Add HLRC docs

Author: jasontedor

client/rest-high-level/src/test/java/org/elasticsearch/client/documentation/CCRDocumentationIT.java

@@ -436,12 +436,12 @@ public void testForgetFollower() throws InterruptedException, IOException {
         final String leaderCluster = "local";
 
         // tag::ccr-forget-follower-request
-        final ForgetFollowerRequest request = new ForgetFollowerRequest( // <1>
-                followerCluster,
-                followerIndex,
-                followerIndexUUID,
-                leaderCluster,
-                leaderIndex);
+        final ForgetFollowerRequest request = new ForgetFollowerRequest(
+                followerCluster, // <1>
+                followerIndex, // <2>
+                followerIndexUUID, // <3>
+                leaderCluster, // <4>
+                leaderIndex); // <5>
         // end::ccr-forget-follower-request
 
         // tag::ccr-forget-follower-execute
@@ -452,11 +452,11 @@ public void testForgetFollower() throws InterruptedException, IOException {
 
         // tag::ccr-forget-follower-response
         final BroadcastResponse.Shards shards = response.shards(); // <1>
-        final int total = shards.total();
-        final int successful = shards.successful();
-        final int skipped = shards.skipped();
-        final int failed = shards.failed();
-        shards.failures().forEach(failure -> {});
+        final int total = shards.total(); // <2>
+        final int successful = shards.successful(); // <3>
+        final int skipped = shards.skipped(); // <4>
+        final int failed = shards.failed(); // <5>
+        shards.failures().forEach(failure -> {}); // <6>
         // end::ccr-forget-follower-response
 
         // tag::ccr-forget-follower-execute-listener

docs/java-rest/high-level/ccr/forget_follower.asciidoc

@@ -0,0 +1,45 @@
+--
+:api: ccr-forget-follower
+:request: ForgetFollowerRequest
+:response: BroadcastResponse
+--
+
+[id="{upid}-{api}"]
+=== Forget Follower API
+
+[id="{upid}-{api}-request"]
+==== Request
+
+The Forget Follower API allows you to manually remove the follower retention
+leases from the leader. Note that these retention leases are automatically
+managed by the following index. This API exists only for cases when invoking
+the unfollow API on the follower index is unable to remove the follower
+retention leases.
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests-file}[{api}-request]
+--------------------------------------------------
+<1> The name of the cluster containing the follower index.
+<2> The name of the follower index.
+<3> The UUID of the follower index (can be obtained from index stats).
+<4> The alias of the remote cluster containing the leader index.
+<5> The name of the leader index.
+
+[id="{upid}-{api}-response"]
+==== Response
+
+The returned +{response}+ indicates if the response was successful.
+
+["source","java",subs="attributes,callouts,macros"]
+--------------------------------------------------
+include-tagged::{doc-tests-file}[{api}-response]
+--------------------------------------------------
+<1> The high-level shards summary.
+<2> The total number of shards the request was executed on.
+<3> The total number of shards the request was successful on.
+<4> The total number of shards the request was skipped on (should always be zero).
+<5> The total number of shards the request failed on.
+<6> The shard-level failures.
+
+include::../execution.asciidoc[]

docs/java-rest/high-level/supported-apis.asciidoc

@@ -502,6 +502,7 @@ The Java High Level REST Client supports the following CCR APIs:
 * <<{upid}-ccr-pause-follow>>
 * <<{upid}-ccr-resume-follow>>
 * <<{upid}-ccr-unfollow>>
+* <<{upid}-ccr-forget-follower>>
 * <<{upid}-ccr-put-auto-follow-pattern>>
 * <<{upid}-ccr-delete-auto-follow-pattern>>
 * <<{upid}-ccr-get-auto-follow-pattern>>