[[java-rest-high-document-delete-by-query]] === Delete By Query API [[java-rest-high-document-delete-by-query-request]] ==== Delete By Query Request A `DeleteByQueryRequest` can be used to delete documents from an index. It requires an existing index (or a set of indices) on which deletion is to be performed. The simplest form of a `DeleteByQueryRequest` looks like: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-request] -------------------------------------------------- <1> Creates the `DeleteByQueryRequest` on a set of indices. By default version conflicts abort the `DeleteByQueryRequest` process but you can just count them by settings it to `proceed` in the request body ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-request-conflicts] -------------------------------------------------- <1> Set `proceed` on version conflict You can limit the documents by adding a query. ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-request-query] -------------------------------------------------- <1> Only copy documents which have field `user` set to `kimchy` It’s also possible to limit the number of processed documents by setting size. ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-request-size] -------------------------------------------------- <1> Only copy 10 documents By default `DeleteByQueryRequest` uses batches of 1000. You can change the batch size with `setBatchSize`. ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-request-scrollSize] -------------------------------------------------- <1> Use batches of 100 documents `DeleteByQueryRequest` also helps in automatically parallelizing using `sliced-scroll` to slice on `_uid`. Use `setSlices` to specify the number of slices to use. ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-request-slices] -------------------------------------------------- <1> set number of slices to use `DeleteByQueryRequest` uses the `scroll` parameter to control how long it keeps the "search context" alive. ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-request-scroll] -------------------------------------------------- <1> set scroll time If you provide routing then the routing is copied to the scroll query, limiting the process to the shards that match that routing value. ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-request-routing] -------------------------------------------------- <1> set routing ==== Optional arguments In addition to the options above the following arguments can optionally be also provided: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-request-timeout] -------------------------------------------------- <1> Timeout to wait for the delete by query request to be performed as a `TimeValue` ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-request-refresh] -------------------------------------------------- <1> Refresh index after calling delete by query ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-request-indicesOptions] -------------------------------------------------- <1> Set indices options [[java-rest-high-document-delete-by-query-sync]] ==== Synchronous Execution ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-execute] -------------------------------------------------- [[java-rest-high-document-delete-by-query-async]] ==== Asynchronous Execution The asynchronous execution of an delete by query request requires both the `DeleteByQueryRequest` instance and an `ActionListener` instance to be passed to the asynchronous method: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-execute-async] -------------------------------------------------- <1> The `DeleteByQueryRequest` to execute and the `ActionListener` to use when the execution completes The asynchronous method does not block and returns immediately. Once it is completed the `ActionListener` is called back using the `onResponse` method if the execution successfully completed or using the `onFailure` method if it failed. A typical listener for `BulkByScrollResponse` looks like: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-execute-listener] -------------------------------------------------- <1> Called when the execution is successfully completed. The response is provided as an argument and contains a list of individual results for each operation that was executed. Note that one or more operations might have failed while the others have been successfully executed. <2> Called when the whole `DeleteByQueryRequest` fails. In this case the raised exception is provided as an argument and no operation has been executed. [[java-rest-high-document-delete-by-query-execute-listener-response]] ==== Delete By Query Response The returned `BulkByScrollResponse` contains information about the executed operations and allows to iterate over each result as follows: ["source","java",subs="attributes,callouts,macros"] -------------------------------------------------- include-tagged::{doc-tests}/CRUDDocumentationIT.java[delete-by-query-response] -------------------------------------------------- <1> Get total time taken <2> Check if the request timed out <3> Get total number of docs processed <4> Number of docs that were deleted <5> Number of batches that were executed <6> Number of skipped docs <7> Number of version conflicts <8> Number of times request had to retry bulk index operations <9> Number of times request had to retry search operations <10> The total time this request has throttled itself not including the current throttle time if it is currently sleeping <11> Remaining delay of any current throttle sleep or 0 if not sleeping <12> Failures during search phase <13> Failures during bulk index operation