Clear cache API

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Clears the caches of one or more indices. For data streams, the API clears the caches of the stream’s backing indices.

response = client.indices.clear_cache(
  index: 'my-index-000001'
)
puts response
POST /my-index-000001/_cache/clear

Request

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POST /<target>/_cache/clear

POST /_cache/clear

Prerequisites

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  • If the Elasticsearch security features are enabled, you must have the manage index privilege for the target data stream, index, or alias.

Path parameters

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<target>
(Optional, string) Comma-separated list of data streams, indices, and aliases used to limit the request. Supports wildcards (*). To target all data streams and indices, omit this parameter or use * or _all.

Query parameters

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allow_no_indices

(Optional, Boolean) If false, the request returns an error if any wildcard expression, index alias, or _all value targets only missing or closed indices. This behavior applies even if the request targets other open indices. For example, a request targeting foo*,bar* returns an error if an index starts with foo but no index starts with bar.

Defaults to true.

expand_wildcards

(Optional, string) Type of index that wildcard patterns can match. If the request can target data streams, this argument determines whether wildcard expressions match hidden data streams. Supports comma-separated values, such as open,hidden. Valid values are:

all
Match any data stream or index, including hidden ones.
open
Match open, non-hidden indices. Also matches any non-hidden data stream.
closed
Match closed, non-hidden indices. Also matches any non-hidden data stream. Data streams cannot be closed.
hidden
Match hidden data streams and hidden indices. Must be combined with open, closed, or both.
none
Wildcard patterns are not accepted.

Defaults to open.

fielddata

(Optional, Boolean) If true, clears the fields cache.

Use the fields parameter to clear the cache of specific fields only.

fields

(Optional, string) Comma-separated list of field names used to limit the fielddata parameter.

Defaults to all fields.

This parameter does not support objects or field aliases.

index
(Optional, string) Comma-separated list of index names used to limit the request.
ignore_unavailable
(Optional, Boolean) If false, the request returns an error if it targets a missing or closed index. Defaults to false.
query
(Optional, Boolean) If true, clears the query cache.
request
(Optional, Boolean) If true, clears the request cache.

Examples

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Clear a specific cache

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By default, the clear cache API clears all caches. You can clear only specific caches by setting the following query parameters to true:

  • fielddata
  • query
  • request
response = client.indices.clear_cache(
  index: 'my-index-000001',
  fielddata: true
)
puts response

response = client.indices.clear_cache(
  index: 'my-index-000001',
  query: true
)
puts response

response = client.indices.clear_cache(
  index: 'my-index-000001',
  request: true
)
puts response
POST /my-index-000001/_cache/clear?fielddata=true  
POST /my-index-000001/_cache/clear?query=true      
POST /my-index-000001/_cache/clear?request=true    

Clears only the fields cache

Clears only the query cache

Clears only the request cache

Clear the cache of specific fields

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To only clear the cache of specific fields, use the fields query parameter.

response = client.indices.clear_cache(
  index: 'my-index-000001',
  fields: 'foo,bar'
)
puts response
POST /my-index-000001/_cache/clear?fields=foo,bar   

Clear the cache for the foo and bar field

Clear caches for several data streams and indices

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POST /my-index-000001,my-index-000002/_cache/clear

Clear caches for all data streams and indices

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response = client.indices.clear_cache
puts response
POST /_cache/clear