Update documents

Auth

Updates documents that match the specified query. If no query is specified, performs an update on every document in the data stream or index without modifying the source, which is useful for picking up mapping changes.

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

  • read
  • index 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 an update by query request, Elasticsearch gets a snapshot of the data stream or index when it begins processing the request and updates matching documents using internal versioning. When the versions match, the document is updated and the version number is incremented. If a document changes between the time that the snapshot is taken and the update operation is processed, it results in a version conflict and the operation fails. 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 update more documents from the source than max_docs until it has successfully updated max_docs documents or it has gone through every document in the source query.

Note

Documents with a version equal to 0 cannot be updated using update by query because internal versioning does not support 0 as a valid version number.

While processing an update by query request, Elasticsearch performs multiple search requests sequentially to find all of the matching documents. A bulk update request is performed for each batch of matching documents. Any query or update failures cause the update by query request to fail and the failures are shown in the response. Any update requests that completed successfully still stick, they are not rolled back.

Throttling update requests

To control the rate at which update by query issues batches of update 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 turn off 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

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

Setting slices to auto chooses a reasonable number for most data streams and indices. 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 _update_by_query just automates the manual process of creating 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 point above about distribution being uneven and you should conclude that using max_docs with slices might not result in exactly max_docs documents being updated.
  • 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.
  • Update performance scales linearly across available resources with the number of slices.

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

Update the document source

Update by query supports scripts to update the document source. As with the update API, you can set ctx.op to change the operation that is performed.

Set ctx.op = "noop" if your script decides that it doesn't have to make any changes. The update by query operation skips updating the document and increments the noop counter.

Set ctx.op = "delete" if your script decides that the document should be deleted. The update by query operation deletes the document and increments the deleted counter.

Update by query supports only index, noop, and delete. Setting ctx.op to anything else is an error. Setting any other field in ctx is an error. This API enables you to only modify the source of matching documents; you cannot move them.

Required authorization

Index privileges read write

Path parameters

index union string | string[] 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

The 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 · default: abort

The preferred behavior when update 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 · 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 union oneOf · 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. It defaults to all documents. When set to a value less then or equal to scroll_size then a scroll will not be used to retrieve the results for the operation.

pipeline string

The ID of the pipeline to use to preprocess incoming documents. If the index has a default ingest pipeline specified, then setting the value to _none disables the default ingest pipeline for this request. If a final pipeline is configured it will always run, regardless of the value of this parameter.

preference string

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

q string

A query in the Lucene query string syntax.

refresh boolean · default: false

If true, Elasticsearch refreshes affected shards to make the operation visible to search after the request completes. This is different than the update API's refresh parameter, which causes just the shard that received the request to be refreshed.

request_cache boolean

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

requests_per_second number · default: -1

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

routing string

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

scroll string · default: 5m

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

An explicit timeout for each search request. By default, there is no timeout.

Reference
search_type enum

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 union oneOf · default: 1

The number of slices this task should be divided into.

Values: auto
sort string[]

A comma-separated list of

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.

Important

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 · default: 1m

The period each update request waits for the following operations: dynamic mapping updates, waiting for active shards. By default, it is one minute. This guarantees Elasticsearch waits for at least the timeout before failing. The actual wait time could be longer, particularly when multiple waits occur.

version boolean

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

version_type boolean

Should the document increment the version number (internal) on hit or not (reindex)

wait_for_active_shards union oneOf · 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 parameter controls how long each write request waits for unavailable shards to become available. Both work exactly the way they work in the bulk API.

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 ID that 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}.

Request body

max_docs number

The maximum number of documents to update.

query {} Query

The documents to update using the Query DSL.

script string

The script to run to update the document source or metadata when updating.

slice object

Slice the request manually using the provided slice ID and total number of slices.

field string
id string required
max number required
conflicts enum · default: abort

The preferred behavior when update 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

Response

application/json
batches number

The number of scroll responses pulled back by the update by query.

failures object[]

Array of failures if there were any unrecoverable errors during the process. If this is non-empty then the request ended because of those failures. Update by query is implemented using batches. Any failure causes 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 when version conflicts occur.

cause object required
type string required

The type of error

reason union string nullable

A human-readable explanation of the error, in English.

One of: string
stack_trace string

The server stack trace. Present only if the error_trace=true parameter was sent with the request.

caused_by object
Same fields as cause in failures
root_cause object[]
Same fields as cause in failures
suppressed object[]
Same fields as cause in failures
id string required
index string required
status number required
noops number

The number of documents that were ignored because the script used for the update by query returned a noop value for ctx.op.

deleted number

The number of documents that were successfully deleted.

requests_per_second number

The number of requests per second effectively run during the update by query.

retries object

The number of retries attempted by update by query. bulk is the number of bulk actions retried. search is the number of search actions retried.

bulk number required

The number of bulk actions retried.

The number of search actions retried.

task number | string
timed_out boolean

If true, some requests timed out during the update by query.

took number

The number of milliseconds from start to end of the whole operation.

total number

The number of documents that were successfully processed.

updated number

The number of documents that were successfully updated.

version_conflicts number

The number of version conflicts that the update by query hit.

throttled string
throttled_millis number

The number of milliseconds the request slept to conform to requests_per_second.

throttled_until string
throttled_until_millis number

This field should always be equal to zero in an _update_by_query response. It only has meaning 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.