Delete documents

POST /{index}/_delete_by_query

Deletes documents that match the specified query.

If the Elasticsearch security features are enabled, you must have the following index privileges for the target data stream, index, or alias:

read
delete or write

You can specify the query criteria in the request URI or the request body using the same syntax as the search API. When you submit a delete by query request, Elasticsearch gets a snapshot of the data stream or index when it begins processing the request and deletes matching documents using internal versioning. If a document changes between the time that the snapshot is taken and the delete operation is processed, it results in a version conflict and the delete operation fails.

NOTE: Documents with a version equal to 0 cannot be deleted using delete by query because internal versioning does not support 0 as a valid version number.

While processing a delete by query request, Elasticsearch performs multiple search requests sequentially to find all of the matching documents to delete. A bulk delete request is performed for each batch of matching documents. If a search or bulk request is rejected, the requests are retried up to 10 times, with exponential back off. If the maximum retry limit is reached, processing halts and all failed requests are returned in the response. Any delete requests that completed successfully still stick, they are not rolled back.

You can opt to count version conflicts instead of halting and returning by setting conflicts to proceed. Note that if you opt to count version conflicts the operation could attempt to delete more documents from the source than max_docs until it has successfully deleted max_docs documents, or it has gone through every document in the source query.

Throttling delete requests

To control the rate at which delete by query issues batches of delete operations, you can set requests_per_second to any positive decimal number. This pads each batch with a wait time to throttle the rate. Set requests_per_second to -1 to disable throttling.

Throttling uses a wait time between batches so that the internal scroll requests can be given a timeout that takes the request padding into account. The padding time is the difference between the batch size divided by the requests_per_second and the time spent writing. By default the batch size is 1000, so if requests_per_second is set to 500:

		target_time = 1000 / 500 per second = 2 seconds
wait_time = target_time - write_time = 2 seconds - .5 seconds = 1.5 seconds

Since the batch is issued as a single _bulk request, large batch sizes cause Elasticsearch to create many requests and wait before starting the next set. This is "bursty" instead of "smooth".

Slicing

Delete by query supports sliced scroll to parallelize the delete process. This can improve efficiency and provide a convenient way to break the request down into smaller parts.

Setting slices to auto lets Elasticsearch choose the number of slices to use. This setting will use one slice per shard, up to a certain limit. If there are multiple source data streams or indices, it will choose the number of slices based on the index or backing index with the smallest number of shards. Adding slices to the delete by query operation creates sub-requests which means it has some quirks:

You can see these requests in the tasks APIs. These sub-requests are "child" tasks of the task for the request with slices.
Fetching the status of the task for the request with slices only contains the status of completed slices.
These sub-requests are individually addressable for things like cancellation and rethrottling.
Rethrottling the request with slices will rethrottle the unfinished sub-request proportionally.
Canceling the request with slices will cancel each sub-request.
Due to the nature of slices each sub-request won't get a perfectly even portion of the documents. All documents will be addressed, but some slices may be larger than others. Expect larger slices to have a more even distribution.
Parameters like requests_per_second and max_docs on a request with slices are distributed proportionally to each sub-request. Combine that with the earlier point about distribution being uneven and you should conclude that using max_docs with slices might not result in exactly max_docs documents being deleted.
Each sub-request gets a slightly different snapshot of the source data stream or index though these are all taken at approximately the same time.

If you're slicing manually or otherwise tuning automatic slicing, keep in mind that:

Query performance is most efficient when the number of slices is equal to the number of shards in the index or backing index. If that number is large (for example, 500), choose a lower number as too many slices hurts performance. Setting slices higher than the number of shards generally does not improve efficiency and adds overhead.
Delete performance scales linearly across available resources with the number of slices.

Whether query or delete performance dominates the runtime depends on the documents being reindexed and cluster resources.

Cancel a delete by query operation

Any delete by query can be canceled using the task cancel API. For example:

POST _tasks/r1A2WoRbTwKZ516z6NEs5A:36619/_cancel

The task ID can be found by using the get tasks API.

Cancellation should happen quickly but might take a few seconds. The get task status API will continue to list the delete by query task until this task checks that it has been cancelled and terminates itself.

Required authorization

Index privileges: read,delete

Path Parameters

index union IndexName | [] IndexName required: A comma-separated list of data streams, indices, and aliases to search. It supports wildcards (*). To search all data streams or indices, omit this parameter or use * or _all.

Query Parameters

allow_no_indices boolean · default: true

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.

analyzer string

Analyzer to use for the query string. This parameter can be used only when the q query string parameter is specified.

analyze_wildcard boolean · default: false

If true, wildcard and prefix queries are analyzed. This parameter can be used only when the q query string parameter is specified.

conflicts enum Conflicts · default: abort

What to do if delete by query hits version conflicts: abort or proceed.

Supported values include:

abort: Stop reindexing if there are conflicts.
proceed: Continue reindexing even if there are conflicts.

Values: abort proceed

default_operator enum Operator · default: or

The default operator for query string query: and or or. This parameter can be used only when the q query string parameter is specified.

Values: and AND or OR

df string

The field to use as default where no field prefix is given in the query string. This parameter can be used only when the q query string parameter is specified.

expand_wildcards string ExpandWildcards · default: open

The 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. It supports comma-separated values, such as open,hidden.

Supported values include:

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 expressions are not accepted.

Values: all open closed hidden none

from number · default: 0

Skips the specified number of documents.

ignore_unavailable boolean · default: false

If false, the request returns an error if it targets a missing or closed index.

lenient boolean · default: false

If true, format-based query failures (such as providing text to a numeric field) in the query string will be ignored. This parameter can be used only when the q query string parameter is specified.

max_docs number

The maximum number of documents to process. Defaults to all documents. When set to a value less then or equal to scroll_size, a scroll will not be used to retrieve the results for the operation.

preference string

The node or shard the operation should be performed on. It is random by default.

refresh boolean · default: false

If true, Elasticsearch refreshes all shards involved in the delete by query after the request completes. This is different than the delete API's refresh parameter, which causes just the shard that received the delete request to be refreshed. Unlike the delete API, it does not support wait_for.

request_cache boolean

If true, the request cache is used for this request. Defaults to the index-level setting.

requests_per_second number · default: -1

The throttle for this request in sub-requests per second.

routing string Routing

A custom value used to route operations to a specific shard.

q string

A query in the Lucene query string syntax.

scroll string Duration

The period to retain the search context for scrolling.

scroll_size number · default: 1000

The size of the scroll request that powers the operation.

search_timeout string Duration

The explicit timeout for each search request. It defaults to no timeout.

search_type enum SearchType

The type of the search operation. Available options include query_then_fetch and dfs_query_then_fetch.

Supported values include:

query_then_fetch: Documents are scored using local term and document frequencies for the shard. This is usually faster but less accurate.
dfs_query_then_fetch: Documents are scored using global term and document frequencies across all shards. This is usually slower but more accurate.

Values: query_then_fetch dfs_query_then_fetch

slices Slices · default: 1

The number of slices this task should be divided into.

Values: auto

sort [] string deprecated

A comma-separated list of <field>:<direction> pairs.

stats [] string

The specific tag of the request for logging and statistical purposes.

terminate_after number

The maximum number of documents to collect for each shard. If a query reaches this limit, Elasticsearch terminates the query early. Elasticsearch collects documents before sorting.

Use with caution. Elasticsearch applies this parameter to each shard handling the request. When possible, let Elasticsearch perform early termination automatically. Avoid specifying this parameter for requests that target data streams with backing indices across multiple data tiers.

timeout string Duration · default: 1m

The period each deletion request waits for active shards.

version boolean

If true, returns the document version as part of a hit.

wait_for_active_shards WaitForActiveShards · default: 1

The number of shard copies that must be active before proceeding with the operation. Set to all or any positive integer up to the total number of shards in the index (number_of_replicas+1). The timeout value controls how long each write request waits for unavailable shards to become available.

Values: all index-setting

wait_for_completion boolean · default: true

If true, the request blocks until the operation is complete. If false, Elasticsearch performs some preflight checks, launches the request, and returns a task you can use to cancel or get the status of the task. Elasticsearch creates a record of this task as a document at .tasks/task/${taskId}. When you are done with a task, you should delete the task document so Elasticsearch can reclaim the space.

Request

Response

application/json

batches number: The number of scroll responses pulled back by the delete by query.
deleted number: The number of documents that were successfully deleted.
failures [] BulkIndexByScrollFailure: An array of failures if there were any unrecoverable errors during the process. If this array is not empty, the request ended abnormally because of those failures. Delete by query is implemented using batches and any failures cause the entire process to end but all failures in the current batch are collected into the array. You can use the conflicts option to prevent reindex from ending on version conflicts.
noops number: This field is always equal to zero for delete by query. It exists only so that delete by query, update by query, and reindex APIs return responses with the same structure.
requests_per_second number: The number of requests per second effectively run during the delete by query.
retries {} Retries: The number of retries attempted by delete by query. bulk is the number of bulk actions retried. search is the number of search actions retried.
slice_id number
task number | string TaskId
throttled string Duration
throttled_millis DurationValueUnitMillis: The number of milliseconds the request slept to conform to requests_per_second.
throttled_until string Duration
throttled_until_millis DurationValueUnitMillis: This field should always be equal to zero in a _delete_by_query response. It has meaning only when using the task API, where it indicates the next time (in milliseconds since epoch) a throttled request will be run again in order to conform to requests_per_second.
timed_out boolean: If true, some requests run during the delete by query operation timed out.
took DurationValueUnitMillis: The number of milliseconds from start to end of the whole operation.
total number: The number of documents that were successfully processed.
version_conflicts number: The number of version conflicts that the delete by query hit.

Examples

Run POST /my-index-000001,my-index-000002/_delete_by_query to delete all documents from multiple data streams or indices.

Request Console 1 / 8 languages

Console Kibana Dev Tools

POST /my-index-000001,my-index-000002/_delete_by_query
{
  "query": {
    "match_all": {}
  }
}

JavaScript Elasticsearch JavaScript Client

const response = await client.deleteByQuery({
  index: "my-index-000001,my-index-000002",
  query: {
    match_all: {},
  },
});

Python Elasticsearch Python Client

resp = client.delete_by_query(
    index="my-index-000001,my-index-000002",
    query={
        "match_all": {}
    },
)

curl Shell

curl -X POST "$ELASTICSEARCH_URL/my-index-000001,my-index-000002/_delete_by_query" \
  -H "Authorization: ApiKey $ELASTIC_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "query": {
      "match_all": {}
    }
  }'

Java Elasticsearch Java Client

client.deleteByQuery(d -> d
    .index(List.of("my-index-000001","my-index-000002"))
    .query(q -> q
        .matchAll(m -> m)
    )
);

C# Elasticsearch .NET Client

var response = await client
    .DeleteByQueryAsync(indices: new[] { "my-index-000001", "my-index-000002" }, d1 => d1
        .Query(d2 => d2
            .MatchAll()
        )
    );

PHP Elasticsearch PHP Client

$resp = $client->deleteByQuery([
    "index" => "my-index-000001,my-index-000002",
    "body" => [
        "query" => [
            "match_all" => new ArrayObject([]),
        ],
    ],
]);

Ruby Elasticsearch Ruby Client

response = client.delete_by_query(
  index: "my-index-000001,my-index-000002",
  body: {
    "query": {
      "match_all": {}
    }
  }
)

Response

{
  "took" : 147,
  "timed_out": false,
  "total": 119,
  "deleted": 119,
  "batches": 1,
  "version_conflicts": 0,
  "noops": 0,
  "retries": {
    "bulk": 0,
    "search": 0
  },
  "throttled_millis": 0,
  "requests_per_second": -1.0,
  "throttled_until_millis": 0,
  "failures" : [ ]
}

Run POST my-index-000001/_delete_by_query to delete a document by using a unique attribute.

Request Console 1 / 2 languages

Console Kibana Dev Tools

POST my-index-000001/_delete_by_query
{
  "query": {
    "term": {
      "user.id": "kimchy"
    }
  },
  "max_docs": 1
}

curl Shell

curl -X POST "$ELASTICSEARCH_URL/my-index-000001/_delete_by_query" \
  -H "Authorization: ApiKey $ELASTIC_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "query": {
    "term": {
      "user.id": "kimchy"
    }
  },
  "max_docs": 1
}'

Response

{
  "took" : 147,
  "timed_out": false,
  "total": 119,
  "deleted": 119,
  "batches": 1,
  "version_conflicts": 0,
  "noops": 0,
  "retries": {
    "bulk": 0,
    "search": 0
  },
  "throttled_millis": 0,
  "requests_per_second": -1.0,
  "throttled_until_millis": 0,
  "failures" : [ ]
}

Run POST my-index-000001/_delete_by_query to slice a delete by query manually. Provide a slice ID and total number of slices.

Request Console 1 / 2 languages

Console Kibana Dev Tools

POST my-index-000001/_delete_by_query
{
  "slice": {
    "id": 0,
    "max": 2
  },
  "query": {
    "range": {
      "http.response.bytes": {
        "lt": 2000000
      }
    }
  }
}

curl Shell

curl -X POST "$ELASTICSEARCH_URL/my-index-000001/_delete_by_query" \
  -H "Authorization: ApiKey $ELASTIC_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "slice": {
    "id": 0,
    "max": 2
  },
  "query": {
    "range": {
      "http.response.bytes": {
        "lt": 2000000
      }
    }
  }
}'

Response

{
  "took" : 147,
  "timed_out": false,
  "total": 119,
  "deleted": 119,
  "batches": 1,
  "version_conflicts": 0,
  "noops": 0,
  "retries": {
    "bulk": 0,
    "search": 0
  },
  "throttled_millis": 0,
  "requests_per_second": -1.0,
  "throttled_until_millis": 0,
  "failures" : [ ]
}

Run POST my-index-000001/_delete_by_query?refresh&slices=5 to let delete by query automatically parallelize using sliced scroll to slice on _id. The slices query parameter value specifies the number of slices to use.

Request Console 1 / 2 languages

Console Kibana Dev Tools

POST my-index-000001/_delete_by_query?refresh&slices=5
{
  "query": {
    "range": {
      "http.response.bytes": {
        "lt": 2000000
      }
    }
  }
}

curl Shell

curl -X POST "$ELASTICSEARCH_URL/my-index-000001/_delete_by_query?refresh&slices=5" \
  -H "Authorization: ApiKey $ELASTIC_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "query": {
    "range": {
      "http.response.bytes": {
        "lt": 2000000
      }
    }
  }
}'

Response

{
  "took" : 147,
  "timed_out": false,
  "total": 119,
  "deleted": 119,
  "batches": 1,
  "version_conflicts": 0,
  "noops": 0,
  "retries": {
    "bulk": 0,
    "search": 0
  },
  "throttled_millis": 0,
  "requests_per_second": -1.0,
  "throttled_until_millis": 0,
  "failures" : [ ]
}

Required authorization

Path Parameters

Request { max_docs , query , slice , sort , }

Response

Request