From 4544586d4781e6a8cedb15bd28d667cf3e6e9419 Mon Sep 17 00:00:00 2001
From: Daniel Mitterdorfer <daniel.mitterdorfer@elastic.co>
Date: Mon, 12 Feb 2024 10:37:20 +0100
Subject: [PATCH] [Profiling] Return early when no data are found

With this commit we check whether any documents match when custom
indices are provided and terminate early if the response is empty.
---
 .../profiling/GetStackTracesActionIT.java     | 21 +++++++++++++++++++
 .../TransportGetStackTracesAction.java        |  6 +++++-
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/x-pack/plugin/profiling/src/internalClusterTest/java/org/elasticsearch/xpack/profiling/GetStackTracesActionIT.java b/x-pack/plugin/profiling/src/internalClusterTest/java/org/elasticsearch/xpack/profiling/GetStackTracesActionIT.java
index d42bc59e7dbb5..27fd5f58d755e 100644
--- a/x-pack/plugin/profiling/src/internalClusterTest/java/org/elasticsearch/xpack/profiling/GetStackTracesActionIT.java
+++ b/x-pack/plugin/profiling/src/internalClusterTest/java/org/elasticsearch/xpack/profiling/GetStackTracesActionIT.java
@@ -176,4 +176,25 @@ public void testGetStackTracesFromAPMNoMatch() throws Exception {
         GetStackTracesResponse response = client().execute(GetStackTracesAction.INSTANCE, request).get();
         assertEquals(0, response.getTotalFrames());
     }
+
+    public void testGetStackTracesFromAPMIndexNotAvailable() throws Exception {
+        TermQueryBuilder query = QueryBuilders.termQuery("transaction.name", "nonExistingTransaction");
+
+        GetStackTracesRequest request = new GetStackTracesRequest(
+            null,
+            1.0d,
+            1.0d,
+            1.0d,
+            query,
+            new String[] { "non-existing-apm-index-*" },
+            "transaction.profiler_stack_trace_ids",
+            null,
+            null,
+            null,
+            null,
+            null
+        );
+        GetStackTracesResponse response = client().execute(GetStackTracesAction.INSTANCE, request).get();
+        assertEquals(0, response.getTotalFrames());
+    }
 }
diff --git a/x-pack/plugin/profiling/src/main/java/org/elasticsearch/xpack/profiling/TransportGetStackTracesAction.java b/x-pack/plugin/profiling/src/main/java/org/elasticsearch/xpack/profiling/TransportGetStackTracesAction.java
index d49f42ce69737..a0547b39388d8 100644
--- a/x-pack/plugin/profiling/src/main/java/org/elasticsearch/xpack/profiling/TransportGetStackTracesAction.java
+++ b/x-pack/plugin/profiling/src/main/java/org/elasticsearch/xpack/profiling/TransportGetStackTracesAction.java
@@ -242,7 +242,11 @@ private void searchGenericEvents(
                     request.getIndices(),
                     responseBuilder.getSamplingRate()
                 );
-                searchGenericEventGroupedByStackTrace(submitTask, client, request, submitListener, responseBuilder);
+                if (sampleCount > 0) {
+                    searchGenericEventGroupedByStackTrace(submitTask, client, request, submitListener, responseBuilder);
+                } else {
+                    submitListener.onResponse(responseBuilder.build());
+                }
             }, submitListener::onFailure));
     }