Respect default search timeout

The default search timeout is not respected because the timeout is
unconditionally set from the query. This commit fixes this issue, and
adds a test that the default search timeout is correctly attached to the
search context.

Relates #21599

Author: jasontedor

core/src/main/java/org/elasticsearch/search/SearchService.java

@@ -25,8 +25,8 @@
 import org.apache.lucene.util.IOUtils;
 import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.ExceptionsHelper;
-import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.action.search.SearchTask;
+import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.Nullable;
@@ -85,7 +85,6 @@
 import org.elasticsearch.search.sort.SortBuilder;
 import org.elasticsearch.search.suggest.Suggest;
 import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
-import org.elasticsearch.tasks.Task;
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.threadpool.ThreadPool.Cancellable;
 import org.elasticsearch.threadpool.ThreadPool.Names;
@@ -722,7 +721,9 @@ private void parseSource(DefaultSearchContext context, SearchSourceBuilder sourc
         if (source.profile()) {
             context.setProfilers(new Profilers(context.searcher()));
         }
-        context.timeout(source.timeout());
+        if (source.timeout() != null) {
+            context.timeout(source.timeout());
+        }
         context.terminateAfter(source.terminateAfter());
         if (source.aggregations() != null) {
             try {

core/src/test/java/org/elasticsearch/search/SearchServiceTests.java

@@ -31,6 +31,8 @@
 import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.index.IndexService;
 import org.elasticsearch.index.query.AbstractQueryBuilder;
@@ -44,6 +46,7 @@
 import org.elasticsearch.search.builder.SearchSourceBuilder;
 import org.elasticsearch.search.fetch.ShardFetchRequest;
 import org.elasticsearch.search.internal.AliasFilter;
+import org.elasticsearch.search.internal.SearchContext;
 import org.elasticsearch.search.internal.ShardSearchLocalRequest;
 import org.elasticsearch.search.query.QuerySearchResultProvider;
 import org.elasticsearch.test.ESSingleNodeTestCase;
@@ -59,6 +62,7 @@
 import static java.util.Collections.singletonList;
 import static org.elasticsearch.action.support.WriteRequest.RefreshPolicy.IMMEDIATE;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
+import static org.hamcrest.CoreMatchers.equalTo;
 import static org.hamcrest.Matchers.is;
 import static org.hamcrest.Matchers.notNullValue;
 
@@ -74,6 +78,11 @@ protected Collection<Class<? extends Plugin>> getPlugins() {
         return pluginList(FailOnRewriteQueryPlugin.class);
     }
 
+    @Override
+    protected Settings nodeSettings() {
+        return Settings.builder().put("search.default_search_timeout", "5s").build();
+    }
+
     public void testClearOnClose() throws ExecutionException, InterruptedException {
         createIndex("index");
         client().prepareIndex("index", "type", "1").setSource("field", "value").setRefreshPolicy(IMMEDIATE).get();
@@ -197,6 +206,40 @@ public void onFailure(Exception e) {
         }
     }
 
+    public void testTimeout() throws IOException {
+        createIndex("index");
+        final SearchService service = getInstanceFromNode(SearchService.class);
+        final IndicesService indicesService = getInstanceFromNode(IndicesService.class);
+        final IndexService indexService = indicesService.indexServiceSafe(resolveIndex("index"));
+        final IndexShard indexShard = indexService.getShard(0);
+        final SearchContext contextWithDefaultTimeout = service.createContext(
+            new ShardSearchLocalRequest(
+                indexShard.shardId(),
+                1,
+                SearchType.DEFAULT,
+                new SearchSourceBuilder(),
+                new String[0],
+                false,
+                new AliasFilter(null, Strings.EMPTY_ARRAY)),
+            null);
+        // the search context should inherit the default timeout
+        assertThat(contextWithDefaultTimeout.timeout(), equalTo(TimeValue.timeValueSeconds(5)));
+
+        final long seconds = randomIntBetween(6, 10);
+        final SearchContext context = service.createContext(
+            new ShardSearchLocalRequest(
+                indexShard.shardId(),
+                1,
+                SearchType.DEFAULT,
+                new SearchSourceBuilder().timeout(TimeValue.timeValueSeconds(seconds)),
+                new String[0],
+                false,
+                new AliasFilter(null, Strings.EMPTY_ARRAY)),
+            null);
+        // the search context should inherit the query timeout
+        assertThat(context.timeout(), equalTo(TimeValue.timeValueSeconds(seconds)));
+    }
+
     public static class FailOnRewriteQueryPlugin extends Plugin implements SearchPlugin {
         @Override
         public List<QuerySpec<?>> getQueries() {