[[ingest]]
= Ingest node

[partintro]
--
Use an ingest node to pre-process documents before the actual document indexing happens.
The ingest node intercepts bulk and index requests, it applies transformations, and it then
passes the documents back to the index or bulk APIs.

All nodes enable ingest by default, so any node can handle ingest tasks. To
create a dedicated ingest node, configure the <<modules-node,`node.roles`>>
setting in `elasticsearch.yml` as follows:

[source,yaml]
----
node.roles: [ ingest ]
----

To disable ingest for a node, specify the `node.roles` setting and exclude
`ingest` from the listed roles.

To pre-process documents before indexing, <<pipeline,define a pipeline>> that specifies a series of
<<ingest-processors,processors>>. Each processor transforms the document in some specific way. For example, a
pipeline might have one processor that removes a field from the document, followed by
another processor that renames a field. The <<cluster-state,cluster state>> then stores
the configured pipelines.

To use a pipeline, simply specify the `pipeline` parameter on an index or bulk request. This
way, the ingest node knows which pipeline to use.

For example:
Create a pipeline

[source,console]
--------------------------------------------------
PUT _ingest/pipeline/my_pipeline_id
{
  "description" : "describe pipeline",
  "processors" : [
    {
      "set" : {
        "field": "foo",
        "value": "new"
      }
    }
  ]
}
--------------------------------------------------

Index with defined pipeline

[source,console]
--------------------------------------------------
PUT my-index-000001/_doc/my-id?pipeline=my_pipeline_id
{
  "foo": "bar"
}
--------------------------------------------------
// TEST[continued]

Response：

[source,console-result]
--------------------------------------------------
{
  "_index" : "my-index-000001",
  "_id" : "my-id",
  "_version" : 1,
  "result" : "created",
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "failed" : 0
  },
  "_seq_no" : 0,
  "_primary_term" : 1
}
--------------------------------------------------
// TESTRESPONSE[s/"successful" : 2/"successful" : 1/]

An index may also declare a <<dynamic-index-settings,default pipeline>> that will be used in the
absence of the `pipeline` parameter.

Finally, an index may also declare a <<dynamic-index-settings,final pipeline>>
that will be executed after any request or default pipeline (if any).

See <<ingest-apis,Ingest APIs>> for more information about creating, adding, and deleting pipelines.

--

include::ingest/ingest-node.asciidoc[]