run if the processor fails during execution. These processors are executed in the order they are specified. |
tag | Optional | An identifier tag for the processor. Useful for debugging in order to distinguish between processors of the same type. |
Using the processor
Follow these steps to use the processor in a pipeline.
Step 1: Create a pipeline
The following query creates a pipeline named set-pipeline
that uses the set
processor to add a new field new_field
with the value some_value
to the document:
PUT _ingest/pipeline/set-pipeline
{
"description": "Adds a new field 'new_field' with the value 'some_value'",
"processors": [
{
"set": {
"field": "new_field",
"value": "some_value"
}
}
]
}
Step 2 (Optional): Test the pipeline
It is recommended that you test your pipeline before you ingest documents.
To test the pipeline, run the following query:
POST _ingest/pipeline/set-pipeline/_simulate
{
"docs": [
{
"_source": {
"existing_field": "value"
}
}
]
}
Response
The following example response confirms that the pipeline is working as expected:
{
"docs": [
{
"doc": {
"_index": "_index",
"_id": "_id",
"_source": {
"existing_field": "value",
"new_field": "some_value"
},
"_ingest": {
"timestamp": "2024-05-30T21:56:15.066180712Z"
}
}
}
]
}
Step 3: Ingest a document
The following query ingests a document into an index named testindex1
:
POST testindex1/_doc?pipeline=set-pipeline
{
"existing_field": "value"
}
Response
The request indexes the document into the index testindex1
and then indexes all documents with the new_field
set to some_value
, as shown in the following response:
{
"_index": "testindex1",
"_id": "1",
"_version": 1,
"result": "created",
"_shards": {
"total": 2,
"successful": 1,
"failed": 0
},
"_seq_no": 0,
"_primary_term": 1
}
Step 4 (Optional): Retrieve the document
To retrieve the document, run the following query:
GET testindex1/_doc/1