Documented default values for index follow request parameters. (#37917)

docs/reference/ccr/apis/follow-request-body.asciidoc

@@ -1,3 +1,5 @@
+[role="xpack"]
+[testenv="platinum"]
 `max_read_request_operation_count`::
   (integer) the maximum number of operations to pull per read from the remote
   cluster
@@ -41,4 +43,62 @@
   remote cluster when the follower index is synchronized with the leader index;
   when the timeout has elapsed, the poll for operations will return to the
   follower so that it can update some statistics, and then the follower will
-  immediately attempt to read from the leader again
+  immediately attempt to read from the leader again
+
+===== Default values
+
+//////////////////////////
+
+[source,js]
+--------------------------------------------------
+PUT /follower_index/_ccr/follow
+{
+  "remote_cluster" : "remote_cluster",
+  "leader_index" : "leader_index"
+}
+--------------------------------------------------
+// CONSOLE
+// TESTSETUP
+// TEST[setup:remote_cluster_and_leader_index]
+
+[source,js]
+--------------------------------------------------
+POST /follower_index/_ccr/pause_follow
+--------------------------------------------------
+// CONSOLE
+// TEARDOWN
+
+[source,js]
+--------------------------------------------------
+GET /follower_index/_ccr/info?filter_path=follower_indices.parameters
+--------------------------------------------------
+// CONSOLE
+
+//////////////////////////
+
+The following output from the follow info api describes all the default
+values for the above described index follow request parameters:
+
+[source,js]
+--------------------------------------------------
+{
+  "follower_indices" : [
+    {
+      "parameters" : {
+        "max_read_request_operation_count" : 5120,
+        "max_read_request_size" : "32mb",
+        "max_outstanding_read_requests" : 12,
+        "max_write_request_operation_count" : 5120,
+        "max_write_request_size" : "9223372036854775807b",
+        "max_outstanding_write_requests" : 9,
+        "max_write_buffer_count" : 2147483647,
+        "max_write_buffer_size" : "512mb",
+        "max_retry_delay" : "500ms",
+        "read_poll_timeout" : "1m"
+      }
+    }
+  ]
+}
+
+--------------------------------------------------
+// TESTRESPONSE