Allow partial result by default in ES|QL

Author: dnhatn

test/external-modules/esql-heap-attack/src/javaRestTest/java/org/elasticsearch/xpack/esql/heap_attack/HeapAttackIT.java

@@ -117,6 +117,7 @@ public void testSortByManyLongsTooMuchMemoryAsync() throws IOException {
         initManyLongs();
         Request request = new Request("POST", "/_query/async");
         request.addParameter("error_trace", "");
+        request.addParameter("allow_partial_results", Boolean.toString(false));
         request.setJsonEntity(makeSortByManyLongs(5000).toString().replace("\n", "\\n"));
         request.setOptions(
             RequestOptions.DEFAULT.toBuilder()

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/action/RequestXContent.java

@@ -85,7 +85,6 @@ String fields() {
     static final ParseField WAIT_FOR_COMPLETION_TIMEOUT = new ParseField("wait_for_completion_timeout");
     static final ParseField KEEP_ALIVE = new ParseField("keep_alive");
     static final ParseField KEEP_ON_COMPLETION = new ParseField("keep_on_completion");
-    static final ParseField ALLOW_PARTIAL_RESULTS = new ParseField("allow_partial_results");
 
     private static final ObjectParser<EsqlQueryRequest, Void> SYNC_PARSER = objectParserSync(EsqlQueryRequest::syncEsqlQueryRequest);
     private static final ObjectParser<EsqlQueryRequest, Void> ASYNC_PARSER = objectParserAsync(EsqlQueryRequest::asyncEsqlQueryRequest);
@@ -115,7 +114,6 @@ private static void objectParserCommon(ObjectParser<EsqlQueryRequest, ?> parser)
         parser.declareString((request, localeTag) -> request.locale(Locale.forLanguageTag(localeTag)), LOCALE_FIELD);
         parser.declareBoolean(EsqlQueryRequest::profile, PROFILE_FIELD);
         parser.declareField((p, r, c) -> new ParseTables(r, p).parseTables(), TABLES_FIELD, ObjectParser.ValueType.OBJECT);
-        parser.declareBoolean(EsqlQueryRequest::allowPartialResults, ALLOW_PARTIAL_RESULTS);
     }
 
     private static ObjectParser<EsqlQueryRequest, Void> objectParserSync(Supplier<EsqlQueryRequest> supplier) {

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/action/RestEsqlQueryAction.java

@@ -51,6 +51,7 @@ protected RestChannelConsumer prepareRequest(RestRequest request, NodeClient cli
     }
 
     protected static RestChannelConsumer restChannelConsumer(EsqlQueryRequest esqlRequest, RestRequest request, NodeClient client) {
+        esqlRequest.allowPartialResults(request.paramAsBoolean("allow_partial_results", true));
         LOGGER.debug("Beginning execution of ESQL query.\nQuery string: [{}]", esqlRequest.query());
 
         return channel -> {