Common optionsedit

The following options can be applied to all of the REST APIs.

Pretty Resultsedit

When appending ?pretty=true to any request made, the JSON returned will be pretty formatted (use it for debugging only!). Another option is to set ?format=yaml which will cause the result to be returned in the (sometimes) more readable yaml format.

Human readable outputedit

Statistics are returned in a format suitable for humans (eg "exists_time": "1h" or "size": "1kb") and for computers (eg "exists_time_in_millis": 3600000 or "size_in_bytes": 1024). The human readable values can be turned off by adding ?human=false to the query string. This makes sense when the stats results are being consumed by a monitoring tool, rather than intended for human consumption. The default for the human flag is false.

Date Mathedit

Most parameters which accept a formatted date value — such as gt and lt in range queries range queries, or from and to in daterange aggregations — understand date maths.

The expression starts with an anchor date, which can either be now, or a date string ending with ||. This anchor date can optionally be followed by one or more maths expressions:

  • +1h - add one hour
  • -1d - subtract one day
  • /d - round down to the nearest day

The supported time units are: y (year), M (month), w (week), d (day), h (hour), m (minute), and s (second).

Some examples are:

now+1h

The current time plus one hour, with ms resolution.

now+1h+1m

The current time plus one hour plus one minute, with ms resolution.

now+1h/d

The current time plus one hour, rounded down to the nearest day.

2015-01-01||+1M/d

2015-01-01 plus one month, rounded down to the nearest day.

Response Filteringedit

All REST APIs accept a filter_path parameter that can be used to reduce the response returned by elasticsearch. This parameter takes a comma separated list of filters expressed with the dot notation:

curl -XGET 'localhost:9200/_search?pretty&filter_path=took,hits.hits._id,hits.hits._score'
{
  "took" : 3,
  "hits" : {
    "hits" : [
      {
        "_id" : "3640",
        "_score" : 1.0
      },
      {
        "_id" : "3642",
        "_score" : 1.0
      }
    ]
  }
}

It also supports the * wildcard character to match any field or part of a field’s name:

curl -XGET 'localhost:9200/_nodes/stats?filter_path=nodes.*.ho*'
{
  "nodes" : {
    "lvJHed8uQQu4brS-SXKsNA" : {
      "host" : "portable"
    }
  }
}

And the ** wildcard can be used to include fields without knowing the exact path of the field. For example, we can return the Lucene version of every segment with this request:

curl 'localhost:9200/_segments?pretty&filter_path=indices.**.version'
{
  "indices" : {
    "movies" : {
      "shards" : {
        "0" : [ {
          "segments" : {
            "_0" : {
              "version" : "5.2.0"
            }
          }
        } ],
        "2" : [ {
          "segments" : {
            "_0" : {
              "version" : "5.2.0"
            }
          }
        } ]
      }
    },
    "books" : {
      "shards" : {
        "0" : [ {
          "segments" : {
            "_0" : {
              "version" : "5.2.0"
            }
          }
        } ]
      }
    }
  }
}

Note that elasticsearch sometimes returns directly the raw value of a field, like the _source field. If you want to filter _source fields, you should consider combining the already existing _source parameter (see Get API for more details) with the filter_path parameter like this:

curl -XGET 'localhost:9200/_search?pretty&filter_path=hits.hits._source&_source=title'
{
  "hits" : {
    "hits" : [ {
      "_source":{"title":"Book #2"}
    }, {
      "_source":{"title":"Book #1"}
    }, {
      "_source":{"title":"Book #3"}
    } ]
  }
}

Flat Settingsedit

The flat_settings flag affects rendering of the lists of settings. When flat_settings flag is true settings are returned in a flat format:

{
  "persistent" : { },
  "transient" : {
    "discovery.zen.minimum_master_nodes" : "1"
  }
}

When the flat_settings flag is false settings are returned in a more human readable structured format:

{
  "persistent" : { },
  "transient" : {
    "discovery" : {
      "zen" : {
        "minimum_master_nodes" : "1"
      }
    }
  }
}

By default the flat_settings is set to false.

Parametersedit

Rest parameters (when using HTTP, map to HTTP URL parameters) follow the convention of using underscore casing.

Boolean Valuesedit

All REST APIs parameters (both request parameters and JSON body) support providing boolean "false" as the values: false, 0, no and off. All other values are considered "true". Note, this is not related to fields within a document indexed treated as boolean fields.

Number Valuesedit

All REST APIs support providing numbered parameters as string on top of supporting the native JSON number types.

Time unitsedit

Whenever durations need to be specified, eg for a timeout parameter, the duration must specify the unit, like 2d for 2 days. The supported units are:

y

Year

M

Month

w

Week

d

Day

h

Hour

m

Minute

s

Second

ms

Milli-second

Data size unitsedit

Whenever the size of data needs to be specified, eg when setting a buffer size parameter, the value must specify the unit, like 10kb for 10 kilobytes. The supported units are:

b

Bytes

kb

Kilobytes

mb

Megabytes

gb

Gigabytes

tb

Terabytes

pb

Petabytes

Distance Unitsedit

Wherever distances need to be specified, such as the distance parameter in the Geo Distance Query), the default unit if none is specified is the meter. Distances can be specified in other units, such as "1km" or "2mi" (2 miles).

The full list of units is listed below:

Mile

mi or miles

Yard

yd or yards

Feet

ft or feet

Inch

in or inch

Kilometer

km or kilometers

Meter

m or meters

Centimeter

cm or centimeters

Millimeter

mm or millimeters

Nautical mile

NM, nmi or nauticalmiles

The precision parameter in the Geohash Cell Query accepts distances with the above units, but if no unit is specified, then the precision is interpreted as the length of the geohash.

Fuzzinessedit

Some queries and APIs support parameters to allow inexact fuzzy matching, using the fuzziness parameter. The fuzziness parameter is context sensitive which means that it depends on the type of the field being queried:

Numeric, date and IPv4 fieldsedit

When querying numeric, date and IPv4 fields, fuzziness is interpreted as a +/- margin. It behaves like a Range Query where:

-fuzziness <= field value <= +fuzziness

The fuzziness parameter should be set to a numeric value, eg 2 or 2.0. A date field interprets a long as milliseconds, but also accepts a string containing a time value — "1h" — as explained in Time unitsedit. An ip field accepts a long or another IPv4 address (which will be converted into a long).

String fieldsedit

When querying string fields, fuzziness is interpreted as a Levenshtein Edit Distance — the number of one character changes that need to be made to one string to make it the same as another string.

The fuzziness parameter can be specified as:

0, 1, 2
the maximum allowed Levenshtein Edit Distance (or number of edits)
AUTO

generates an edit distance based on the length of the term. For lengths:

0..2
must match exactly
3..5
one edit allowed
>5
two edits allowed

AUTO should generally be the preferred value for fuzziness.

Result Casingedit

All REST APIs accept the case parameter. When set to camelCase, all field names in the result will be returned in camel casing, otherwise, underscore casing will be used. Note, this does not apply to the source document indexed.

Request body in query stringedit

For libraries that don’t accept a request body for non-POST requests, you can pass the request body as the source query string parameter instead.