diff --git a/server/src/main/java/org/opensearch/cluster/coordination/Coordinator.java b/server/src/main/java/org/opensearch/cluster/coordination/Coordinator.java
index 56d585d81e9dc..e3a72faace106 100644
--- a/server/src/main/java/org/opensearch/cluster/coordination/Coordinator.java
+++ b/server/src/main/java/org/opensearch/cluster/coordination/Coordinator.java
@@ -911,7 +911,7 @@ assert getLocalNode().equals(applierState.nodes().getMasterNode())
 
                 final boolean activePublication = currentPublication.map(CoordinatorPublication::isActiveForCurrentLeader).orElse(false);
                 if (becomingClusterManager && activePublication == false) {
-                    // cluster state update task to become cluster-manager is submitted to ClusterManagerService,
+                    // cluster state update task to become cluster-manager is submitted to MasterService,
                     // but publication has not started yet
                     assert followersChecker.getKnownFollowers().isEmpty() : followersChecker.getKnownFollowers();
                 } else {
diff --git a/test/framework/src/main/java/org/opensearch/cluster/coordination/AbstractCoordinatorTestCase.java b/test/framework/src/main/java/org/opensearch/cluster/coordination/AbstractCoordinatorTestCase.java
index fb18aa1b5749b..19551b0adecb2 100644
--- a/test/framework/src/main/java/org/opensearch/cluster/coordination/AbstractCoordinatorTestCase.java
+++ b/test/framework/src/main/java/org/opensearch/cluster/coordination/AbstractCoordinatorTestCase.java
@@ -557,7 +557,7 @@ void stabilise(long stabilisationDurationMillis) {
             final ClusterNode leader = getAnyLeader();
             final long leaderTerm = leader.coordinator.getCurrentTerm();
 
-            final int pendingTaskCount = leader.clusterManagerService.getFakeMasterServicePendingTaskCount();
+            final int pendingTaskCount = leader.masterService.getFakeMasterServicePendingTaskCount();
             runFor((pendingTaskCount + 1) * DEFAULT_CLUSTER_STATE_UPDATE_DELAY, "draining task queue");
 
             final Matcher<Long> isEqualToLeaderVersion = equalTo(leader.coordinator.getLastAcceptedState().getVersion());
@@ -1025,7 +1025,7 @@ class ClusterNode {
             private final DiscoveryNode localNode;
             final MockPersistedState persistedState;
             final Settings nodeSettings;
-            private AckedFakeThreadPoolMasterService clusterManagerService;
+            private AckedFakeThreadPoolMasterService masterService;
             private DisruptableClusterApplierService clusterApplierService;
             private ClusterService clusterService;
             TransportService transportService;
@@ -1105,7 +1105,7 @@ protected Optional<DisruptableMockTransport> getDisruptableMockTransport(Transpo
                     null,
                     emptySet()
                 );
-                clusterManagerService = new AckedFakeThreadPoolMasterService(
+                masterService = new AckedFakeThreadPoolMasterService(
                     localNode.getId(),
                     "test",
                     threadPool,
@@ -1119,7 +1119,7 @@ protected Optional<DisruptableMockTransport> getDisruptableMockTransport(Transpo
                     deterministicTaskQueue,
                     threadPool
                 );
-                clusterService = new ClusterService(settings, clusterSettings, clusterManagerService, clusterApplierService);
+                clusterService = new ClusterService(settings, clusterSettings, masterService, clusterApplierService);
                 clusterService.setNodeConnectionsService(
                     new NodeConnectionsService(clusterService.getSettings(), threadPool, transportService)
                 );
@@ -1134,7 +1134,7 @@ protected Optional<DisruptableMockTransport> getDisruptableMockTransport(Transpo
                     transportService,
                     writableRegistry(),
                     allocationService,
-                    clusterManagerService,
+                    masterService,
                     this::getPersistedState,
                     Cluster.this::provideSeedHosts,
                     clusterApplierService,
@@ -1144,7 +1144,7 @@ protected Optional<DisruptableMockTransport> getDisruptableMockTransport(Transpo
                     getElectionStrategy(),
                     nodeHealthService
                 );
-                clusterManagerService.setClusterStatePublisher(coordinator);
+                masterService.setClusterStatePublisher(coordinator);
                 final GatewayService gatewayService = new GatewayService(
                     settings,
                     allocationService,
@@ -1331,11 +1331,11 @@ AckCollector submitUpdateTask(
                 onNode(() -> {
                     logger.trace("[{}] submitUpdateTask: enqueueing [{}]", localNode.getId(), source);
                     final long submittedTerm = coordinator.getCurrentTerm();
-                    clusterManagerService.submitStateUpdateTask(source, new ClusterStateUpdateTask() {
+                    masterService.submitStateUpdateTask(source, new ClusterStateUpdateTask() {
                         @Override
                         public ClusterState execute(ClusterState currentState) {
                             assertThat(currentState.term(), greaterThanOrEqualTo(submittedTerm));
-                            clusterManagerService.nextAckCollector = ackCollector;
+                            masterService.nextAckCollector = ackCollector;
                             return clusterStateUpdate.apply(currentState);
                         }
 
diff --git a/test/framework/src/test/java/org/opensearch/cluster/service/FakeThreadPoolMasterServiceTests.java b/test/framework/src/test/java/org/opensearch/cluster/service/FakeThreadPoolMasterServiceTests.java
index dabeeb6742ec4..b4cdb0b33391a 100644
--- a/test/framework/src/test/java/org/opensearch/cluster/service/FakeThreadPoolMasterServiceTests.java
+++ b/test/framework/src/test/java/org/opensearch/cluster/service/FakeThreadPoolMasterServiceTests.java
@@ -84,21 +84,21 @@ public void testFakeClusterManagerService() {
         doAnswer(invocationOnMock -> runnableTasks.add((Runnable) invocationOnMock.getArguments()[0])).when(executorService).execute(any());
         when(mockThreadPool.generic()).thenReturn(executorService);
 
-        FakeThreadPoolMasterService clusterManagerService = new FakeThreadPoolMasterService(
+        FakeThreadPoolMasterService masterService = new FakeThreadPoolMasterService(
             "test_node",
             "test",
             mockThreadPool,
             runnableTasks::add
         );
-        clusterManagerService.setClusterStateSupplier(lastClusterStateRef::get);
-        clusterManagerService.setClusterStatePublisher((event, publishListener, ackListener) -> {
+        masterService.setClusterStateSupplier(lastClusterStateRef::get);
+        masterService.setClusterStatePublisher((event, publishListener, ackListener) -> {
             lastClusterStateRef.set(event.state());
             publishingCallback.set(publishListener);
         });
-        clusterManagerService.start();
+        masterService.start();
 
         AtomicBoolean firstTaskCompleted = new AtomicBoolean();
-        clusterManagerService.submitStateUpdateTask("test1", new ClusterStateUpdateTask() {
+        masterService.submitStateUpdateTask("test1", new ClusterStateUpdateTask() {
             @Override
             public ClusterState execute(ClusterState currentState) {
                 return ClusterState.builder(currentState)
@@ -138,7 +138,7 @@ public void onFailure(String source, Exception e) {
         assertThat(runnableTasks.size(), equalTo(0));
 
         AtomicBoolean secondTaskCompleted = new AtomicBoolean();
-        clusterManagerService.submitStateUpdateTask("test2", new ClusterStateUpdateTask() {
+        masterService.submitStateUpdateTask("test2", new ClusterStateUpdateTask() {
             @Override
             public ClusterState execute(ClusterState currentState) {
                 return ClusterState.builder(currentState)