Return partial failures if search was cancelled.

modules/reindex/src/yamlRestTest/resources/rest-api-spec/test/reindex/35_search_failures.yml

@@ -1,8 +1,5 @@
 ---
 "Response format for search failures":
-  - skip:
-      version: "all"
-      reason: "awaits fix of https://github.com/elastic/elasticsearch/pull/64382"
   - do:
       indices.create:
         index: source

server/src/internalClusterTest/java/org/elasticsearch/search/SearchCancellationIT.java

@@ -67,6 +67,7 @@
 import static org.elasticsearch.search.SearchCancellationIT.ScriptedBlockPlugin.SCRIPT_NAME;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertFailures;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertNoFailures;
+import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.hasSize;
@@ -311,12 +312,12 @@ public void testCancelFailedSearchWhenPartialResultDisallowed() throws Exception
             .build());
         indexTestData();
         Thread searchThread = new Thread(() -> {
-            expectThrows(Exception.class, () -> {
+            SearchPhaseExecutionException e = expectThrows(SearchPhaseExecutionException.class, () ->
                 client().prepareSearch("test")
                     .setSearchType(SearchType.QUERY_THEN_FETCH)
                     .setQuery(scriptQuery(new Script(ScriptType.INLINE, "mockscript", SCRIPT_NAME, Collections.emptyMap())))
-                    .setAllowPartialSearchResults(false).setSize(1000).get();
-            });
+                    .setAllowPartialSearchResults(false).setSize(1000).get());
+            assertThat(e.getMessage(), containsString("Partial shards failure"));
         });
         searchThread.start();
         try {

server/src/main/java/org/elasticsearch/action/search/AbstractSearchAsyncAction.java

@@ -314,13 +314,16 @@ public boolean isForceExecution() {
         });
     }
 
+
     @Override
     public final void executeNextPhase(SearchPhase currentPhase, SearchPhase nextPhase) {
-        /* This is the main search phase transition where we move to the next phase. At this point we check if there is
-         * at least one successful operation left and if so we move to the next phase. If not we immediately fail the
-         * search phase as "all shards failed"*/
-        if (successfulOps.get() == 0) { // we have 0 successful results that means we shortcut stuff and return a failure
-            final ShardOperationFailedException[] shardSearchFailures = ExceptionsHelper.groupBy(buildShardFailures());
+        /* This is the main search phase transition where we move to the next phase. If all shards
+         * failed or if there was a failure and partial results are not allowed, then we immediately
+         * fail. Otherwise we continue to the next phase.
+         */
+        ShardOperationFailedException[] shardSearchFailures = buildShardFailures();
+        if (shardSearchFailures.length == getNumShards()) {
+            shardSearchFailures = ExceptionsHelper.groupBy(shardSearchFailures);
             Throwable cause = shardSearchFailures.length == 0 ? null :
                 ElasticsearchException.guessRootCauses(shardSearchFailures[0].getCause())[0];
             logger.debug(() -> new ParameterizedMessage("All shards failed for phase: [{}]", getName()), cause);
@@ -331,7 +334,6 @@ public final void executeNextPhase(SearchPhase currentPhase, SearchPhase nextPha
             if (allowPartialResults == false && successfulOps.get() != getNumShards()) {
                 // check if there are actual failures in the atomic array since
                 // successful retries can reset the failures to null
-                ShardOperationFailedException[] shardSearchFailures = buildShardFailures();
                 if (shardSearchFailures.length > 0) {
                     if (logger.isDebugEnabled()) {
                         int numShardFailures = shardSearchFailures.length;