diff --git a/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/AsyncSearchTask.java b/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/AsyncSearchTask.java
index d6ee78eaf80..8bb254a2174 100644
--- a/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/AsyncSearchTask.java
+++ b/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/AsyncSearchTask.java
@@ -134,9 +134,9 @@ final class AsyncSearchTask extends SearchTask implements AsyncTask {
     /**
      * Cancels the running task and its children.
      */
-    public void cancelTask(Runnable runnable) {
+    public void cancelTask(Runnable runnable, String reason) {
         if (isCancelled() == false && isCancelling.compareAndSet(false, true)) {
-            CancelTasksRequest req = new CancelTasksRequest().setTaskId(searchId.getTaskId());
+            CancelTasksRequest req = new CancelTasksRequest().setTaskId(searchId.getTaskId()).setReason(reason);
             client.admin().cluster().cancelTasks(req, new ActionListener<CancelTasksResponse>() {
                 @Override
                 public void onResponse(CancelTasksResponse cancelTasksResponse) {
@@ -316,8 +316,6 @@ final class AsyncSearchTask extends SearchTask implements AsyncTask {
         return searchResponse.get().toAsyncSearchResponseWithHeaders(this, expirationTimeMillis);
     }
 
-
-
     // checks if the search task should be cancelled
     private synchronized void checkCancellation() {
         long now = System.currentTimeMillis();
@@ -326,7 +324,7 @@ final class AsyncSearchTask extends SearchTask implements AsyncTask {
             // we cancel the search task if the initial submit task was cancelled,
             // this is needed because the task cancellation mechanism doesn't
             // handle the cancellation of grand-children.
-            cancelTask(() -> {});
+            cancelTask(() -> {}, checkSubmitCancellation.getAsBoolean() ? "submit was cancelled" : "async search has expired");
         }
     }
 
diff --git a/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/TransportDeleteAsyncSearchAction.java b/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/TransportDeleteAsyncSearchAction.java
index ae628edc28e..aa68ff53047 100644
--- a/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/TransportDeleteAsyncSearchAction.java
+++ b/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/TransportDeleteAsyncSearchAction.java
@@ -90,7 +90,7 @@ public class TransportDeleteAsyncSearchAction extends HandledTransportAction<Del
                             logger.error(() -> new ParameterizedMessage("failed to clean async-search [{}]", searchId.getEncoded()), exc);
                             listener.onFailure(exc);
                         }
-                    })));
+                    })), "cancelled by user");
         } else {
             // the task was not found (already cancelled, already completed, or invalid id?)
             // we fail if the response is not found in the index
diff --git a/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/TransportSubmitAsyncSearchAction.java b/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/TransportSubmitAsyncSearchAction.java
index 10b937f7119..ea93598f68e 100644
--- a/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/TransportSubmitAsyncSearchAction.java
+++ b/x-pack/plugin/async-search/src/main/java/org/elasticsearch/xpack/search/TransportSubmitAsyncSearchAction.java
@@ -91,7 +91,8 @@ public class TransportSubmitAsyncSearchAction extends HandledTransportAction<Sub
                                 // the user cancelled the submit so we don't store anything
                                 // and propagate the failure
                                 Exception cause = new TaskCancelledException(submitTask.getReasonCancelled());
-                                onFatalFailure(searchTask, cause, searchResponse.isRunning(), submitListener);
+                                onFatalFailure(searchTask, cause, searchResponse.isRunning(),
+                                    "submit task is cancelled", submitListener);
                             } else {
                                 final String docId = searchTask.getExecutionId().getDocId();
                                 // creates the fallback response if the node crashes/restarts in the middle of the request
@@ -117,12 +118,13 @@ public class TransportSubmitAsyncSearchAction extends HandledTransportAction<Sub
 
                                         @Override
                                         public void onFailure(Exception exc) {
-                                            onFatalFailure(searchTask, exc, searchResponse.isRunning(), submitListener);
+                                            onFatalFailure(searchTask, exc, searchResponse.isRunning(),
+                                                "unable to store initial response", submitListener);
                                         }
                                     });
                             }
                         } catch (Exception exc) {
-                            onFatalFailure(searchTask, exc, searchResponse.isRunning(), submitListener);
+                            onFatalFailure(searchTask, exc, searchResponse.isRunning(), "generic error", submitListener);
                         }
                     } else {
                         // the task completed within the timeout so the response is sent back to the user
@@ -157,7 +159,8 @@ public class TransportSubmitAsyncSearchAction extends HandledTransportAction<Sub
         return searchRequest;
     }
 
-    private void onFatalFailure(AsyncSearchTask task, Exception error, boolean shouldCancel, ActionListener<AsyncSearchResponse> listener) {
+    private void onFatalFailure(AsyncSearchTask task, Exception error, boolean shouldCancel, String cancelReason,
+                                ActionListener<AsyncSearchResponse> listener) {
         if (shouldCancel && task.isCancelled() == false) {
             task.cancelTask(() -> {
                 try {
@@ -165,7 +168,7 @@ public class TransportSubmitAsyncSearchAction extends HandledTransportAction<Sub
                 } finally {
                     listener.onFailure(error);
                 }
-            });
+            }, "fatal failure: " + cancelReason);
         } else {
             try {
                 task.addCompletionListener(finalResponse -> taskManager.unregister(task));