elasticsearch/docs/java-rest/high-level/document/reindex-rethrottle.asciidoc

[[java-rest-high-document-reindex-rethrottle]]
=== Reindex Rethrottle API

[[java-rest-high-document-reindex-rethrottle-request]]
==== Reindex Rethrolle Request

A `RethrottleRequest` can be used to change existing throttling on a runnind
reindex task or disable it entirely. It requires the task Id of the reindex 
task to change.

In its simplest form, you can use it to disable throttling of a running
reindex task using the following:

["source","java",subs="attributes,callouts,macros"]
--------------------------------------------------
include-tagged::{doc-tests}/CRUDDocumentationIT.java[rethrottle-disable-request]
--------------------------------------------------
<1> Create a `RethrottleRequest` that disables throttling for a specific task id

By providing a `requestsPerSecond` argument, the request will change the
existing task throttling to the specified value:

["source","java",subs="attributes,callouts,macros"]
--------------------------------------------------
include-tagged::{doc-tests}/CRUDDocumentationIT.java[rethrottle-request]
--------------------------------------------------
<1> Request to change the throttling of a task to 100 requests per second

[[java-rest-high-document-reindex-rethrottle-async]]
==== Asynchronous Execution

The asynchronous execution of a rethrottle request requires both the `RethrottleRequest`
instance and an `ActionListener` instance to be passed to the asynchronous
method:

["source","java",subs="attributes,callouts,macros"]
--------------------------------------------------
include-tagged::{doc-tests}/CRUDDocumentationIT.java[rethrottle-execute-async]
--------------------------------------------------
<1> The RethrottleRequest 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 looks like this:

["source","java",subs="attributes,callouts,macros"]
--------------------------------------------------
include-tagged::{doc-tests}/CRUDDocumentationIT.java[rethrottle-request-async]
--------------------------------------------------
<1> Code executed when the request is successfully completed
<2> Code executed when the request fails with an exception

[[java-rest-high-document-reindex-retrottle-response]]
==== Rethrottle Response

Rethrottling returns the task that has been rethrottled in the form of a 
`ListTasksResponse`. The structure of this response object is described in detail 
in <<java-rest-high-cluster-list-tasks-response,this section>>.