Remove `InternalTestCluster.startNode(s)Async` (#21846)

Since the removal of local discovery of #https://github.com/elastic/elasticsearch/pull/20960 we rely on minimum master nodes to be set in our test cluster. The settings is automatically managed by the cluster (by default) but current management doesn't work with concurrent single node async starting. On the other hand, with `MockZenPing` and the `discovery.initial_state_timeout` set to `0s` node starting and joining is very fast making async starting an unneeded complexity. Test that still need async starting could, in theory, still do so themselves via background threads.

Note that this change also removes the usage of `INITIAL_STATE_TIMEOUT_SETTINGS` as the starting of nodes is done concurrently (but building them is sequential)

30 files changed, 232 insertions, 362 deletions

diff --git a/core/src/test/java/org/elasticsearch/action/admin/cluster/allocation/ClusterAllocationExplainIT.java b/core/src/test/java/org/elasticsearch/action/admin/cluster/allocation/ClusterAllocationExplainIT.java
index 102e16691d..33f683b458 100644
--- a/core/src/test/java/org/elasticsearch/action/admin/cluster/allocation/ClusterAllocationExplainIT.java
+++ b/core/src/test/java/org/elasticsearch/action/admin/cluster/allocation/ClusterAllocationExplainIT.java
@@ -45,7 +45,7 @@ public final class ClusterAllocationExplainIT extends ESIntegTestCase {
     @TestLogging("_root:DEBUG")
     public void testDelayShards() throws Exception {
         logger.info("--> starting 3 nodes");
-        internalCluster().startNodesAsync(3).get();
+        internalCluster().startNodes(3);
 
         // Wait for all 3 nodes to be up
         logger.info("--> waiting for 3 nodes to be up");
diff --git a/core/src/test/java/org/elasticsearch/action/admin/cluster/stats/ClusterStatsIT.java b/core/src/test/java/org/elasticsearch/action/admin/cluster/stats/ClusterStatsIT.java
index aa73eafb49..26a882f004 100644
--- a/core/src/test/java/org/elasticsearch/action/admin/cluster/stats/ClusterStatsIT.java
+++ b/core/src/test/java/org/elasticsearch/action/admin/cluster/stats/ClusterStatsIT.java
@@ -162,7 +162,7 @@ public class ClusterStatsIT extends ESIntegTestCase {
     }
 
     public void testValuesSmokeScreen() throws IOException, ExecutionException, InterruptedException {
-        internalCluster().startNodesAsync(randomIntBetween(1, 3)).get();
+        internalCluster().startNodes(randomIntBetween(1, 3));
         index("test1", "type", "1", "f", "f");
 
         ClusterStatsResponse response = client().admin().cluster().prepareClusterStats().get();
@@ -202,7 +202,7 @@ public class ClusterStatsIT extends ESIntegTestCase {
 
     public void testAllocatedProcessors() throws Exception {
         // start one node with 7 processors.
-        internalCluster().startNodesAsync(Settings.builder().put(EsExecutors.PROCESSORS_SETTING.getKey(), 7).build()).get();
+        internalCluster().startNode(Settings.builder().put(EsExecutors.PROCESSORS_SETTING.getKey(), 7).build());
         waitForNodes(1);
 
         ClusterStatsResponse response = client().admin().cluster().prepareClusterStats().get();
diff --git a/core/src/test/java/org/elasticsearch/action/support/master/IndexingMasterFailoverIT.java b/core/src/test/java/org/elasticsearch/action/support/master/IndexingMasterFailoverIT.java
index 7c764ed172..b35aac5f95 100644
--- a/core/src/test/java/org/elasticsearch/action/support/master/IndexingMasterFailoverIT.java
+++ b/core/src/test/java/org/elasticsearch/action/support/master/IndexingMasterFailoverIT.java
@@ -75,7 +75,7 @@ public class IndexingMasterFailoverIT extends ESIntegTestCase {
                 .put(ElectMasterService.DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.getKey(), 2)
                 .build();
 
-        internalCluster().startMasterOnlyNodesAsync(3, sharedSettings).get();
+        internalCluster().startMasterOnlyNodes(3, sharedSettings);
 
         String dataNode = internalCluster().startDataOnlyNode(sharedSettings);
 
diff --git a/core/src/test/java/org/elasticsearch/bwcompat/OldIndexBackwardsCompatibilityIT.java b/core/src/test/java/org/elasticsearch/bwcompat/OldIndexBackwardsCompatibilityIT.java
index 1fd71c7ae5..307b47edac 100644
--- a/core/src/test/java/org/elasticsearch/bwcompat/OldIndexBackwardsCompatibilityIT.java
+++ b/core/src/test/java/org/elasticsearch/bwcompat/OldIndexBackwardsCompatibilityIT.java
@@ -61,7 +61,6 @@ import org.elasticsearch.search.aggregations.bucket.terms.Terms;
 import org.elasticsearch.search.sort.SortOrder;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.test.InternalSettingsPlugin;
-import org.elasticsearch.test.InternalTestCluster;
 import org.elasticsearch.test.OldIndexUtils;
 import org.elasticsearch.test.VersionUtils;
 import org.elasticsearch.test.hamcrest.ElasticsearchAssertions;
@@ -129,24 +128,23 @@ public class OldIndexBackwardsCompatibilityIT extends ESIntegTestCase {
     }
 
     void setupCluster() throws Exception {
-        InternalTestCluster.Async<List<String>> replicas = internalCluster().startNodesAsync(1); // for replicas
+        List<String> replicas = internalCluster().startNodes(1); // for replicas
 
         Path baseTempDir = createTempDir();
         // start single data path node
         Settings.Builder nodeSettings = Settings.builder()
                 .put(Environment.PATH_DATA_SETTING.getKey(), baseTempDir.resolve("single-path").toAbsolutePath())
                 .put(Node.NODE_MASTER_SETTING.getKey(), false); // workaround for dangling index loading issue when node is master
-        InternalTestCluster.Async<String> singleDataPathNode = internalCluster().startNodeAsync(nodeSettings.build());
+        singleDataPathNodeName = internalCluster().startNode(nodeSettings);
 
         // start multi data path node
         nodeSettings = Settings.builder()
                 .put(Environment.PATH_DATA_SETTING.getKey(), baseTempDir.resolve("multi-path1").toAbsolutePath() + "," + baseTempDir
                         .resolve("multi-path2").toAbsolutePath())
                 .put(Node.NODE_MASTER_SETTING.getKey(), false); // workaround for dangling index loading issue when node is master
-        InternalTestCluster.Async<String> multiDataPathNode = internalCluster().startNodeAsync(nodeSettings.build());
+        multiDataPathNodeName = internalCluster().startNode(nodeSettings);
 
         // find single data path dir
-        singleDataPathNodeName = singleDataPathNode.get();
         Path[] nodePaths = internalCluster().getInstance(NodeEnvironment.class, singleDataPathNodeName).nodeDataPaths();
         assertEquals(1, nodePaths.length);
         singleDataPath = nodePaths[0].resolve(NodeEnvironment.INDICES_FOLDER);
@@ -155,7 +153,6 @@ public class OldIndexBackwardsCompatibilityIT extends ESIntegTestCase {
         logger.info("--> Single data path: {}", singleDataPath);
 
         // find multi data path dirs
-        multiDataPathNodeName = multiDataPathNode.get();
         nodePaths = internalCluster().getInstance(NodeEnvironment.class, multiDataPathNodeName).nodeDataPaths();
         assertEquals(2, nodePaths.length);
         multiDataPath = new Path[]{nodePaths[0].resolve(NodeEnvironment.INDICES_FOLDER),
@@ -165,8 +162,6 @@ public class OldIndexBackwardsCompatibilityIT extends ESIntegTestCase {
         Files.createDirectories(multiDataPath[0]);
         Files.createDirectories(multiDataPath[1]);
         logger.info("--> Multi data paths: {}, {}", multiDataPath[0], multiDataPath[1]);
-
-        replicas.get(); // wait for replicas
     }
 
     void upgradeIndexFolder() throws Exception {
diff --git a/core/src/test/java/org/elasticsearch/cluster/ClusterInfoServiceIT.java b/core/src/test/java/org/elasticsearch/cluster/ClusterInfoServiceIT.java
index d7a62ca7f1..3d3e87db08 100644
--- a/core/src/test/java/org/elasticsearch/cluster/ClusterInfoServiceIT.java
+++ b/core/src/test/java/org/elasticsearch/cluster/ClusterInfoServiceIT.java
@@ -126,7 +126,7 @@ public class ClusterInfoServiceIT extends ESIntegTestCase {
     }
 
     public void testClusterInfoServiceCollectsInformation() throws Exception {
-        internalCluster().startNodesAsync(2).get();
+        internalCluster().startNodes(2);
         assertAcked(prepareCreate("test").setSettings(Settings.builder()
                 .put(Store.INDEX_STORE_STATS_REFRESH_INTERVAL_SETTING.getKey(), 0)
                 .put(EnableAllocationDecider.INDEX_ROUTING_REBALANCE_ENABLE_SETTING.getKey(), EnableAllocationDecider.Rebalance.NONE).build()));
@@ -174,10 +174,9 @@ public class ClusterInfoServiceIT extends ESIntegTestCase {
     }
 
     public void testClusterInfoServiceInformationClearOnError() throws InterruptedException, ExecutionException {
-        internalCluster().startNodesAsync(2,
+        internalCluster().startNodes(2,
                 // manually control publishing
-                Settings.builder().put(InternalClusterInfoService.INTERNAL_CLUSTER_INFO_UPDATE_INTERVAL_SETTING.getKey(), "60m").build())
-                .get();
+                Settings.builder().put(InternalClusterInfoService.INTERNAL_CLUSTER_INFO_UPDATE_INTERVAL_SETTING.getKey(), "60m").build());
         prepareCreate("test").setSettings(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 1).get();
         ensureGreen("test");
         InternalTestCluster internalTestCluster = internalCluster();
diff --git a/core/src/test/java/org/elasticsearch/cluster/MinimumMasterNodesIT.java b/core/src/test/java/org/elasticsearch/cluster/MinimumMasterNodesIT.java
index 257b80663a..8f76581ae3 100644
--- a/core/src/test/java/org/elasticsearch/cluster/MinimumMasterNodesIT.java
+++ b/core/src/test/java/org/elasticsearch/cluster/MinimumMasterNodesIT.java
@@ -24,7 +24,6 @@ import org.elasticsearch.client.Client;
 import org.elasticsearch.cluster.metadata.MetaData;
 import org.elasticsearch.cluster.service.ClusterService;
 import org.elasticsearch.common.Priority;
-import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.discovery.Discovery;
@@ -202,22 +201,19 @@ public class MinimumMasterNodesIT extends ESIntegTestCase {
                 .build();
 
         logger.info("--> start first 2 nodes");
-        internalCluster().startNodesAsync(2, settings).get();
+        internalCluster().startNodes(2, settings);
 
         ClusterState state;
 
-        assertBusy(new Runnable() {
-            @Override
-            public void run() {
-                for (Client client : clients()) {
-                    ClusterState state = client.admin().cluster().prepareState().setLocal(true).execute().actionGet().getState();
-                    assertThat(state.blocks().hasGlobalBlock(DiscoverySettings.NO_MASTER_BLOCK_ID), equalTo(true));
-                }
+        assertBusy(() -> {
+            for (Client client : clients()) {
+                ClusterState state1 = client.admin().cluster().prepareState().setLocal(true).execute().actionGet().getState();
+                assertThat(state1.blocks().hasGlobalBlock(DiscoverySettings.NO_MASTER_BLOCK_ID), equalTo(true));
             }
         });
 
         logger.info("--> start two more nodes");
-        internalCluster().startNodesAsync(2, settings).get();
+        internalCluster().startNodes(2, settings);
 
         ensureGreen();
         ClusterHealthResponse clusterHealthResponse = client().admin().cluster().prepareHealth().setWaitForEvents(Priority.LANGUID).setWaitForNodes("4").execute().actionGet();
@@ -252,7 +248,7 @@ public class MinimumMasterNodesIT extends ESIntegTestCase {
         assertNoMasterBlockOnAllNodes();
 
         logger.info("--> start back the 2 nodes ");
-        String[] newNodes = internalCluster().startNodesAsync(2, settings).get().toArray(Strings.EMPTY_ARRAY);
+        String[] newNodes = internalCluster().startNodes(2, settings).stream().toArray(String[]::new);
 
         ensureGreen();
         clusterHealthResponse = client().admin().cluster().prepareHealth().setWaitForNodes("4").execute().actionGet();
@@ -338,7 +334,7 @@ public class MinimumMasterNodesIT extends ESIntegTestCase {
 
 
         logger.info("--> starting [{}] nodes. min_master_nodes set to [{}]", nodeCount, initialMinMasterNodes);
-        internalCluster().startNodesAsync(nodeCount, settings.build()).get();
+        internalCluster().startNodes(nodeCount, settings.build());
 
         logger.info("--> waiting for nodes to join");
         assertFalse(client().admin().cluster().prepareHealth().setWaitForNodes(Integer.toString(nodeCount)).get().isTimedOut());
@@ -371,7 +367,7 @@ public class MinimumMasterNodesIT extends ESIntegTestCase {
                 .put(ElectMasterService.DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.getKey(), 2)
                 .put(DiscoverySettings.COMMIT_TIMEOUT_SETTING.getKey(), "100ms") // speed things up
                 .build();
-        internalCluster().startNodesAsync(3, settings).get();
+        internalCluster().startNodes(3, settings);
         ensureGreen(); // ensure cluster state is recovered before we disrupt things
 
         final String master = internalCluster().getMasterName();
diff --git a/core/src/test/java/org/elasticsearch/cluster/UpdateSettingsValidationIT.java b/core/src/test/java/org/elasticsearch/cluster/UpdateSettingsValidationIT.java
index 9613128a00..a21f61ce8a 100644
--- a/core/src/test/java/org/elasticsearch/cluster/UpdateSettingsValidationIT.java
+++ b/core/src/test/java/org/elasticsearch/cluster/UpdateSettingsValidationIT.java
@@ -27,17 +27,16 @@ import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.test.ESIntegTestCase.ClusterScope;
 import org.elasticsearch.test.ESIntegTestCase.Scope;
 
-
 import static org.hamcrest.Matchers.equalTo;
 
 @ClusterScope(scope= Scope.TEST, numDataNodes =0)
 public class UpdateSettingsValidationIT extends ESIntegTestCase {
     public void testUpdateSettingsValidation() throws Exception {
-        internalCluster().startNodesAsync(
+        internalCluster().startNodes(
                 Settings.builder().put(Node.NODE_DATA_SETTING.getKey(), false).build(),
                 Settings.builder().put(Node.NODE_MASTER_SETTING.getKey(), false).build(),
                 Settings.builder().put(Node.NODE_MASTER_SETTING.getKey(), false).build()
-        ).get();
+        );
 
         createIndex("test");
         NumShards test = getNumShards("test");
diff --git a/core/src/test/java/org/elasticsearch/cluster/allocation/AwarenessAllocationIT.java b/core/src/test/java/org/elasticsearch/cluster/allocation/AwarenessAllocationIT.java
index 19657b0548..b814716cb4 100644
--- a/core/src/test/java/org/elasticsearch/cluster/allocation/AwarenessAllocationIT.java
+++ b/core/src/test/java/org/elasticsearch/cluster/allocation/AwarenessAllocationIT.java
@@ -57,7 +57,7 @@ public class AwarenessAllocationIT extends ESIntegTestCase {
 
 
         logger.info("--> starting 2 nodes on the same rack");
-        internalCluster().startNodesAsync(2, Settings.builder().put(commonSettings).put("node.attr.rack_id", "rack_1").build()).get();
+        internalCluster().startNodes(2, Settings.builder().put(commonSettings).put("node.attr.rack_id", "rack_1").build());
 
         createIndex("test1");
         createIndex("test2");
@@ -107,12 +107,12 @@ public class AwarenessAllocationIT extends ESIntegTestCase {
                 .build();
 
         logger.info("--> starting 4 nodes on different zones");
-        List<String> nodes = internalCluster().startNodesAsync(
+        List<String> nodes = internalCluster().startNodes(
                 Settings.builder().put(commonSettings).put("node.attr.zone", "a").build(),
                 Settings.builder().put(commonSettings).put("node.attr.zone", "b").build(),
                 Settings.builder().put(commonSettings).put("node.attr.zone", "b").build(),
                 Settings.builder().put(commonSettings).put("node.attr.zone", "a").build()
-        ).get();
+        );
         String A_0 = nodes.get(0);
         String B_0 = nodes.get(1);
         String B_1 = nodes.get(2);
@@ -153,10 +153,10 @@ public class AwarenessAllocationIT extends ESIntegTestCase {
                 .build();
 
         logger.info("--> starting 2 nodes on zones 'a' & 'b'");
-        List<String> nodes = internalCluster().startNodesAsync(
+        List<String> nodes = internalCluster().startNodes(
                 Settings.builder().put(commonSettings).put("node.attr.zone", "a").build(),
                 Settings.builder().put(commonSettings).put("node.attr.zone", "b").build()
-        ).get();
+        );
         String A_0 = nodes.get(0);
         String B_0 = nodes.get(1);
         client().admin().indices().prepareCreate("test")
diff --git a/core/src/test/java/org/elasticsearch/cluster/allocation/ClusterRerouteIT.java b/core/src/test/java/org/elasticsearch/cluster/allocation/ClusterRerouteIT.java
index 9c6a4273a7..f9f4a136e1 100644
--- a/core/src/test/java/org/elasticsearch/cluster/allocation/ClusterRerouteIT.java
+++ b/core/src/test/java/org/elasticsearch/cluster/allocation/ClusterRerouteIT.java
@@ -85,7 +85,7 @@ public class ClusterRerouteIT extends ESIntegTestCase {
     }
 
     private void rerouteWithCommands(Settings commonSettings) throws Exception {
-        List<String> nodesIds = internalCluster().startNodesAsync(2, commonSettings).get();
+        List<String> nodesIds = internalCluster().startNodes(2, commonSettings);
         final String node_1 = nodesIds.get(0);
         final String node_2 = nodesIds.get(1);
 
@@ -304,7 +304,7 @@ public class ClusterRerouteIT extends ESIntegTestCase {
     }
 
     public void testClusterRerouteWithBlocks() throws Exception {
-        List<String> nodesIds = internalCluster().startNodesAsync(2).get();
+        List<String> nodesIds = internalCluster().startNodes(2);
 
         logger.info("--> create an index with 1 shard and 0 replicas");
         assertAcked(prepareCreate("test-blocks").setSettings(Settings.builder().put("index.number_of_shards", 1).put("index.number_of_replicas", 0)));
diff --git a/core/src/test/java/org/elasticsearch/cluster/allocation/FilteringAllocationIT.java b/core/src/test/java/org/elasticsearch/cluster/allocation/FilteringAllocationIT.java
index 627fc03701..03866269ca 100644
--- a/core/src/test/java/org/elasticsearch/cluster/allocation/FilteringAllocationIT.java
+++ b/core/src/test/java/org/elasticsearch/cluster/allocation/FilteringAllocationIT.java
@@ -43,7 +43,7 @@ public class FilteringAllocationIT extends ESIntegTestCase {
 
     public void testDecommissionNodeNoReplicas() throws Exception {
         logger.info("--> starting 2 nodes");
-        List<String> nodesIds = internalCluster().startNodesAsync(2).get();
+        List<String> nodesIds = internalCluster().startNodes(2);
         final String node_0 = nodesIds.get(0);
         final String node_1 = nodesIds.get(1);
         assertThat(cluster().size(), equalTo(2));
@@ -82,7 +82,7 @@ public class FilteringAllocationIT extends ESIntegTestCase {
 
     public void testDisablingAllocationFiltering() throws Exception {
         logger.info("--> starting 2 nodes");
-        List<String> nodesIds = internalCluster().startNodesAsync(2).get();
+        List<String> nodesIds = internalCluster().startNodes(2);
         final String node_0 = nodesIds.get(0);
         final String node_1 = nodesIds.get(1);
         assertThat(cluster().size(), equalTo(2));
diff --git a/core/src/test/java/org/elasticsearch/cluster/routing/DelayedAllocationIT.java b/core/src/test/java/org/elasticsearch/cluster/routing/DelayedAllocationIT.java
index e432121898..853f0f6561 100644
--- a/core/src/test/java/org/elasticsearch/cluster/routing/DelayedAllocationIT.java
+++ b/core/src/test/java/org/elasticsearch/cluster/routing/DelayedAllocationIT.java
@@ -26,7 +26,6 @@ import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.test.ESIntegTestCase;
 import org.elasticsearch.test.InternalTestCluster;
-import org.elasticsearch.test.junit.annotations.TestLogging;
 
 import java.util.Collections;
 import java.util.List;
@@ -42,7 +41,7 @@ public class DelayedAllocationIT extends ESIntegTestCase {
      * get allocated to a free node when the node hosting it leaves the cluster.
      */
     public void testNoDelayedTimeout() throws Exception {
-        internalCluster().startNodesAsync(3).get();
+        internalCluster().startNodes(3);
         prepareCreate("test").setSettings(Settings.builder()
                 .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
                 .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 1)
@@ -61,7 +60,7 @@ public class DelayedAllocationIT extends ESIntegTestCase {
      * on it before.
      */
     public void testDelayedAllocationNodeLeavesAndComesBack() throws Exception {
-        internalCluster().startNodesAsync(3).get();
+        internalCluster().startNodes(3);
         prepareCreate("test").setSettings(Settings.builder()
                 .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
                 .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 1)
@@ -85,7 +84,7 @@ public class DelayedAllocationIT extends ESIntegTestCase {
      * though the node hosting the shard is not coming back.
      */
     public void testDelayedAllocationTimesOut() throws Exception {
-        internalCluster().startNodesAsync(3).get();
+        internalCluster().startNodes(3);
         prepareCreate("test").setSettings(Settings.builder()
                 .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
                 .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 1)
@@ -107,7 +106,7 @@ public class DelayedAllocationIT extends ESIntegTestCase {
      * even though the node it was hosted on will not come back.
      */
     public void testDelayedAllocationChangeWithSettingTo100ms() throws Exception {
-        internalCluster().startNodesAsync(3).get();
+        internalCluster().startNodes(3);
         prepareCreate("test").setSettings(Settings.builder()
                 .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
                 .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 1)
@@ -133,7 +132,7 @@ public class DelayedAllocationIT extends ESIntegTestCase {
      * even though the node it was hosted on will not come back.
      */
     public void testDelayedAllocationChangeWithSettingTo0() throws Exception {
-        internalCluster().startNodesAsync(3).get();
+        internalCluster().startNodes(3);
         prepareCreate("test").setSettings(Settings.builder()
                 .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
                 .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 1)
diff --git a/core/src/test/java/org/elasticsearch/cluster/routing/PrimaryAllocationIT.java b/core/src/test/java/org/elasticsearch/cluster/routing/PrimaryAllocationIT.java
index 93326e54db..86dd2dfe18 100644
--- a/core/src/test/java/org/elasticsearch/cluster/routing/PrimaryAllocationIT.java
+++ b/core/src/test/java/org/elasticsearch/cluster/routing/PrimaryAllocationIT.java
@@ -71,7 +71,7 @@ public class PrimaryAllocationIT extends ESIntegTestCase {
     private void createStaleReplicaScenario() throws Exception {
         logger.info("--> starting 3 nodes, 1 master, 2 data");
         String master = internalCluster().startMasterOnlyNode(Settings.EMPTY);
-        internalCluster().startDataOnlyNodesAsync(2).get();
+        internalCluster().startDataOnlyNodes(2);
 
         assertAcked(client().admin().indices().prepareCreate("test").setSettings(Settings.builder()
             .put("index.number_of_shards", 1).put("index.number_of_replicas", 1)).get());
@@ -267,7 +267,7 @@ public class PrimaryAllocationIT extends ESIntegTestCase {
 
     public void testNotWaitForQuorumCopies() throws Exception {
         logger.info("--> starting 3 nodes");
-        internalCluster().startNodesAsync(3).get();
+        internalCluster().startNodes(3);
         logger.info("--> creating index with 1 primary and 2 replicas");
         assertAcked(client().admin().indices().prepareCreate("test").setSettings(Settings.builder()
             .put("index.number_of_shards", randomIntBetween(1, 3)).put("index.number_of_replicas", 2)).get());
@@ -289,7 +289,7 @@ public class PrimaryAllocationIT extends ESIntegTestCase {
      */
     public void testForceAllocatePrimaryOnNoDecision() throws Exception {
         logger.info("--> starting 1 node");
-        final String node = internalCluster().startNodeAsync().get();
+        final String node = internalCluster().startNode();
         logger.info("--> creating index with 1 primary and 0 replicas");
         final String indexName = "test-idx";
         assertAcked(client().admin().indices()
diff --git a/core/src/test/java/org/elasticsearch/cluster/routing/allocation/decider/MockDiskUsagesIT.java b/core/src/test/java/org/elasticsearch/cluster/routing/allocation/decider/MockDiskUsagesIT.java
index 68e8fc9c94..51ddc0f3fd 100644
--- a/core/src/test/java/org/elasticsearch/cluster/routing/allocation/decider/MockDiskUsagesIT.java
+++ b/core/src/test/java/org/elasticsearch/cluster/routing/allocation/decider/MockDiskUsagesIT.java
@@ -54,7 +54,7 @@ public class MockDiskUsagesIT extends ESIntegTestCase {
     }
 
     public void testRerouteOccursOnDiskPassingHighWatermark() throws Exception {
-        List<String> nodes = internalCluster().startNodesAsync(3).get();
+        List<String> nodes = internalCluster().startNodes(3);
 
         // Wait for all 3 nodes to be up
         assertBusy(new Runnable() {
diff --git a/core/src/test/java/org/elasticsearch/discovery/DiscoveryWithServiceDisruptionsIT.java b/core/src/test/java/org/elasticsearch/discovery/DiscoveryWithServiceDisruptionsIT.java
index c5fa05d663..99a7f04e74 100644
--- a/core/src/test/java/org/elasticsearch/discovery/DiscoveryWithServiceDisruptionsIT.java
+++ b/core/src/test/java/org/elasticsearch/discovery/DiscoveryWithServiceDisruptionsIT.java
@@ -43,8 +43,8 @@ import org.elasticsearch.cluster.routing.ShardRouting;
 import org.elasticsearch.cluster.routing.ShardRoutingState;
 import org.elasticsearch.cluster.routing.allocation.command.MoveAllocationCommand;
 import org.elasticsearch.cluster.service.ClusterService;
-import org.elasticsearch.cluster.service.ClusterStateStatus;
 import org.elasticsearch.cluster.service.ClusterServiceState;
+import org.elasticsearch.cluster.service.ClusterStateStatus;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.Priority;
 import org.elasticsearch.common.Strings;
@@ -187,13 +187,13 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
     }
 
     private List<String> startCluster(int numberOfNodes, int minimumMasterNode, @Nullable int[] unicastHostsOrdinals) throws
-            ExecutionException, InterruptedException {
+        ExecutionException, InterruptedException {
         configureCluster(numberOfNodes, unicastHostsOrdinals, minimumMasterNode);
-        List<String> nodes = internalCluster().startNodesAsync(numberOfNodes).get();
+        List<String> nodes = internalCluster().startNodes(numberOfNodes);
         ensureStableCluster(numberOfNodes);
 
         // TODO: this is a temporary solution so that nodes will not base their reaction to a partition based on previous successful results
-        ZenPing zenPing = ((TestZenDiscovery)internalCluster().getInstance(Discovery.class)).getZenPing();
+        ZenPing zenPing = ((TestZenDiscovery) internalCluster().getInstance(Discovery.class)).getZenPing();
         if (zenPing instanceof UnicastZenPing) {
             ((UnicastZenPing) zenPing).clearTemporalResponses();
         }
@@ -201,16 +201,16 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
     }
 
     static final Settings DEFAULT_SETTINGS = Settings.builder()
-            .put(FaultDetection.PING_TIMEOUT_SETTING.getKey(), "1s") // for hitting simulated network failures quickly
-            .put(FaultDetection.PING_RETRIES_SETTING.getKey(), "1") // for hitting simulated network failures quickly
-            .put("discovery.zen.join_timeout", "10s")  // still long to induce failures but to long so test won't time out
-            .put(DiscoverySettings.PUBLISH_TIMEOUT_SETTING.getKey(), "1s") // <-- for hitting simulated network failures quickly
-            .put(TcpTransport.TCP_CONNECT_TIMEOUT.getKey(), "10s") // Network delay disruption waits for the min between this
-                                                                   // value and the time of disruption and does not recover immediately
-                                                                   // when disruption is stop. We should make sure we recover faster
-                                                                   // then the default of 30s, causing ensureGreen and friends to time out
+        .put(FaultDetection.PING_TIMEOUT_SETTING.getKey(), "1s") // for hitting simulated network failures quickly
+        .put(FaultDetection.PING_RETRIES_SETTING.getKey(), "1") // for hitting simulated network failures quickly
+        .put("discovery.zen.join_timeout", "10s")  // still long to induce failures but to long so test won't time out
+        .put(DiscoverySettings.PUBLISH_TIMEOUT_SETTING.getKey(), "1s") // <-- for hitting simulated network failures quickly
+        .put(TcpTransport.TCP_CONNECT_TIMEOUT.getKey(), "10s") // Network delay disruption waits for the min between this
+        // value and the time of disruption and does not recover immediately
+        // when disruption is stop. We should make sure we recover faster
+        // then the default of 30s, causing ensureGreen and friends to time out
 
-            .build();
+        .build();
 
     @Override
     protected Collection<Class<? extends Plugin>> nodePlugins() {
@@ -237,10 +237,10 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         logger.info("---> configured unicast");
         // TODO: Rarely use default settings form some of these
         Settings nodeSettings = Settings.builder()
-                .put(settings)
-                .put(NodeEnvironment.MAX_LOCAL_STORAGE_NODES_SETTING.getKey(), numberOfNodes)
-                .put(ElectMasterService.DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.getKey(), minimumMasterNode)
-                .build();
+            .put(settings)
+            .put(NodeEnvironment.MAX_LOCAL_STORAGE_NODES_SETTING.getKey(), numberOfNodes)
+            .put(ElectMasterService.DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.getKey(), minimumMasterNode)
+            .build();
 
         if (discoveryConfig == null) {
             if (unicastHostsOrdinals == null) {
@@ -306,8 +306,8 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
 
         logger.info("--> reducing min master nodes to 2");
         assertAcked(client().admin().cluster().prepareUpdateSettings()
-                .setTransientSettings(Settings.builder().put(ElectMasterService.DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.getKey(), 2))
-                .get());
+            .setTransientSettings(Settings.builder().put(ElectMasterService.DISCOVERY_ZEN_MINIMUM_MASTER_NODES_SETTING.getKey(), 2))
+            .get());
 
         String master = internalCluster().getMasterName();
         String nonMaster = null;
@@ -334,8 +334,8 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
 
         // Makes sure that the get request can be executed on each node locally:
         assertAcked(prepareCreate("test").setSettings(Settings.builder()
-                .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
-                .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 2)
+            .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
+            .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 2)
         ));
 
         // Everything is stable now, it is now time to simulate evil...
@@ -376,7 +376,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
             }
             if (!success) {
                 fail("node [" + node + "] has no master or has blocks, despite of being on the right side of the partition. State dump:\n"
-                        + nodeState);
+                    + nodeState);
             }
         }
 
@@ -388,8 +388,8 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
 
         logger.info("Verify no master block with {} set to {}", DiscoverySettings.NO_MASTER_BLOCK_SETTING.getKey(), "all");
         client().admin().cluster().prepareUpdateSettings()
-                .setTransientSettings(Settings.builder().put(DiscoverySettings.NO_MASTER_BLOCK_SETTING.getKey(), "all"))
-                .get();
+            .setTransientSettings(Settings.builder().put(DiscoverySettings.NO_MASTER_BLOCK_SETTING.getKey(), "all"))
+            .get();
 
         networkDisruption.startDisrupting();
 
@@ -416,10 +416,10 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         final List<String> nodes = startCluster(3);
 
         assertAcked(prepareCreate("test")
-                .setSettings(Settings.builder()
-                        .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1 + randomInt(2))
-                        .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, randomInt(2))
-                ));
+            .setSettings(Settings.builder()
+                .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1 + randomInt(2))
+                .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, randomInt(2))
+            ));
 
         ensureGreen();
         String isolatedNode = internalCluster().getMasterName();
@@ -440,7 +440,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
 
         for (String node : nodes) {
             ensureStableCluster(3, new TimeValue(DISRUPTION_HEALING_OVERHEAD.millis() + networkDisruption.expectedTimeToHeal().millis()),
-                    true, node);
+                true, node);
         }
 
         logger.info("issue a reroute");
@@ -468,8 +468,8 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
                 }
             } catch (AssertionError t) {
                 fail("failed comparing cluster state: " + t.getMessage() + "\n" +
-                        "--- cluster state of node [" + nodes.get(0) + "]: ---\n" + state +
-                        "\n--- cluster state [" + node + "]: ---\n" + nodeState);
+                    "--- cluster state of node [" + nodes.get(0) + "]: ---\n" + state +
+                    "\n--- cluster state [" + node + "]: ---\n" + nodeState);
             }
 
         }
@@ -482,7 +482,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
      * This test is a superset of tests run in the Jepsen test suite, with the exception of versioned updates
      */
     @TestLogging("_root:DEBUG,org.elasticsearch.action.index:TRACE,org.elasticsearch.action.get:TRACE,discovery:TRACE,org.elasticsearch.cluster.service:TRACE,"
-            + "org.elasticsearch.indices.recovery:TRACE,org.elasticsearch.indices.cluster:TRACE")
+        + "org.elasticsearch.indices.recovery:TRACE,org.elasticsearch.indices.cluster:TRACE")
     public void testAckedIndexing() throws Exception {
 
         final int seconds = !(TEST_NIGHTLY && rarely()) ? 1 : 5;
@@ -491,10 +491,10 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         final List<String> nodes = startCluster(rarely() ? 5 : 3);
 
         assertAcked(prepareCreate("test")
-                .setSettings(Settings.builder()
-                        .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1 + randomInt(2))
-                        .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, randomInt(2))
-                ));
+            .setSettings(Settings.builder()
+                .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1 + randomInt(2))
+                .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, randomInt(2))
+            ));
         ensureGreen();
 
         ServiceDisruptionScheme disruptionScheme = addRandomDisruptionScheme();
@@ -530,7 +530,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
                                 int shard = Math.floorMod(Murmur3HashFunction.hash(id), numPrimaries);
                                 logger.trace("[{}] indexing id [{}] through node [{}] targeting shard [{}]", name, id, node, shard);
                                 IndexResponse response =
-                                        client.prepareIndex("test", "type", id).setSource("{}").setTimeout(timeout).get(timeout);
+                                    client.prepareIndex("test", "type", id).setSource("{}").setTimeout(timeout).get(timeout);
                                 assertEquals(DocWriteResponse.Result.CREATED, response.getResult());
                                 ackedDocs.put(id, node);
                                 logger.trace("[{}] indexed id [{}] through node [{}]", name, id, node);
@@ -584,7 +584,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
                 disruptionScheme.stopDisrupting();
                 for (String node : internalCluster().getNodeNames()) {
                     ensureStableCluster(nodes.size(), TimeValue.timeValueMillis(disruptionScheme.expectedTimeToHeal().millis() +
-                            DISRUPTION_HEALING_OVERHEAD.millis()), true, node);
+                        DISRUPTION_HEALING_OVERHEAD.millis()), true, node);
                 }
                 ensureGreen("test");
 
@@ -594,7 +594,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
                         logger.debug("validating through node [{}] ([{}] acked docs)", node, ackedDocs.size());
                         for (String id : ackedDocs.keySet()) {
                             assertTrue("doc [" + id + "] indexed via node [" + ackedDocs.get(id) + "] not found",
-                                    client(node).prepareGet("test", "type", id).setPreference("_local").get().isExists());
+                                client(node).prepareGet("test", "type", id).setPreference("_local").get().isExists());
                         }
                     } catch (AssertionError e) {
                         throw new AssertionError(e.getMessage() + " (checked via node [" + node + "]", e);
@@ -684,7 +684,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
 
         // Keeps track of the previous and current master when a master node transition took place on each node on the majority side:
         final Map<String, List<Tuple<String, String>>> masters = Collections.synchronizedMap(new HashMap<String, List<Tuple<String,
-                String>>>());
+            String>>>());
         for (final String node : majoritySide) {
             masters.put(node, new ArrayList<Tuple<String, String>>());
             internalCluster().getInstance(ClusterService.class, node).add(new ClusterStateListener() {
@@ -694,7 +694,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
                     DiscoveryNode currentMaster = event.state().nodes().getMasterNode();
                     if (!Objects.equals(previousMaster, currentMaster)) {
                         logger.info("node {} received new cluster state: {} \n and had previous cluster state: {}", node, event.state(),
-                                event.previousState());
+                            event.previousState());
                         String previousMasterNodeName = previousMaster != null ? previousMaster.getName() : null;
                         String currentMasterNodeName = currentMaster != null ? currentMaster.getName() : null;
                         masters.get(node).add(new Tuple<>(previousMasterNodeName, currentMasterNodeName));
@@ -739,17 +739,17 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         // The old master node will send this update + the cluster state where he is flagged as master to the other
         // nodes that follow the new master. These nodes should ignore this update.
         internalCluster().getInstance(ClusterService.class, oldMasterNode).submitStateUpdateTask("sneaky-update", new
-                ClusterStateUpdateTask(Priority.IMMEDIATE) {
-            @Override
-            public ClusterState execute(ClusterState currentState) throws Exception {
-                return ClusterState.builder(currentState).build();
-            }
+            ClusterStateUpdateTask(Priority.IMMEDIATE) {
+                @Override
+                public ClusterState execute(ClusterState currentState) throws Exception {
+                    return ClusterState.builder(currentState).build();
+                }
 
-            @Override
-            public void onFailure(String source, Exception e) {
-                logger.warn((Supplier<?>) () -> new ParameterizedMessage("failure [{}]", source), e);
-            }
-        });
+                @Override
+                public void onFailure(String source, Exception e) {
+                    logger.warn((Supplier<?>) () -> new ParameterizedMessage("failure [{}]", source), e);
+                }
+            });
 
         // Save the new elected master node
         final String newMasterNode = internalCluster().getMasterName(majoritySide.get(0));
@@ -769,15 +769,15 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
             String nodeName = entry.getKey();
             List<Tuple<String, String>> recordedMasterTransition = entry.getValue();
             assertThat("[" + nodeName + "] Each node should only record two master node transitions", recordedMasterTransition.size(),
-                    equalTo(2));
+                equalTo(2));
             assertThat("[" + nodeName + "] First transition's previous master should be [null]", recordedMasterTransition.get(0).v1(),
-                    equalTo(oldMasterNode));
+                equalTo(oldMasterNode));
             assertThat("[" + nodeName + "] First transition's current master should be [" + newMasterNode + "]", recordedMasterTransition
-                    .get(0).v2(), nullValue());
+                .get(0).v2(), nullValue());
             assertThat("[" + nodeName + "] Second transition's previous master should be [null]", recordedMasterTransition.get(1).v1(),
-                    nullValue());
+                nullValue());
             assertThat("[" + nodeName + "] Second transition's current master should be [" + newMasterNode + "]",
-                    recordedMasterTransition.get(1).v2(), equalTo(newMasterNode));
+                recordedMasterTransition.get(1).v2(), equalTo(newMasterNode));
         }
     }
 
@@ -789,11 +789,11 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         List<String> nodes = startCluster(3);
 
         assertAcked(prepareCreate("test")
-                .setSettings(Settings.builder()
-                        .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
-                        .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 2)
-                )
-                .get());
+            .setSettings(Settings.builder()
+                .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
+                .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 2)
+            )
+            .get());
         ensureGreen("test");
 
         nodes = new ArrayList<>(nodes);
@@ -809,13 +809,13 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
 
 
         IndexResponse indexResponse = internalCluster().client(notIsolatedNode).prepareIndex("test", "type").setSource("field", "value")
-                .get();
+            .get();
         assertThat(indexResponse.getVersion(), equalTo(1L));
 
         logger.info("Verifying if document exists via node[{}]", notIsolatedNode);
         GetResponse getResponse = internalCluster().client(notIsolatedNode).prepareGet("test", "type", indexResponse.getId())
-                .setPreference("_local")
-                .get();
+            .setPreference("_local")
+            .get();
         assertThat(getResponse.isExists(), is(true));
         assertThat(getResponse.getVersion(), equalTo(1L));
         assertThat(getResponse.getId(), equalTo(indexResponse.getId()));
@@ -828,8 +828,8 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         for (String node : nodes) {
             logger.info("Verifying if document exists after isolating node[{}] via node[{}]", isolatedNode, node);
             getResponse = internalCluster().client(node).prepareGet("test", "type", indexResponse.getId())
-                    .setPreference("_local")
-                    .get();
+                .setPreference("_local")
+                .get();
             assertThat(getResponse.isExists(), is(true));
             assertThat(getResponse.getVersion(), equalTo(1L));
             assertThat(getResponse.getId(), equalTo(indexResponse.getId()));
@@ -853,7 +853,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
 
         // Forcefully clean temporal response lists on all nodes. Otherwise the node in the unicast host list
         // includes all the other nodes that have pinged it and the issue doesn't manifest
-        ZenPing zenPing = ((TestZenDiscovery)internalCluster().getInstance(Discovery.class)).getZenPing();
+        ZenPing zenPing = ((TestZenDiscovery) internalCluster().getInstance(Discovery.class)).getZenPing();
         if (zenPing instanceof UnicastZenPing) {
             ((UnicastZenPing) zenPing).clearTemporalResponses();
         }
@@ -890,7 +890,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
 
         // Forcefully clean temporal response lists on all nodes. Otherwise the node in the unicast host list
         // includes all the other nodes that have pinged it and the issue doesn't manifest
-        ZenPing zenPing = ((TestZenDiscovery)internalCluster().getInstance(Discovery.class)).getZenPing();
+        ZenPing zenPing = ((TestZenDiscovery) internalCluster().getInstance(Discovery.class)).getZenPing();
         if (zenPing instanceof UnicastZenPing) {
             ((UnicastZenPing) zenPing).clearTemporalResponses();
         }
@@ -928,11 +928,11 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         DiscoveryNodes discoveryNodes = internalCluster().getInstance(ClusterService.class, nonMasterNode).state().nodes();
 
         TransportService masterTranspotService =
-                internalCluster().getInstance(TransportService.class, discoveryNodes.getMasterNode().getName());
+            internalCluster().getInstance(TransportService.class, discoveryNodes.getMasterNode().getName());
 
         logger.info("blocking requests from non master [{}] to master [{}]", nonMasterNode, masterNode);
         MockTransportService nonMasterTransportService = (MockTransportService) internalCluster().getInstance(TransportService.class,
-                nonMasterNode);
+            nonMasterNode);
         nonMasterTransportService.addFailToSendNoConnectRule(masterTranspotService);
 
         assertNoMaster(nonMasterNode);
@@ -951,10 +951,10 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         logger.info("allowing requests from non master [{}] to master [{}], waiting for two join request", nonMasterNode, masterNode);
         final CountDownLatch countDownLatch = new CountDownLatch(2);
         nonMasterTransportService.addDelegate(masterTranspotService, new MockTransportService.DelegateTransport(nonMasterTransportService
-                .original()) {
+            .original()) {
             @Override
             public void sendRequest(DiscoveryNode node, long requestId, String action, TransportRequest request, TransportRequestOptions
-                    options) throws IOException, TransportException {
+                options) throws IOException, TransportException {
                 if (action.equals(MembershipAction.DISCOVERY_JOIN_ACTION_NAME)) {
                     countDownLatch.countDown();
                 }
@@ -982,16 +982,16 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         List<String> nonMasterNodes = nodes.stream().filter(node -> !node.equals(masterNode)).collect(Collectors.toList());
         String nonMasterNode = randomFrom(nonMasterNodes);
         assertAcked(prepareCreate("test")
-                .setSettings(Settings.builder()
-                        .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 3)
-                        .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 2)
-                ));
+            .setSettings(Settings.builder()
+                .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 3)
+                .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 2)
+            ));
         ensureGreen();
         String nonMasterNodeId = internalCluster().clusterService(nonMasterNode).localNode().getId();
 
         // fail a random shard
         ShardRouting failedShard =
-                randomFrom(clusterService().state().getRoutingNodes().node(nonMasterNodeId).shardsWithState(ShardRoutingState.STARTED));
+            randomFrom(clusterService().state().getRoutingNodes().node(nonMasterNodeId).shardsWithState(ShardRoutingState.STARTED));
         ShardStateAction service = internalCluster().getInstance(ShardStateAction.class, nonMasterNode);
         CountDownLatch latch = new CountDownLatch(1);
         AtomicBoolean success = new AtomicBoolean();
@@ -1006,20 +1006,20 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         networkDisruption.startDisrupting();
 
         service.localShardFailed(failedShard, "simulated", new CorruptIndexException("simulated", (String) null), new
-                ShardStateAction.Listener() {
-            @Override
-            public void onSuccess() {
-                success.set(true);
-                latch.countDown();
-            }
+            ShardStateAction.Listener() {
+                @Override
+                public void onSuccess() {
+                    success.set(true);
+                    latch.countDown();
+                }
 
-            @Override
-            public void onFailure(Exception e) {
-                success.set(false);
-                latch.countDown();
-                assert false;
-            }
-        });
+                @Override
+                public void onFailure(Exception e) {
+                    success.set(false);
+                    latch.countDown();
+                    assert false;
+                }
+            });
 
         if (isolatedNode.equals(nonMasterNode)) {
             assertNoMaster(nonMasterNode);
@@ -1051,11 +1051,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         SlowClusterStateProcessing disruption = new SlowClusterStateProcessing(random(), 0, 0, 1000, 2000);
 
         // don't wait for initial state, wat want to add the disruption while the cluster is forming..
-        internalCluster().startNodesAsync(3,
-                Settings.builder()
-                        .put(DiscoverySettings.INITIAL_STATE_TIMEOUT_SETTING.getKey(), "1ms")
-                        .put(DiscoverySettings.PUBLISH_TIMEOUT_SETTING.getKey(), "3s")
-                        .build()).get();
+        internalCluster().startNodes(3, Settings.builder().put(DiscoverySettings.PUBLISH_TIMEOUT_SETTING.getKey(), "3s").build());
 
         logger.info("applying disruption while cluster is forming ...");
 
@@ -1084,7 +1080,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
 
         logger.info("blocking request from master [{}] to [{}]", masterNode, nonMasterNode);
         MockTransportService masterTransportService = (MockTransportService) internalCluster().getInstance(TransportService.class,
-                masterNode);
+            masterNode);
         if (randomBoolean()) {
             masterTransportService.addUnresponsiveRule(internalCluster().getInstance(TransportService.class, nonMasterNode));
         } else {
@@ -1110,21 +1106,18 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
     public void testSearchWithRelocationAndSlowClusterStateProcessing() throws Exception {
         // don't use DEFAULT settings (which can cause node disconnects on a slow CI machine)
         configureCluster(Settings.EMPTY, 3, null, 1);
-        InternalTestCluster.Async<String> masterNodeFuture = internalCluster().startMasterOnlyNodeAsync();
-        InternalTestCluster.Async<String> node_1Future = internalCluster().startDataOnlyNodeAsync();
+        final String masterNode = internalCluster().startMasterOnlyNode();
+        final String node_1 = internalCluster().startDataOnlyNode();
 
-        final String node_1 = node_1Future.get();
-        final String masterNode = masterNodeFuture.get();
         logger.info("--> creating index [test] with one shard and on replica");
         assertAcked(prepareCreate("test").setSettings(
-                Settings.builder().put(indexSettings())
-                        .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
-                        .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 0))
+            Settings.builder().put(indexSettings())
+                .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
+                .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 0))
         );
         ensureGreen("test");
 
-        InternalTestCluster.Async<String> node_2Future = internalCluster().startDataOnlyNodeAsync();
-        final String node_2 = node_2Future.get();
+        final String node_2 = internalCluster().startDataOnlyNode();
         List<IndexRequestBuilder> indexRequestBuilderList = new ArrayList<>();
         for (int i = 0; i < 100; i++) {
             indexRequestBuilderList.add(client().prepareIndex().setIndex("test").setType("doc").setSource("{\"int_field\":1}"));
@@ -1137,7 +1130,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         CountDownLatch beginRelocationLatch = new CountDownLatch(1);
         CountDownLatch endRelocationLatch = new CountDownLatch(1);
         transportServiceNode2.addTracer(new IndicesStoreIntegrationIT.ReclocationStartEndTracer(logger, beginRelocationLatch,
-                endRelocationLatch));
+            endRelocationLatch));
         internalCluster().client().admin().cluster().prepareReroute().add(new MoveAllocationCommand("test", 0, node_1, node_2)).get();
         // wait for relocation to start
         beginRelocationLatch.await();
@@ -1176,21 +1169,19 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
      */
     public void testIndicesDeleted() throws Exception {
         final Settings settings = Settings.builder()
-                                      .put(DEFAULT_SETTINGS)
-                                      .put(DiscoverySettings.PUBLISH_TIMEOUT_SETTING.getKey(), "0s") // don't wait on isolated data node
-                                      .put(DiscoverySettings.COMMIT_TIMEOUT_SETTING.getKey(), "30s") // wait till cluster state is committed
-                                      .build();
+            .put(DEFAULT_SETTINGS)
+            .put(DiscoverySettings.PUBLISH_TIMEOUT_SETTING.getKey(), "0s") // don't wait on isolated data node
+            .put(DiscoverySettings.COMMIT_TIMEOUT_SETTING.getKey(), "30s") // wait till cluster state is committed
+            .build();
         final String idxName = "test";
         configureCluster(settings, 3, null, 2);
-        InternalTestCluster.Async<List<String>> masterNodes = internalCluster().startMasterOnlyNodesAsync(2);
-        InternalTestCluster.Async<String> dataNode = internalCluster().startDataOnlyNodeAsync();
-        dataNode.get();
-        final List<String> allMasterEligibleNodes = masterNodes.get();
+        final List<String> allMasterEligibleNodes = internalCluster().startMasterOnlyNodes(2);
+        final String dataNode = internalCluster().startDataOnlyNode();
         ensureStableCluster(3);
         assertAcked(prepareCreate("test"));
 
         final String masterNode1 = internalCluster().getMasterName();
-        NetworkDisruption networkDisruption = new NetworkDisruption(new TwoPartitions(masterNode1, dataNode.get()),
+        NetworkDisruption networkDisruption = new NetworkDisruption(new TwoPartitions(masterNode1, dataNode),
             new NetworkUnresponsive());
         internalCluster().setDisruptionScheme(networkDisruption);
         networkDisruption.startDisrupting();
@@ -1202,7 +1193,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
             for (String masterNode : allMasterEligibleNodes) {
                 final ClusterServiceState masterState = internalCluster().clusterService(masterNode).clusterServiceState();
                 assertTrue("index not deleted on " + masterNode, masterState.getClusterState().metaData().hasIndex(idxName) == false &&
-                                                                 masterState.getClusterStateStatus() == ClusterStateStatus.APPLIED);
+                    masterState.getClusterStateStatus() == ClusterStateStatus.APPLIED);
             }
         });
         internalCluster().restartNode(masterNode1, InternalTestCluster.EMPTY_CALLBACK);
@@ -1212,21 +1203,21 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
 
     public void testElectMasterWithLatestVersion() throws Exception {
         configureCluster(3, null, 2);
-        final Set<String> nodes = new HashSet<>(internalCluster().startNodesAsync(3).get());
+        final Set<String> nodes = new HashSet<>(internalCluster().startNodes(3));
         ensureStableCluster(3);
         ServiceDisruptionScheme isolateAllNodes = new NetworkDisruption(new NetworkDisruption.IsolateAllNodes(nodes), new NetworkDisconnect());
         internalCluster().setDisruptionScheme(isolateAllNodes);
 
         logger.info("--> forcing a complete election to make sure \"preferred\" master is elected");
         isolateAllNodes.startDisrupting();
-        for (String node: nodes) {
+        for (String node : nodes) {
             assertNoMaster(node);
         }
         isolateAllNodes.stopDisrupting();
         ensureStableCluster(3);
         final String preferredMasterName = internalCluster().getMasterName();
         final DiscoveryNode preferredMaster = internalCluster().clusterService(preferredMasterName).localNode();
-        for (String node: nodes) {
+        for (String node : nodes) {
             DiscoveryNode discoveryNode = internalCluster().clusterService(node).localNode();
             assertThat(discoveryNode.getId(), greaterThanOrEqualTo(preferredMaster.getId()));
         }
@@ -1252,7 +1243,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
 
         logger.info("--> forcing a complete election again");
         isolateAllNodes.startDisrupting();
-        for (String node: nodes) {
+        for (String node : nodes) {
             assertNoMaster(node);
         }
 
@@ -1298,10 +1289,17 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
         }
         final NetworkLinkDisruptionType disruptionType;
         switch (randomInt(2)) {
-            case 0: disruptionType = new NetworkUnresponsive(); break;
-            case 1: disruptionType = new NetworkDisconnect(); break;
-            case 2: disruptionType = NetworkDelay.random(random()); break;
-            default: throw new IllegalArgumentException();
+            case 0:
+                disruptionType = new NetworkUnresponsive();
+                break;
+            case 1:
+                disruptionType = new NetworkDisconnect();
+                break;
+            case 2:
+                disruptionType = NetworkDelay.random(random());
+                break;
+            default:
+                throw new IllegalArgumentException();
         }
         final ServiceDisruptionScheme scheme;
         if (rarely()) {
@@ -1334,7 +1332,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
                 if (expectedBlocks != null) {
                     for (ClusterBlockLevel level : expectedBlocks.levels()) {
                         assertTrue("node [" + node + "] does have level [" + level + "] in it's blocks", state.getBlocks().hasGlobalBlock
-                                (level));
+                            (level));
                     }
                 }
             }
@@ -1352,7 +1350,7 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
                 }
                 logger.trace("[{}] master is [{}]", node, state.nodes().getMasterNode());
                 assertThat("node [" + node + "] still has [" + masterNode + "] as master",
-                        oldMasterNode, not(equalTo(masterNode)));
+                    oldMasterNode, not(equalTo(masterNode)));
             }
         }, 10, TimeUnit.SECONDS);
     }
@@ -1372,12 +1370,12 @@ public class DiscoveryWithServiceDisruptionsIT extends ESIntegTestCase {
     private void assertDiscoveryCompleted(List<String> nodes) throws InterruptedException {
         for (final String node : nodes) {
             assertTrue(
-                    "node [" + node + "] is still joining master",
-                    awaitBusy(
-                            () -> !((ZenDiscovery) internalCluster().getInstance(Discovery.class, node)).joiningCluster(),
-                            30,
-                            TimeUnit.SECONDS
-                    )
+                "node [" + node + "] is still joining master",
+                awaitBusy(
+                    () -> !((ZenDiscovery) internalCluster().getInstance(Discovery.class, node)).joiningCluster(),
+                    30,
+                    TimeUnit.SECONDS
+                )
             );
         }
     }
diff --git a/core/src/test/java/org/elasticsearch/discovery/ZenUnicastDiscoveryIT.java b/core/src/test/java/org/elasticsearch/discovery/ZenUnicastDiscoveryIT.java
deleted file mode 100644
index b708ab4c26..0000000000
--- a/core/src/test/java/org/elasticsearch/discovery/ZenUnicastDiscoveryIT.java
+++ /dev/null
@@ -1,102 +0,0 @@
-/*
- * Licensed to Elasticsearch under one or more contributor
- * license agreements. See the NOTICE file distributed with
- * this work for additional information regarding copyright
- * ownership. Elasticsearch licenses this file to you under
- * the Apache License, Version 2.0 (the "License"); you may
- * not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *    http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied.  See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-
-package org.elasticsearch.discovery;
-
-import org.elasticsearch.cluster.ClusterState;
-import org.elasticsearch.cluster.node.DiscoveryNode;
-import org.elasticsearch.common.settings.Settings;
-import org.elasticsearch.common.unit.TimeValue;
-import org.elasticsearch.test.ESIntegTestCase;
-import org.elasticsearch.test.ESIntegTestCase.ClusterScope;
-import org.elasticsearch.test.ESIntegTestCase.Scope;
-import org.elasticsearch.test.discovery.ClusterDiscoveryConfiguration;
-import org.junit.Before;
-
-import java.util.List;
-import java.util.concurrent.ExecutionException;
-
-import static org.hamcrest.Matchers.equalTo;
-
-@ClusterScope(scope = Scope.TEST, numDataNodes = 0, autoMinMasterNodes = false)
-public class ZenUnicastDiscoveryIT extends ESIntegTestCase {
-
-    private ClusterDiscoveryConfiguration discoveryConfig;
-
-    @Override
-    protected Settings nodeSettings(int nodeOrdinal) {
-        return discoveryConfig.nodeSettings(nodeOrdinal);
-    }
-
-    @Before
-    public void clearConfig() {
-        discoveryConfig = null;
-    }
-
-    public void testNormalClusterForming() throws ExecutionException, InterruptedException {
-        int currentNumNodes = randomIntBetween(3, 5);
-
-        // use explicit unicast hosts so we can start those first
-        int[] unicastHostOrdinals = new int[randomIntBetween(1, currentNumNodes)];
-        for (int i = 0; i < unicastHostOrdinals.length; i++) {
-            unicastHostOrdinals[i] = i;
-        }
-        discoveryConfig = new ClusterDiscoveryConfiguration.UnicastZen(currentNumNodes, unicastHostOrdinals);
-
-        // start the unicast hosts
-        internalCluster().startNodesAsync(unicastHostOrdinals.length).get();
-
-        // start the rest of the cluster
-        internalCluster().startNodesAsync(currentNumNodes - unicastHostOrdinals.length).get();
-
-        if (client().admin().cluster().prepareHealth().setWaitForNodes("" + currentNumNodes).get().isTimedOut()) {
-            logger.info("cluster forming timed out, cluster state:\n{}", client().admin().cluster().prepareState().get().getState());
-            fail("timed out waiting for cluster to form with [" + currentNumNodes + "] nodes");
-        }
-    }
-
-    // Without the 'include temporalResponses responses to nodesToConnect' improvement in UnicastZenPing#sendPings this
-    // test fails, because 2 nodes elect themselves as master and the health request times out b/c waiting_for_nodes=N
-    // can't be satisfied.
-    public void testMinimumMasterNodes() throws Exception {
-        int currentNumNodes = randomIntBetween(3, 5);
-        final int min_master_nodes = currentNumNodes / 2 + 1;
-        int currentNumOfUnicastHosts = randomIntBetween(min_master_nodes, currentNumNodes);
-        final Settings settings = Settings.builder()
-                .put("discovery.zen.join_timeout", TimeValue.timeValueSeconds(10))
-                .put("discovery.zen.minimum_master_nodes", min_master_nodes)
-                .build();
-        discoveryConfig = new ClusterDiscoveryConfiguration.UnicastZen(currentNumNodes, currentNumOfUnicastHosts, settings);
-
-        List<String> nodes = internalCluster().startNodesAsync(currentNumNodes).get();
-
-        ensureStableCluster(currentNumNodes);
-
-        DiscoveryNode masterDiscoNode = null;
-        for (String node : nodes) {
-            ClusterState state = internalCluster().client(node).admin().cluster().prepareState().setLocal(true).execute().actionGet().getState();
-            assertThat(state.nodes().getSize(), equalTo(currentNumNodes));
-            if (masterDiscoNode == null) {
-                masterDiscoNode = state.nodes().getMasterNode();
-            } else {
-                assertThat(masterDiscoNode.equals(state.nodes().getMasterNode()), equalTo(true));
-            }
-        }
-    }
-}
diff --git a/core/src/test/java/org/elasticsearch/discovery/zen/ZenDiscoveryIT.java b/core/src/test/java/org/elasticsearch/discovery/zen/ZenDiscoveryIT.java
index 6856d05365..27fb48f764 100644
--- a/core/src/test/java/org/elasticsearch/discovery/zen/ZenDiscoveryIT.java
+++ b/core/src/test/java/org/elasticsearch/discovery/zen/ZenDiscoveryIT.java
@@ -80,12 +80,12 @@ public class ZenDiscoveryIT extends ESIntegTestCase {
                 .put(Node.NODE_DATA_SETTING.getKey(), false)
                 .put(defaultSettings)
                 .build();
-        internalCluster().startNodesAsync(2, masterNodeSettings).get();
+        internalCluster().startNodes(2, masterNodeSettings);
         Settings dateNodeSettings = Settings.builder()
                 .put(Node.NODE_MASTER_SETTING.getKey(), false)
                 .put(defaultSettings)
                 .build();
-        internalCluster().startNodesAsync(2, dateNodeSettings).get();
+        internalCluster().startNodes(2, dateNodeSettings);
         ClusterHealthResponse clusterHealthResponse = client().admin().cluster().prepareHealth()
                 .setWaitForEvents(Priority.LANGUID)
                 .setWaitForNodes("4")
@@ -100,13 +100,10 @@ public class ZenDiscoveryIT extends ESIntegTestCase {
 
         final String oldMaster = internalCluster().getMasterName();
         internalCluster().stopCurrentMasterNode();
-        assertBusy(new Runnable() {
-            @Override
-            public void run() {
-                String current = internalCluster().getMasterName();
-                assertThat(current, notNullValue());
-                assertThat(current, not(equalTo(oldMaster)));
-            }
+        assertBusy(() -> {
+            String current = internalCluster().getMasterName();
+            assertThat(current, notNullValue());
+            assertThat(current, not(equalTo(oldMaster)));
         });
         ensureSearchable("test");
 
@@ -130,7 +127,7 @@ public class ZenDiscoveryIT extends ESIntegTestCase {
                 .put(Node.NODE_MASTER_SETTING.getKey(), false)
                 .put(defaultSettings)
                 .build();
-        internalCluster().startNodesAsync(2, dateNodeSettings).get();
+        internalCluster().startNodes(2, dateNodeSettings);
         client().admin().cluster().prepareHealth().setWaitForNodes("3").get();
 
         ClusterService clusterService = internalCluster().getInstance(ClusterService.class, master);
@@ -155,8 +152,7 @@ public class ZenDiscoveryIT extends ESIntegTestCase {
     }
 
     public void testNodeRejectsClusterStateWithWrongMasterNode() throws Exception {
-        List<String> nodeNames = internalCluster().startNodesAsync(2).get();
-        client().admin().cluster().prepareHealth().setWaitForNodes("2").get();
+        List<String> nodeNames = internalCluster().startNodes(2);
 
         List<String> nonMasterNodes = new ArrayList<>(nodeNames);
         nonMasterNodes.remove(internalCluster().getMasterName());
diff --git a/core/src/test/java/org/elasticsearch/gateway/GatewayIndexStateIT.java b/core/src/test/java/org/elasticsearch/gateway/GatewayIndexStateIT.java
index bed21193ac..22f06b9098 100644
--- a/core/src/test/java/org/elasticsearch/gateway/GatewayIndexStateIT.java
+++ b/core/src/test/java/org/elasticsearch/gateway/GatewayIndexStateIT.java
@@ -94,7 +94,7 @@ public class GatewayIndexStateIT extends ESIntegTestCase {
 
     public void testSimpleOpenClose() throws Exception {
         logger.info("--> starting 2 nodes");
-        internalCluster().startNodesAsync(2).get();
+        internalCluster().startNodes(2);
 
         logger.info("--> creating test index");
         createIndex("test");
@@ -237,7 +237,7 @@ public class GatewayIndexStateIT extends ESIntegTestCase {
         logger.info("--> cleaning nodes");
 
         logger.info("--> starting 2 nodes");
-        internalCluster().startNodesAsync(2).get();
+        internalCluster().startNodes(2);
 
         logger.info("--> indexing a simple document");
         client().prepareIndex("test", "type1", "1").setSource("field1", "value1").setRefreshPolicy(IMMEDIATE).get();
@@ -277,7 +277,7 @@ public class GatewayIndexStateIT extends ESIntegTestCase {
     public void testDanglingIndices() throws Exception {
         logger.info("--> starting two nodes");
 
-        final String node_1 = internalCluster().startNodesAsync(2).get().get(0);
+        final String node_1 = internalCluster().startNodes(2).get(0);
 
         logger.info("--> indexing a simple document");
         client().prepareIndex("test", "type1", "1").setSource("field1", "value1").setRefreshPolicy(IMMEDIATE).get();
@@ -331,7 +331,7 @@ public class GatewayIndexStateIT extends ESIntegTestCase {
         if (randomBoolean()) {
             // test with a regular index
             logger.info("--> starting a cluster with " + numNodes + " nodes");
-            nodes = internalCluster().startNodesAsync(numNodes).get();
+            nodes = internalCluster().startNodes(numNodes);
             logger.info("--> create an index");
             createIndex(indexName);
         } else {
@@ -344,7 +344,7 @@ public class GatewayIndexStateIT extends ESIntegTestCase {
                                                   .put(Environment.PATH_SHARED_DATA_SETTING.getKey(), dataPath.toString())
                                                   .put("index.store.fs.fs_lock", randomFrom("native", "simple"))
                                                   .build();
-            nodes = internalCluster().startNodesAsync(numNodes, nodeSettings).get();
+            nodes = internalCluster().startNodes(numNodes, nodeSettings);
             logger.info("--> create a shadow replica index");
             createShadowReplicaIndex(indexName, dataPath, numNodes - 1);
         }
diff --git a/core/src/test/java/org/elasticsearch/gateway/MetaDataWriteDataNodesIT.java b/core/src/test/java/org/elasticsearch/gateway/MetaDataWriteDataNodesIT.java
index 3c2917f38e..3dfeca3053 100644
--- a/core/src/test/java/org/elasticsearch/gateway/MetaDataWriteDataNodesIT.java
+++ b/core/src/test/java/org/elasticsearch/gateway/MetaDataWriteDataNodesIT.java
@@ -36,6 +36,7 @@ import org.elasticsearch.test.InternalTestCluster.RestartCallback;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.LinkedHashMap;
+import java.util.List;
 
 import static org.elasticsearch.common.xcontent.XContentFactory.jsonBuilder;
 import static org.elasticsearch.test.hamcrest.ElasticsearchAssertions.assertAcked;
@@ -57,10 +58,9 @@ public class MetaDataWriteDataNodesIT extends ESIntegTestCase {
     public void testMetaIsRemovedIfAllShardsFromIndexRemoved() throws Exception {
         // this test checks that the index state is removed from a data only node once all shards have been allocated away from it
         String masterNode = internalCluster().startMasterOnlyNode(Settings.EMPTY);
-        InternalTestCluster.Async<String> nodeName1 = internalCluster().startDataOnlyNodeAsync();
-        InternalTestCluster.Async<String> nodeName2 = internalCluster().startDataOnlyNodeAsync();
-        String node1 = nodeName1.get();
-        String node2 = nodeName2.get();
+        List<String> nodeNames= internalCluster().startDataOnlyNodes(2);
+        String node1 = nodeNames.get(0);
+        String node2 = nodeNames.get(1);
 
         String index = "index";
         assertAcked(prepareCreate(index).setSettings(Settings.builder().put("index.number_of_replicas", 0).put(IndexMetaData.INDEX_ROUTING_INCLUDE_GROUP_SETTING.getKey() + "_name", node1)));
diff --git a/core/src/test/java/org/elasticsearch/gateway/QuorumGatewayIT.java b/core/src/test/java/org/elasticsearch/gateway/QuorumGatewayIT.java
index 8284388d2c..3abaff3295 100644
--- a/core/src/test/java/org/elasticsearch/gateway/QuorumGatewayIT.java
+++ b/core/src/test/java/org/elasticsearch/gateway/QuorumGatewayIT.java
@@ -46,8 +46,7 @@ public class QuorumGatewayIT extends ESIntegTestCase {
     public void testQuorumRecovery() throws Exception {
         logger.info("--> starting 3 nodes");
         // we are shutting down nodes - make sure we don't have 2 clusters if we test network
-        internalCluster().startNodesAsync(3).get();
-
+        internalCluster().startNodes(3);
 
         createIndex("test");
         ensureGreen();
diff --git a/core/src/test/java/org/elasticsearch/gateway/RecoveryFromGatewayIT.java b/core/src/test/java/org/elasticsearch/gateway/RecoveryFromGatewayIT.java
index 052bfc00ef..431b592fac 100644
--- a/core/src/test/java/org/elasticsearch/gateway/RecoveryFromGatewayIT.java
+++ b/core/src/test/java/org/elasticsearch/gateway/RecoveryFromGatewayIT.java
@@ -316,7 +316,7 @@ public class RecoveryFromGatewayIT extends ESIntegTestCase {
 
     public void testLatestVersionLoaded() throws Exception {
         // clean two nodes
-        internalCluster().startNodesAsync(2, Settings.builder().put("gateway.recover_after_nodes", 2).build()).get();
+        internalCluster().startNodes(2, Settings.builder().put("gateway.recover_after_nodes", 2).build());
 
         client().prepareIndex("test", "type1", "1").setSource(jsonBuilder().startObject().field("field", "value1").endObject()).execute().actionGet();
         client().admin().indices().prepareFlush().execute().actionGet();
@@ -366,7 +366,7 @@ public class RecoveryFromGatewayIT extends ESIntegTestCase {
 
         logger.info("--> starting the two nodes back");
 
-        internalCluster().startNodesAsync(2, Settings.builder().put("gateway.recover_after_nodes", 2).build()).get();
+        internalCluster().startNodes(2, Settings.builder().put("gateway.recover_after_nodes", 2).build());
 
         logger.info("--> running cluster_health (wait for the shards to startup)");
         ensureGreen();
@@ -392,7 +392,7 @@ public class RecoveryFromGatewayIT extends ESIntegTestCase {
             .put(ThrottlingAllocationDecider.CLUSTER_ROUTING_ALLOCATION_NODE_CONCURRENT_OUTGOING_RECOVERIES_SETTING.getKey(), 4)
             .put(MockFSDirectoryService.CRASH_INDEX_SETTING.getKey(), false).build();
 
-        internalCluster().startNodesAsync(4, settings).get();
+        internalCluster().startNodes(4, settings);
         // prevent any rebalance actions during the peer recovery
         // if we run into a relocation the reuse count will be 0 and this fails the test. We are testing here if
         // we reuse the files on disk after full restarts for replicas.
diff --git a/core/src/test/java/org/elasticsearch/index/IndexWithShadowReplicasIT.java b/core/src/test/java/org/elasticsearch/index/IndexWithShadowReplicasIT.java
index a335a42edb..d5a003003a 100644
--- a/core/src/test/java/org/elasticsearch/index/IndexWithShadowReplicasIT.java
+++ b/core/src/test/java/org/elasticsearch/index/IndexWithShadowReplicasIT.java
@@ -110,7 +110,7 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
 
     public void testCannotCreateWithBadPath() throws Exception {
         Settings nodeSettings = nodeSettings("/badpath");
-        internalCluster().startNodesAsync(1, nodeSettings).get();
+        internalCluster().startNodes(1, nodeSettings);
         Settings idxSettings = Settings.builder()
                 .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
                 .put(IndexMetaData.SETTING_DATA_PATH, "/etc/foo")
@@ -132,7 +132,7 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
         final Path dataPath = createTempDir();
         Settings nodeSettings = nodeSettings(dataPath);
 
-        internalCluster().startNodesAsync(3, nodeSettings).get();
+        internalCluster().startNodes(3, nodeSettings);
         Settings idxSettings = Settings.builder()
                 .put(IndexMetaData.SETTING_NUMBER_OF_SHARDS, 1)
                 .put(IndexMetaData.SETTING_NUMBER_OF_REPLICAS, 0).build();
@@ -189,7 +189,7 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
         final Path dataPath = createTempDir();
         Settings nodeSettings = nodeSettings(dataPath);
 
-        internalCluster().startNodesAsync(3, nodeSettings).get();
+        internalCluster().startNodes(3, nodeSettings);
         final String IDX = "test";
 
         Settings idxSettings = Settings.builder()
@@ -552,7 +552,7 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
 
         final int nodeCount = randomIntBetween(2, 5);
         logger.info("--> starting {} nodes", nodeCount);
-        final List<String> nodes = internalCluster().startNodesAsync(nodeCount, nodeSettings).get();
+        final List<String> nodes = internalCluster().startNodes(nodeCount, nodeSettings);
         final String IDX = "test";
         final Tuple<Integer, Integer> numPrimariesAndReplicas = randomPrimariesAndReplicas(nodeCount);
         final int numPrimaries = numPrimariesAndReplicas.v1();
@@ -605,7 +605,7 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
         Path dataPath = createTempDir();
         Settings nodeSettings = nodeSettings(dataPath);
 
-        final List<String> nodes = internalCluster().startNodesAsync(2, nodeSettings).get();
+        final List<String> nodes = internalCluster().startNodes(2, nodeSettings);
         String IDX = "test";
 
         Settings idxSettings = Settings.builder()
@@ -661,7 +661,7 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
         Path dataPath = createTempDir();
         Settings nodeSettings = nodeSettings(dataPath);
 
-        internalCluster().startNodesAsync(3, nodeSettings).get();
+        internalCluster().startNodes(3, nodeSettings);
         String IDX = "test";
 
         Settings idxSettings = Settings.builder()
@@ -731,10 +731,9 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
         Settings fooSettings = Settings.builder().put(nodeSettings).put("node.attr.affinity", "foo").build();
         Settings barSettings = Settings.builder().put(nodeSettings).put("node.attr.affinity", "bar").build();
 
-        final InternalTestCluster.Async<List<String>> fooNodes = internalCluster().startNodesAsync(2, fooSettings);
-        final InternalTestCluster.Async<List<String>> barNodes = internalCluster().startNodesAsync(2, barSettings);
-        fooNodes.get();
-        barNodes.get();
+        List<String> allNodes = internalCluster().startNodes(fooSettings, fooSettings, barSettings, barSettings);
+        List<String> fooNodes = allNodes.subList(0, 2);
+        List<String> barNodes = allNodes.subList(2, 4);
         String IDX = "test";
 
         Settings includeFoo = Settings.builder()
@@ -768,27 +767,27 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
         client().admin().indices().prepareUpdateSettings(IDX).setSettings(includeBar).get();
 
         // wait for the shards to move from "foo" nodes to "bar" nodes
-        assertNoShardsOn(fooNodes.get());
+        assertNoShardsOn(fooNodes);
 
         // put shards back on "foo"
         client().admin().indices().prepareUpdateSettings(IDX).setSettings(includeFoo).get();
 
         // wait for the shards to move from "bar" nodes to "foo" nodes
-        assertNoShardsOn(barNodes.get());
+        assertNoShardsOn(barNodes);
 
         // Stop a foo node
         logger.info("--> stopping first 'foo' node");
-        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(fooNodes.get().get(0)));
+        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(fooNodes.get(0)));
 
         // Ensure that the other foo node has all the shards now
-        assertShardCountOn(fooNodes.get().get(1), 5);
+        assertShardCountOn(fooNodes.get(1), 5);
 
         // Assert no shards on the "bar" nodes
-        assertNoShardsOn(barNodes.get());
+        assertNoShardsOn(barNodes);
 
         // Stop the second "foo" node
         logger.info("--> stopping second 'foo' node");
-        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(fooNodes.get().get(1)));
+        internalCluster().stopRandomNode(InternalTestCluster.nameFilter(fooNodes.get(1)));
 
         // The index should still be able to be allocated (on the "bar" nodes),
         // all the "foo" nodes are gone
@@ -799,7 +798,7 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
         String newFooNode = internalCluster().startNode(fooSettings);
 
         assertShardCountOn(newFooNode, 5);
-        assertNoShardsOn(barNodes.get());
+        assertNoShardsOn(barNodes);
     }
 
     public void testDeletingClosedIndexRemovesFiles() throws Exception {
@@ -808,7 +807,7 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
 
         final int numNodes = randomIntBetween(2, 5);
         logger.info("--> starting {} nodes", numNodes);
-        final List<String> nodes = internalCluster().startNodesAsync(numNodes, nodeSettings).get();
+        final List<String> nodes = internalCluster().startNodes(numNodes, nodeSettings);
         final String IDX = "test";
         final Tuple<Integer, Integer> numPrimariesAndReplicas = randomPrimariesAndReplicas(numNodes);
         final int numPrimaries = numPrimariesAndReplicas.v1();
@@ -851,7 +850,7 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
         Path dataPath = createTempDir();
         Settings nodeSettings = nodeSettings(dataPath);
 
-        internalCluster().startNodesAsync(2, nodeSettings).get();
+        internalCluster().startNodes(2, nodeSettings);
         String IDX = "test";
 
         Settings idxSettings = Settings.builder()
@@ -868,7 +867,7 @@ public class IndexWithShadowReplicasIT extends ESIntegTestCase {
         client().prepareIndex(IDX, "doc", "2").setSource("foo", "bar").get();
         flushAndRefresh(IDX);
 
-        internalCluster().startNodesAsync(1).get();
+        internalCluster().startNodes(1);
         ensureYellow(IDX);
 
         final ClusterHealthResponse clusterHealth = client().admin().cluster()
diff --git a/core/src/test/java/org/elasticsearch/index/store/CorruptedTranslogIT.java b/core/src/test/java/org/elasticsearch/index/store/CorruptedTranslogIT.java
index 7d658a2a59..1fe6be5346 100644
--- a/core/src/test/java/org/elasticsearch/index/store/CorruptedTranslogIT.java
+++ b/core/src/test/java/org/elasticsearch/index/store/CorruptedTranslogIT.java
@@ -72,7 +72,7 @@ public class CorruptedTranslogIT extends ESIntegTestCase {
     }
 
     public void testCorruptTranslogFiles() throws Exception {
-        internalCluster().startNodesAsync(1, Settings.EMPTY).get();
+        internalCluster().startNodes(1, Settings.EMPTY);
 
         assertAcked(prepareCreate("test").setSettings(Settings.builder()
                 .put("index.number_of_shards", 1)
diff --git a/core/src/test/java/org/elasticsearch/index/translog/TruncateTranslogIT.java b/core/src/test/java/org/elasticsearch/index/translog/TruncateTranslogIT.java
index ff4de23a06..bb8943f19d 100644
--- a/core/src/test/java/org/elasticsearch/index/translog/TruncateTranslogIT.java
+++ b/core/src/test/java/org/elasticsearch/index/translog/TruncateTranslogIT.java
@@ -28,7 +28,6 @@ import org.apache.lucene.store.FSDirectory;
 import org.apache.lucene.store.Lock;
 import org.apache.lucene.store.LockObtainFailedException;
 import org.apache.lucene.store.NativeFSLockFactory;
-import org.elasticsearch.ElasticsearchException;
 import org.elasticsearch.action.admin.cluster.node.stats.NodesStatsResponse;
 import org.elasticsearch.action.index.IndexRequestBuilder;
 import org.elasticsearch.action.search.SearchPhaseExecutionException;
@@ -47,7 +46,6 @@ import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.index.IndexSettings;
 import org.elasticsearch.index.MockEngineFactoryPlugin;
-import org.elasticsearch.index.translog.TruncateTranslogCommand;
 import org.elasticsearch.monitor.fs.FsInfo;
 import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.test.ESIntegTestCase;
@@ -85,7 +83,7 @@ public class TruncateTranslogIT extends ESIntegTestCase {
     }
 
     public void testCorruptTranslogTruncation() throws Exception {
-        internalCluster().startNodesAsync(1, Settings.EMPTY).get();
+        internalCluster().startNodes(1, Settings.EMPTY);
 
         assertAcked(prepareCreate("test").setSettings(Settings.builder()
                         .put("index.number_of_shards", 1)
diff --git a/core/src/test/java/org/elasticsearch/indices/mapping/DedicatedMasterGetFieldMappingIT.java b/core/src/test/java/org/elasticsearch/indices/mapping/DedicatedMasterGetFieldMappingIT.java
index 81c9d12fbb..f8fe05bc97 100644
--- a/core/src/test/java/org/elasticsearch/indices/mapping/DedicatedMasterGetFieldMappingIT.java
+++ b/core/src/test/java/org/elasticsearch/indices/mapping/DedicatedMasterGetFieldMappingIT.java
@@ -34,7 +34,7 @@ public class DedicatedMasterGetFieldMappingIT extends SimpleGetFieldMappingsIT {
         Settings settings = Settings.builder()
                 .put(Node.NODE_DATA_SETTING.getKey(), false)
                 .build();
-        internalCluster().startNodesAsync(settings, Settings.EMPTY).get();
+        internalCluster().startNodes(settings, Settings.EMPTY);
     }
 
 }
diff --git a/core/src/test/java/org/elasticsearch/indices/state/RareClusterStateIT.java b/core/src/test/java/org/elasticsearch/indices/state/RareClusterStateIT.java
index fe3b569755..c38c20e0c2 100644
--- a/core/src/test/java/org/elasticsearch/indices/state/RareClusterStateIT.java
+++ b/core/src/test/java/org/elasticsearch/indices/state/RareClusterStateIT.java
@@ -43,7 +43,6 @@ import org.elasticsearch.common.collect.ImmutableOpenMap;
 import org.elasticsearch.common.settings.Settings;
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.discovery.DiscoverySettings;
-import org.elasticsearch.discovery.zen.ElectMasterService;
 import org.elasticsearch.gateway.GatewayAllocator;
 import org.elasticsearch.index.Index;
 import org.elasticsearch.index.IndexService;
@@ -174,7 +173,7 @@ public class RareClusterStateIT extends ESIntegTestCase {
 
     @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/14932")
     public void testDeleteCreateInOneBulk() throws Exception {
-        internalCluster().startNodesAsync(2).get();
+        internalCluster().startNodes(2);
         assertFalse(client().admin().cluster().prepareHealth().setWaitForNodes("2").get().isTimedOut());
         prepareCreate("test").setSettings(IndexMetaData.SETTING_AUTO_EXPAND_REPLICAS, true).addMapping("type").get();
         ensureGreen("test");
@@ -213,7 +212,7 @@ public class RareClusterStateIT extends ESIntegTestCase {
             .put(DiscoverySettings.COMMIT_TIMEOUT_SETTING.getKey(), "30s") // explicitly set so it won't default to publish timeout
             .put(DiscoverySettings.PUBLISH_TIMEOUT_SETTING.getKey(), "0s") // don't wait post commit as we are blocking things by design
             .build();
-        final List<String> nodeNames = internalCluster().startNodesAsync(2, settings).get();
+        final List<String> nodeNames = internalCluster().startNodes(2, settings);
         assertFalse(client().admin().cluster().prepareHealth().setWaitForNodes("2").get().isTimedOut());
 
         final String master = internalCluster().getMasterName();
@@ -328,11 +327,11 @@ public class RareClusterStateIT extends ESIntegTestCase {
         // Here we want to test that everything goes well if the mappings that
         // are needed for a document are not available on the replica at the
         // time of indexing it
-        final List<String> nodeNames = internalCluster().startNodesAsync(2,
+        final List<String> nodeNames = internalCluster().startNodes(2,
             Settings.builder()
                 .put(DiscoverySettings.COMMIT_TIMEOUT_SETTING.getKey(), "30s") // explicitly set so it won't default to publish timeout
                 .put(DiscoverySettings.PUBLISH_TIMEOUT_SETTING.getKey(), "0s") // don't wait post commit as we are blocking things by design
-                .build()).get();
+                .build());
         assertFalse(client().admin().cluster().prepareHealth().setWaitForNodes("2").get().isTimedOut());
 
         final String master = internalCluster().getMasterName();
diff --git a/core/src/test/java/org/elasticsearch/indices/store/IndicesStoreIntegrationIT.java b/core/src/test/java/org/elasticsearch/indices/store/IndicesStoreIntegrationIT.java
index a6420034c4..d8e7e7c4ac 100644
--- a/core/src/test/java/org/elasticsearch/indices/store/IndicesStoreIntegrationIT.java
+++ b/core/src/test/java/org/elasticsearch/indices/store/IndicesStoreIntegrationIT.java
@@ -292,17 +292,14 @@ public class IndicesStoreIntegrationIT extends ESIntegTestCase {
     }
 
     public void testShardActiveElsewhereDoesNotDeleteAnother() throws Exception {
-        InternalTestCluster.Async<String> masterFuture = internalCluster().startNodeAsync(
-                Settings.builder().put(Node.NODE_MASTER_SETTING.getKey(), true, Node.NODE_DATA_SETTING.getKey(), false).build());
-        InternalTestCluster.Async<List<String>> nodesFutures = internalCluster().startNodesAsync(4,
-                Settings.builder().put(Node.NODE_MASTER_SETTING.getKey(), false, Node.NODE_DATA_SETTING.getKey(), true).build());
-
-        final String masterNode = masterFuture.get();
-        final String node1 = nodesFutures.get().get(0);
-        final String node2 = nodesFutures.get().get(1);
-        final String node3 = nodesFutures.get().get(2);
+        final String masterNode = internalCluster().startMasterOnlyNode();
+        final List<String> nodes = internalCluster().startDataOnlyNodes(4);
+
+        final String node1 = nodes.get(0);
+        final String node2 = nodes.get(1);
+        final String node3 = nodes.get(2);
         // we will use this later on, handy to start now to make sure it has a different data folder that node 1,2 &3
-        final String node4 = nodesFutures.get().get(3);
+        final String node4 = nodes.get(3);
 
         assertAcked(prepareCreate("test").setSettings(Settings.builder()
                         .put(indexSettings())
@@ -356,8 +353,7 @@ public class IndicesStoreIntegrationIT extends ESIntegTestCase {
 
         logger.debug("--> starting the two old nodes back");
 
-        internalCluster().startNodesAsync(2,
-                Settings.builder().put(Node.NODE_MASTER_SETTING.getKey(), false, Node.NODE_DATA_SETTING.getKey(), true).build());
+        internalCluster().startDataOnlyNodes(2);
 
         assertFalse(client().admin().cluster().prepareHealth().setWaitForNodes("5").get().isTimedOut());
 
@@ -372,7 +368,7 @@ public class IndicesStoreIntegrationIT extends ESIntegTestCase {
     }
 
     public void testShardActiveElseWhere() throws Exception {
-        List<String> nodes = internalCluster().startNodesAsync(2).get();
+        List<String> nodes = internalCluster().startNodes(2);
 
         final String masterNode = internalCluster().getMasterName();
         final String nonMasterNode = nodes.get(0).equals(masterNode) ? nodes.get(1) : nodes.get(0);
diff --git a/core/src/test/java/org/elasticsearch/nodesinfo/SimpleNodesInfoIT.java b/core/src/test/java/org/elasticsearch/nodesinfo/SimpleNodesInfoIT.java
index 2147cea696..f1dba4e58c 100644
--- a/core/src/test/java/org/elasticsearch/nodesinfo/SimpleNodesInfoIT.java
+++ b/core/src/test/java/org/elasticsearch/nodesinfo/SimpleNodesInfoIT.java
@@ -40,7 +40,7 @@ import static org.hamcrest.Matchers.notNullValue;
 public class SimpleNodesInfoIT extends ESIntegTestCase {
 
     public void testNodesInfos() throws Exception {
-        List<String> nodesIds = internalCluster().startNodesAsync(2).get();
+        List<String> nodesIds = internalCluster().startNodes(2);
         final String node_1 = nodesIds.get(0);
         final String node_2 = nodesIds.get(1);
 
@@ -79,7 +79,7 @@ public class SimpleNodesInfoIT extends ESIntegTestCase {
     }
 
     public void testNodesInfosTotalIndexingBuffer() throws Exception {
-        List<String> nodesIds = internalCluster().startNodesAsync(2).get();
+        List<String> nodesIds = internalCluster().startNodes(2);
         final String node_1 = nodesIds.get(0);
         final String node_2 = nodesIds.get(1);
 
@@ -113,11 +113,10 @@ public class SimpleNodesInfoIT extends ESIntegTestCase {
     }
 
     public void testAllocatedProcessors() throws Exception {
-        List<String> nodesIds = internalCluster().
-                startNodesAsync(
+        List<String> nodesIds = internalCluster().startNodes(
                         Settings.builder().put(EsExecutors.PROCESSORS_SETTING.getKey(), 3).build(),
                         Settings.builder().put(EsExecutors.PROCESSORS_SETTING.getKey(), 6).build()
-                ).get();
+                );
 
         final String node_1 = nodesIds.get(0);
         final String node_2 = nodesIds.get(1);
diff --git a/core/src/test/java/org/elasticsearch/recovery/FullRollingRestartIT.java b/core/src/test/java/org/elasticsearch/recovery/FullRollingRestartIT.java
index dc38867705..50035e1027 100644
--- a/core/src/test/java/org/elasticsearch/recovery/FullRollingRestartIT.java
+++ b/core/src/test/java/org/elasticsearch/recovery/FullRollingRestartIT.java
@@ -126,7 +126,7 @@ public class FullRollingRestartIT extends ESIntegTestCase {
     public void testNoRebalanceOnRollingRestart() throws Exception {
         // see https://github.com/elastic/elasticsearch/issues/14387
         internalCluster().startMasterOnlyNode(Settings.EMPTY);
-        internalCluster().startDataOnlyNodesAsync(3).get();
+        internalCluster().startDataOnlyNodes(3);
         /**
          * We start 3 nodes and a dedicated master. Restart on of the data-nodes and ensure that we got no relocations.
          * Yet we have 6 shards 0 replica so that means if the restarting node comes back both other nodes are subject
diff --git a/core/src/test/java/org/elasticsearch/recovery/RelocationIT.java b/core/src/test/java/org/elasticsearch/recovery/RelocationIT.java
index cd93a9fef2..2017b2796b 100644
--- a/core/src/test/java/org/elasticsearch/recovery/RelocationIT.java
+++ b/core/src/test/java/org/elasticsearch/recovery/RelocationIT.java
@@ -470,7 +470,7 @@ public class RelocationIT extends ESIntegTestCase {
             Stream.generate(() -> Settings.builder().put("node.attr.color", "blue").build()).limit(halfNodes),
             Stream.generate(() -> Settings.builder().put("node.attr.color", "red").build()).limit(halfNodes)
             ).toArray(Settings[]::new);
-        List<String> nodes = internalCluster().startNodesAsync(nodeSettings).get();
+        List<String> nodes = internalCluster().startNodes(nodeSettings);
         String[] blueNodes = nodes.subList(0, halfNodes).stream().toArray(String[]::new);
         String[] redNodes = nodes.subList(halfNodes, nodes.size()).stream().toArray(String[]::new);
         logger.info("blue nodes: {}", (Object)blueNodes);
diff --git a/core/src/test/java/org/elasticsearch/snapshots/DedicatedClusterSnapshotRestoreIT.java b/core/src/test/java/org/elasticsearch/snapshots/DedicatedClusterSnapshotRestoreIT.java
index 2375b7519c..b1c46b35b6 100644
--- a/core/src/test/java/org/elasticsearch/snapshots/DedicatedClusterSnapshotRestoreIT.java
+++ b/core/src/test/java/org/elasticsearch/snapshots/DedicatedClusterSnapshotRestoreIT.java
@@ -621,7 +621,7 @@ public class DedicatedClusterSnapshotRestoreIT extends AbstractSnapshotIntegTest
     public void testThatSensitiveRepositorySettingsAreNotExposed() throws Exception {
         Settings nodeSettings = Settings.builder().put().build();
         logger.info("--> start two nodes");
-        internalCluster().startNodesAsync(2, nodeSettings).get();
+        internalCluster().startNodes(2, nodeSettings);
         // Register mock repositories
         client().admin().cluster().preparePutRepository("test-repo")
                 .setType("mock").setSettings(Settings.builder()