Merge branch 'master' into translog-no-ops

* master:
  Simplify Unicast Zen Ping (elastic#22277)
  Replace IndicesQueriesRegistry (elastic#22289)
  Fixed document mistake and fit for 5.1.1 API
  [TEST] improve error message in ESTestCase#assertWarnings
  [TEST] remove deleted test classes from checkstyle suppressions
  [TEST] make ESSingleNodeTestCase tests repeatable (elastic#22283)
  Link for setting page in elasticsearch.yml is outdated
  Factor out sort values from InternalSearchHit (elastic#22080)
  Add ID for percolate query to Java API docs
  x_refresh.yaml tests should use unique index names and doc ids to ease debugging
  IndicesStoreIntegrationIT should not use start recovery sending as an indication that the recovery started
  Added base class for testing aggregators and some initial tests for `terms`, `top_hits` and `min` aggregations.
  Add link to foreach processor to ingest-attachment.asciidoc

Author: jasontedor

buildSrc/src/main/resources/checkstyle_suppressions.xml

@@ -590,9 +590,6 @@
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]action[/\\]termvectors[/\\]TermVectorsUnitTests.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]aliases[/\\]IndexAliasesIT.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]bootstrap[/\\]JarHellTests.java" checks="LineLength" />
-  <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]bwcompat[/\\]BasicAnalysisBackwardCompatibilityIT.java" checks="LineLength" />
-  <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]bwcompat[/\\]BasicBackwardsCompatibilityIT.java" checks="LineLength" />
-  <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]bwcompat[/\\]GetIndexBackwardsCompatibilityIT.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]bwcompat[/\\]RestoreBackwardsCompatIT.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]client[/\\]AbstractClientHeadersTestCase.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]cluster[/\\]ClusterHealthIT.java" checks="LineLength" />
@@ -704,7 +701,6 @@
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]gateway[/\\]PriorityComparatorTests.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]gateway[/\\]QuorumGatewayIT.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]gateway[/\\]RecoverAfterNodesIT.java" checks="LineLength" />
-  <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]gateway[/\\]RecoveryBackwardsCompatibilityIT.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]gateway[/\\]RecoveryFromGatewayIT.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]gateway[/\\]ReplicaShardAllocatorTests.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]gateway[/\\]ReusePeerRecoverySharedTest.java" checks="LineLength" />
@@ -923,7 +919,6 @@
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]snapshots[/\\]DedicatedClusterSnapshotRestoreIT.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]snapshots[/\\]RepositoriesIT.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]snapshots[/\\]SharedClusterSnapshotRestoreIT.java" checks="LineLength" />
-  <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]snapshots[/\\]SnapshotBackwardsCompatibilityIT.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]snapshots[/\\]SnapshotUtilsTests.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]ESBlobStoreRepositoryIntegTestCase.java" checks="LineLength" />
   <suppress files="core[/\\]src[/\\]test[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]geo[/\\]RandomShapeGenerator.java" checks="LineLength" />
@@ -993,13 +988,8 @@
   <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]common[/\\]util[/\\]MockBigArrays.java" checks="LineLength" />
   <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]search[/\\]aggregations[/\\]bucket[/\\]script[/\\]NativeSignificanceScoreScriptWithParams.java" checks="LineLength" />
   <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]BackgroundIndexer.java" checks="LineLength" />
-  <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]CompositeTestCluster.java" checks="LineLength" />
   <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]CorruptionUtils.java" checks="LineLength" />
-  <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]ESBackcompatTestCase.java" checks="LineLength" />
   <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]ESIntegTestCase.java" checks="LineLength" />
-  <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]ESSingleNodeTestCase.java" checks="LineLength" />
-  <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]ESTestCase.java" checks="LineLength" />
-  <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]ExternalNode.java" checks="LineLength" />
   <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]IndexSettingsModule.java" checks="LineLength" />
   <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]InternalTestCluster.java" checks="LineLength" />
   <suppress files="test[/\\]framework[/\\]src[/\\]main[/\\]java[/\\]org[/\\]elasticsearch[/\\]test[/\\]MockIndexEventListener.java" checks="LineLength" />

core/src/main/java/org/elasticsearch/client/transport/TransportClientNodesService.java

@@ -101,6 +101,21 @@ final class TransportClientNodesService extends AbstractComponent implements Clo
 
     private final TransportClient.HostFailureListener hostFailureListener;
 
+    // TODO: migrate this to use low level connections and single type channels
+    /** {@link ConnectionProfile} to use when to connecting to the listed nodes and doing a liveness check */
+    private static final ConnectionProfile LISTED_NODES_PROFILE;
+
+    static {
+        ConnectionProfile.Builder builder = new ConnectionProfile.Builder();
+        builder.addConnections(1,
+            TransportRequestOptions.Type.BULK,
+            TransportRequestOptions.Type.PING,
+            TransportRequestOptions.Type.RECOVERY,
+            TransportRequestOptions.Type.REG,
+            TransportRequestOptions.Type.STATE);
+        LISTED_NODES_PROFILE = builder.build();
+    }
+
     TransportClientNodesService(Settings settings, TransportService transportService,
                                        ThreadPool threadPool, TransportClient.HostFailureListener hostFailureListener) {
         super(settings);
@@ -389,8 +404,8 @@ protected void doSample() {
                 if (!transportService.nodeConnected(listedNode)) {
                     try {
                         // its a listed node, light connect to it...
-                        logger.trace("connecting to listed node (light) [{}]", listedNode);
-                        transportService.connectToNode(listedNode, ConnectionProfile.LIGHT_PROFILE);
+                        logger.trace("connecting to listed node [{}]", listedNode);
+                        transportService.connectToNode(listedNode, LISTED_NODES_PROFILE);
                     } catch (Exception e) {
                         logger.info(
                             (Supplier<?>)
@@ -470,7 +485,7 @@ public void run() {
                                     } else {
                                         // its a listed node, light connect to it...
                                         logger.trace("connecting to listed node (light) [{}]", listedNode);
-                                        transportService.connectToNode(listedNode, ConnectionProfile.LIGHT_PROFILE);
+                                        transportService.connectToNode(listedNode, LISTED_NODES_PROFILE);
                                     }
                                 } catch (Exception e) {
                                     logger.debug(

core/src/main/java/org/elasticsearch/common/xcontent/XContentParserUtils.java

@@ -22,6 +22,7 @@
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.xcontent.XContentParser.Token;
 
+import java.io.IOException;
 import java.util.Locale;
 import java.util.function.Supplier;
 
@@ -34,6 +35,19 @@ public final class XContentParserUtils {
     private XContentParserUtils() {
     }
 
+    /**
+     * Makes sure that current token is of type {@link XContentParser.Token#FIELD_NAME} and the the field name is equal to the provided one
+     * @throws ParsingException if the token is not of type {@link XContentParser.Token#FIELD_NAME} or is not equal to the given field name
+     */
+    public static void ensureFieldName(XContentParser parser, Token token, String fieldName) throws IOException {
+        ensureExpectedToken(Token.FIELD_NAME, token, parser::getTokenLocation);
+        String currentName = parser.currentName();
+        if (currentName.equals(fieldName) == false) {
+            String message = "Failed to parse object: expecting field with name [%s] but found [%s]";
+            throw new ParsingException(parser.getTokenLocation(), String.format(Locale.ROOT, message, fieldName, currentName));
+        }
+    }
+
     /**
      * @throws ParsingException with a "unknown field found" reason
      */

core/src/main/java/org/elasticsearch/discovery/zen/ElectMasterService.java

@@ -24,7 +24,6 @@
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.common.component.AbstractComponent;
-import org.elasticsearch.common.inject.Inject;
 import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Setting.Property;
 import org.elasticsearch.common.settings.Settings;
@@ -174,7 +173,7 @@ public void logMinimumMasterNodesWarningIfNecessary(ClusterState oldState, Clust
      * Returns the given nodes sorted by likelihood of being elected as master, most likely first.
      * Non-master nodes are not removed but are rather put in the end
      */
-    public static List<DiscoveryNode> sortByMasterLikelihood(Iterable<DiscoveryNode> nodes) {
+    static List<DiscoveryNode> sortByMasterLikelihood(Iterable<DiscoveryNode> nodes) {
         ArrayList<DiscoveryNode> sortedNodes = CollectionUtils.iterableAsArrayList(nodes);
         CollectionUtil.introSort(sortedNodes, ElectMasterService::compareNodes);
         return sortedNodes;