elasticsearch/docs/reference/enrich-processor/date-index-name-processor.md

---

navigation_title: "Date index name" mapped_pages:

• https://www.elastic.co/guide/en/elasticsearch/reference/current/date-index-name-processor.html ---

Date index name processor [date-index-name-processor]

The purpose of this processor is to point documents to the right time based index based on a date or timestamp field in a document by using the date math index name support.

The processor sets the _index metadata field with a date math index name expression based on the provided index name prefix, a date or timestamp field in the documents being processed and the provided date rounding.

First, this processor fetches the date or timestamp from a field in the document being processed. Optionally, date formatting can be configured on how the field’s value should be parsed into a date. Then this date, the provided index name prefix and the provided date rounding get formatted into a date math index name expression. Also here optionally date formatting can be specified on how the date should be formatted into a date math index name expression.

An example pipeline that points documents to a monthly index that starts with a my-index- prefix based on a date in the date1 field:

PUT _ingest/pipeline/monthlyindex
{
  "description": "monthly date-time index naming",
  "processors" : [
    {
      "date_index_name" : {
        "field" : "date1",
        "index_name_prefix" : "my-index-",
        "date_rounding" : "M"
      }
    }
  ]
}

Using that pipeline for an index request:

PUT /my-index/_doc/1?pipeline=monthlyindex
{
  "date1" : "2016-04-25T12:02:01.789Z"
}

{
  "_index" : "my-index-2016-04-01",
  "_id" : "1",
  "_version" : 1,
  "result" : "created",
  "_shards" : {
    "total" : 2,
    "successful" : 1,
    "failed" : 0
  },
  "_seq_no" : 55,
  "_primary_term" : 1
}

The above request will not index this document into the my-index index, but into the my-index-2016-04-01 index because it was rounded by month. This is because the date-index-name-processor overrides the _index property of the document.

To see the date-math value of the index supplied in the actual index request which resulted in the above document being indexed into my-index-2016-04-01 we can inspect the effects of the processor using a simulate request.

POST _ingest/pipeline/_simulate
{
  "pipeline" :
  {
    "description": "monthly date-time index naming",
    "processors" : [
      {
        "date_index_name" : {
          "field" : "date1",
          "index_name_prefix" : "my-index-",
          "date_rounding" : "M"
        }
      }
    ]
  },
  "docs": [
    {
      "_source": {
        "date1": "2016-04-25T12:02:01.789Z"
      }
    }
  ]
}

and the result:

{
  "docs" : [
    {
      "doc" : {
        "_id" : "_id",
        "_index" : "<my-index-{2016-04-25||/M{yyyy-MM-dd|UTC}}>",
        "_version" : "-3",
        "_source" : {
          "date1" : "2016-04-25T12:02:01.789Z"
        },
        "_ingest" : {
          "timestamp" : "2016-11-08T19:43:03.850+0000"
        }
      }
    }
  ]
}

The above example shows that _index was set to <my-index-{2016-04-25||/M{yyyy-MM-dd|UTC}}>. Elasticsearch understands this to mean 2016-04-01 as is explained in the date math index name documentation

$$$date-index-name-options$$$

Name	Required	Default	Description
field	yes	-	The field to get the date or timestamp from.
index_name_prefix	no	-	A prefix of the index name to be prepended before the printed date. Supports template snippets.
date_rounding	yes	-	How to round the date when formatting the date into the index name. Valid values are: y (year), M (month), w (week), d (day), h (hour), m (minute) and s (second). Supports template snippets.
date_formats	no	yyyy-MM-dd'T'HH:mm:ss.SSSXX	An array of the expected date formats for parsing dates / timestamps in the document being preprocessed. Can be a java time pattern or one of the following formats: ISO8601, UNIX, UNIX_MS, or TAI64N.
timezone	no	UTC	The timezone to use when parsing the date and when date math index supports resolves expressions into concrete index names.
locale	no	ENGLISH	The locale to use when parsing the date from the document being preprocessed, relevant when parsing month names or week days.
index_name_format	no	yyyy-MM-dd	The format to be used when printing the parsed date into the index name. A valid java time pattern is expected here. Supports template snippets.
description	no	-	Description of the processor. Useful for describing the purpose of the processor or its configuration.
if	no	-	Conditionally execute the processor. See Conditionally run a processor.
ignore_failure	no	false	Ignore failures for the processor. See Handling pipeline failures.
on_failure	no	-	Handle failures for the processor. See Handling pipeline failures.
tag	no	-	Identifier for the processor. Useful for debugging and metrics.