--
:api: rollup-get-rollup-caps
:request: GetRollupCapsRequest
:response: GetRollupCapsResponse
--
[role="xpack"]
[id="{upid}-x-pack-{api}"]
=== Get Rollup Capabilities API

experimental::[]

The Get Rollup Capabilities API allows the user to query a target index pattern (`logstash-*`, etc)
and determine if there are any rollup jobs that are/were configured to rollup that pattern.
The API accepts a `GetRollupCapsRequest` object as a request and returns a `GetRollupCapsResponse`.

[id="{upid}-x-pack-{api}-request"]
==== Get Rollup Capabilities Request

A +{request}+ requires a single parameter: the target index or index pattern (e.g. `logstash-*`):

["source","java",subs="attributes,callouts,macros"]
--------------------------------------------------
include-tagged::{doc-tests-file}[x-pack-{api}-request]
--------------------------------------------------

[id="{upid}-x-pack-{api}-execution"]
==== Execution

The Get Rollup Capabilities API can be executed through a `RollupClient`
instance. Such instance can be retrieved from a `RestHighLevelClient`
using the `rollup()` method:

["source","java",subs="attributes,callouts,macros"]
--------------------------------------------------
include-tagged::{doc-tests-file}[x-pack-{api}-execute]
--------------------------------------------------

[id="{upid}-x-pack-{api}-response"]
==== Response

The returned +{response}+ holds lists and maps of values which correspond to the capabilities
of the target index/index pattern (what jobs were configured for the pattern, where the data is stored, what
aggregations are available, etc).  It provides essentially the same data as the original job configuration,
just presented in a different manner.

For example, if we had created a job with the following config:

["source","java",subs="attributes,callouts,macros"]
--------------------------------------------------
include-tagged::{doc-tests-file}[x-pack-{api}-setup]
--------------------------------------------------

The +{response}+ object would contain the same information, laid out in a slightly different manner:

["source","java",subs="attributes,callouts,macros"]
--------------------------------------------------
include-tagged::{doc-tests-file}[x-pack-{api}-response]
--------------------------------------------------

[id="{upid}-x-pack-{api}-async"]
==== Asynchronous Execution

This request can be executed asynchronously:

["source","java",subs="attributes,callouts,macros"]
--------------------------------------------------
include-tagged::{doc-tests-file}[x-pack-{api}-execute-async]
--------------------------------------------------
<1> The +{request}+ 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 +{response}+ looks like:

["source","java",subs="attributes,callouts,macros"]
--------------------------------------------------
include-tagged::{doc-tests-file}[x-pack-{api}-execute-listener]
--------------------------------------------------
<1> Called when the execution is successfully completed. The response is
provided as an argument
<2> Called in case of failure. The raised exception is provided as an argument