Replace internal usages of 'master' term in 'server/src/main' directory (#2519)

* Replace internal usages of 'master' terminology in server/src/main directory

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Restore rename DISCOVERED_MASTER in ClusterHealthResponse

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Rename two methods in unit tests

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Replace master word in ClusterState

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Replace master word in LeaderChecker JoinHelper JoinTaskExecutor

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Replace master word in more classes

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Replace master word in more classes

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Replace master word in more classes

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Replace master word in more classes

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Replace master word in more classes

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Replace master word in more classes

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Replace master word in DiscoveryNodes classes

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Replace master word in more classes

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Correct mistakes

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Adjust format by spotlessApply task

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Change MASTER__NODE_BOOTSTRAPPED_MSG in test

Signed-off-by: Tianli Feng <ftianli@amazon.com>

* Fix SnapshotDisruptionIT by renaming to cluster-manager

Signed-off-by: Tianli Feng <ftianli@amazon.com>

Author: Tianli Feng

server/src/internalClusterTest/java/org/opensearch/cluster/coordination/UnsafeBootstrapAndDetachCommandIT.java

@@ -111,7 +111,7 @@ private MockTerminal executeCommand(
     private MockTerminal unsafeBootstrap(Environment environment, boolean abort, Boolean applyClusterReadOnlyBlock) throws Exception {
         final MockTerminal terminal = executeCommand(new UnsafeBootstrapMasterCommand(), environment, 0, abort, applyClusterReadOnlyBlock);
         assertThat(terminal.getOutput(), containsString(UnsafeBootstrapMasterCommand.CONFIRMATION_MSG));
-        assertThat(terminal.getOutput(), containsString(UnsafeBootstrapMasterCommand.MASTER_NODE_BOOTSTRAPPED_MSG));
+        assertThat(terminal.getOutput(), containsString(UnsafeBootstrapMasterCommand.CLUSTER_MANAGER_NODE_BOOTSTRAPPED_MSG));
         return terminal;
     }
 
@@ -171,7 +171,7 @@ public void testBootstrapNotMasterEligible() {
         final Environment environment = TestEnvironment.newEnvironment(
             Settings.builder().put(nonMasterNode(internalCluster().getDefaultSettings())).build()
         );
-        expectThrows(() -> unsafeBootstrap(environment), UnsafeBootstrapMasterCommand.NOT_MASTER_NODE_MSG);
+        expectThrows(() -> unsafeBootstrap(environment), UnsafeBootstrapMasterCommand.NOT_CLUSTER_MANAGER_NODE_MSG);
     }
 
     public void testBootstrapNoDataFolder() {

server/src/internalClusterTest/java/org/opensearch/discovery/SnapshotDisruptionIT.java

@@ -248,7 +248,7 @@ public void testMasterFailOverDuringShardSnapshots() throws Exception {
 
         blockDataNode(repoName, dataNode);
 
-        logger.info("--> create snapshot via master node client");
+        logger.info("--> create snapshot via cluster-manager node client");
         final ActionFuture<CreateSnapshotResponse> snapshotResponse = internalCluster().masterClient()
             .admin()
             .cluster()
@@ -272,7 +272,7 @@ public void testMasterFailOverDuringShardSnapshots() throws Exception {
             SnapshotException.class,
             () -> snapshotResponse.actionGet(TimeValue.timeValueSeconds(30L))
         );
-        assertThat(sne.getMessage(), endsWith("no longer master"));
+        assertThat(sne.getMessage(), endsWith("no longer cluster-manager"));
     }
 
     private void assertSnapshotExists(String repository, String snapshot) {

server/src/internalClusterTest/java/org/opensearch/env/NodeRepurposeCommandIT.java

@@ -136,7 +136,7 @@ private void executeRepurposeCommand(Settings settings, int expectedIndexCount,
         boolean verbose = randomBoolean();
         Settings settingsWithPath = Settings.builder().put(internalCluster().getDefaultSettings()).put(settings).build();
         Matcher<String> matcher = allOf(
-            containsString(NodeRepurposeCommand.noMasterMessage(expectedIndexCount, expectedShardCount, 0)),
+            containsString(NodeRepurposeCommand.noClusterManagerMessage(expectedIndexCount, expectedShardCount, 0)),
             NodeRepurposeCommandTests.conditionalNot(containsString("test-repurpose"), verbose == false)
         );
         NodeRepurposeCommandTests.verifySuccess(settingsWithPath, matcher, verbose);

server/src/main/java/org/opensearch/OpenSearchException.java

@@ -785,7 +785,7 @@ private enum OpenSearchExceptionHandle {
             2,
             UNKNOWN_VERSION_ADDED
         ),
-        MASTER_NOT_DISCOVERED_EXCEPTION(
+        CLUSTER_MANAGER_NOT_DISCOVERED_EXCEPTION(
             org.opensearch.discovery.MasterNotDiscoveredException.class,
             org.opensearch.discovery.MasterNotDiscoveredException::new,
             3,
@@ -1496,7 +1496,7 @@ private enum OpenSearchExceptionHandle {
             143,
             UNKNOWN_VERSION_ADDED
         ),
-        NOT_MASTER_EXCEPTION(
+        NOT_CLUSTER_MANAGER_EXCEPTION(
             org.opensearch.cluster.NotMasterException.class,
             org.opensearch.cluster.NotMasterException::new,
             144,

server/src/main/java/org/opensearch/action/admin/cluster/allocation/TransportClusterAllocationExplainAction.java

@@ -64,7 +64,7 @@
 
 /**
  * The {@code TransportClusterAllocationExplainAction} is responsible for actually executing the explanation of a shard's allocation on the
- * master node in the cluster.
+ * cluster-manager node in the cluster.
  */
 public class TransportClusterAllocationExplainAction extends TransportMasterNodeAction<
     ClusterAllocationExplainRequest,

server/src/main/java/org/opensearch/action/admin/cluster/health/ClusterHealthResponse.java

@@ -90,7 +90,7 @@ public class ClusterHealthResponse extends ActionResponse implements StatusToXCo
             // ClusterStateHealth fields
             int numberOfNodes = (int) parsedObjects[i++];
             int numberOfDataNodes = (int) parsedObjects[i++];
-            boolean hasDiscoveredMaster = Boolean.TRUE.equals(parsedObjects[i++]);
+            boolean hasDiscoveredClusterManager = Boolean.TRUE.equals(parsedObjects[i++]);
             int activeShards = (int) parsedObjects[i++];
             int relocatingShards = (int) parsedObjects[i++];
             int activePrimaryShards = (int) parsedObjects[i++];
@@ -118,7 +118,7 @@ public class ClusterHealthResponse extends ActionResponse implements StatusToXCo
                 unassignedShards,
                 numberOfNodes,
                 numberOfDataNodes,
-                hasDiscoveredMaster,
+                hasDiscoveredClusterManager,
                 activeShardsPercent,
                 status,
                 indices

server/src/main/java/org/opensearch/action/admin/cluster/health/TransportClusterHealthAction.java

@@ -218,11 +218,11 @@ public void clusterStateProcessed(String source, ClusterState oldState, ClusterS
                     @Override
                     public void onNoLongerMaster(String source) {
                         logger.trace(
-                            "stopped being master while waiting for events with priority [{}]. retrying.",
+                            "stopped being cluster-manager while waiting for events with priority [{}]. retrying.",
                             request.waitForEvents()
                         );
                         // TransportMasterNodeAction implements the retry logic, which is triggered by passing a NotMasterException
-                        listener.onFailure(new NotMasterException("no longer master. source: [" + source + "]"));
+                        listener.onFailure(new NotMasterException("no longer cluster-manager. source: [" + source + "]"));
                     }
 
                     @Override

server/src/main/java/org/opensearch/action/admin/cluster/repositories/cleanup/TransportCleanupRepositoryAction.java

@@ -73,12 +73,12 @@
  * <ol>
  *     <li>Check that there are no running repository cleanup, snapshot create, or snapshot delete actions
  *     and add an entry for the repository that is to be cleaned up to {@link RepositoryCleanupInProgress}</li>
- *     <li>Run cleanup actions on the repository. Note, these are executed exclusively on the master node.
+ *     <li>Run cleanup actions on the repository. Note, these are executed exclusively on the cluster-manager node.
  *     For the precise operations execute see {@link BlobStoreRepository#cleanup}</li>
  *     <li>Remove the entry in {@link RepositoryCleanupInProgress} in the first step.</li>
  * </ol>
  *
- * On master failover during the cleanup operation it is simply removed from the cluster state. This is safe because the logic in
+ * On cluster-manager failover during the cleanup operation it is simply removed from the cluster state. This is safe because the logic in
  * {@link BlobStoreRepository#cleanup} ensures that the repository state id has not changed between creation of the cluster state entry
  * and any delete/write operations. TODO: This will not work if we also want to clean up at the shard level as those will involve writes
  *                                        as well as deletes.
@@ -119,7 +119,7 @@ public TransportCleanupRepositoryAction(
         );
         this.repositoriesService = repositoriesService;
         this.snapshotsService = snapshotsService;
-        // We add a state applier that will remove any dangling repository cleanup actions on master failover.
+        // We add a state applier that will remove any dangling repository cleanup actions on cluster-manager failover.
         // This is safe to do since cleanups will increment the repository state id before executing any operations to prevent concurrent
         // operations from corrupting the repository. This is the same safety mechanism used by snapshot deletes.
         if (DiscoveryNode.isMasterNode(clusterService.getSettings())) {
@@ -136,7 +136,7 @@ private static void addClusterStateApplier(ClusterService clusterService) {
                     return;
                 }
                 clusterService.submitStateUpdateTask(
-                    "clean up repository cleanup task after master failover",
+                    "clean up repository cleanup task after cluster-manager failover",
                     new ClusterStateUpdateTask() {
                         @Override
                         public ClusterState execute(ClusterState currentState) {

server/src/main/java/org/opensearch/action/admin/cluster/settings/TransportClusterUpdateSettingsAction.java

@@ -155,11 +155,11 @@ public void onAckTimeout() {
                 }
 
                 private void reroute(final boolean updateSettingsAcked) {
-                    // We're about to send a second update task, so we need to check if we're still the elected master
-                    // For example the minimum_master_node could have been breached and we're no longer elected master,
+                    // We're about to send a second update task, so we need to check if we're still the elected cluster-manager
+                    // For example the minimum_master_node could have been breached and we're no longer elected cluster-manager,
                     // so we should *not* execute the reroute.
                     if (!clusterService.state().nodes().isLocalNodeElectedMaster()) {
-                        logger.debug("Skipping reroute after cluster update settings, because node is no longer master");
+                        logger.debug("Skipping reroute after cluster update settings, because node is no longer cluster-manager");
                         listener.onResponse(
                             new ClusterUpdateSettingsResponse(
                                 updateSettingsAcked,
@@ -198,7 +198,7 @@ protected ClusterUpdateSettingsResponse newResponse(boolean acknowledged) {
                             @Override
                             public void onNoLongerMaster(String source) {
                                 logger.debug(
-                                    "failed to preform reroute after cluster settings were updated - current node is no longer a master"
+                                    "failed to preform reroute after cluster settings were updated - current node is no longer a cluster-manager"
                                 );
                                 listener.onResponse(
                                     new ClusterUpdateSettingsResponse(

server/src/main/java/org/opensearch/action/admin/cluster/snapshots/restore/RestoreClusterStateListener.java

@@ -69,8 +69,8 @@ public void clusterChanged(ClusterChangedEvent changedEvent) {
         final RestoreInProgress.Entry prevEntry = restoreInProgress(changedEvent.previousState(), uuid);
         final RestoreInProgress.Entry newEntry = restoreInProgress(changedEvent.state(), uuid);
         if (prevEntry == null) {
-            // When there is a master failure after a restore has been started, this listener might not be registered
-            // on the current master and as such it might miss some intermediary cluster states due to batching.
+            // When there is a cluster-manager failure after a restore has been started, this listener might not be registered
+            // on the current cluster-manager and as such it might miss some intermediary cluster states due to batching.
             // Clean up listener in that case and acknowledge completion of restore operation to client.
             clusterService.removeListener(this);
             listener.onResponse(new RestoreSnapshotResponse((RestoreInfo) null));

server/src/main/java/org/opensearch/action/admin/cluster/snapshots/status/TransportSnapshotsStatusAction.java

@@ -221,8 +221,8 @@ private void buildResponse(
                                         // Unlikely edge case:
                                         // Data node has finished snapshotting the shard but the cluster state has not yet been updated
                                         // to reflect this. We adjust the status to show up as snapshot metadata being written because
-                                        // technically if the data node failed before successfully reporting DONE state to master, then
-                                        // this shards state would jump to a failed state.
+                                        // technically if the data node failed before successfully reporting DONE state to cluster-manager,
+                                        // then this shards state would jump to a failed state.
                                         shardStatus = new SnapshotIndexShardStatus(
                                             shardEntry.key,
                                             SnapshotIndexShardStage.FINALIZE,
@@ -406,7 +406,7 @@ private SnapshotInfo snapshot(SnapshotsInProgress snapshotsInProgress, String re
     /**
      * Returns status of shards currently finished snapshots
      * <p>
-     * This method is executed on master node and it's complimentary to the
+     * This method is executed on cluster-manager node and it's complimentary to the
      * {@link SnapshotShardsService#currentSnapshotShards(Snapshot)} because it
      * returns similar information but for already finished snapshots.
      * </p>

server/src/main/java/org/opensearch/action/admin/cluster/state/ClusterStateResponse.java

@@ -108,20 +108,20 @@ public boolean equals(Object o) {
         if (o == null || getClass() != o.getClass()) return false;
         ClusterStateResponse response = (ClusterStateResponse) o;
         return waitForTimedOut == response.waitForTimedOut && Objects.equals(clusterName, response.clusterName) &&
-        // Best effort. Only compare cluster state version and master node id,
+        // Best effort. Only compare cluster state version and cluster-manager node id,
         // because cluster state doesn't implement equals()
             Objects.equals(getVersion(clusterState), getVersion(response.clusterState))
-            && Objects.equals(getMasterNodeId(clusterState), getMasterNodeId(response.clusterState));
+            && Objects.equals(getClusterManagerNodeId(clusterState), getClusterManagerNodeId(response.clusterState));
     }
 
     @Override
     public int hashCode() {
-        // Best effort. Only use cluster state version and master node id,
+        // Best effort. Only use cluster state version and cluster-manager node id,
         // because cluster state doesn't implement hashcode()
-        return Objects.hash(clusterName, getVersion(clusterState), getMasterNodeId(clusterState), waitForTimedOut);
+        return Objects.hash(clusterName, getVersion(clusterState), getClusterManagerNodeId(clusterState), waitForTimedOut);
     }
 
-    private static String getMasterNodeId(ClusterState clusterState) {
+    private static String getClusterManagerNodeId(ClusterState clusterState) {
         if (clusterState == null) {
             return null;
         }

server/src/main/java/org/opensearch/action/admin/cluster/state/TransportClusterStateAction.java

@@ -138,7 +138,7 @@ public void onNewClusterState(ClusterState newState) {
                         } else {
                             listener.onFailure(
                                 new NotMasterException(
-                                    "master stepped down waiting for metadata version " + request.waitForMetadataVersion()
+                                    "cluster-manager stepped down waiting for metadata version " + request.waitForMetadataVersion()
                                 )
                             );
                         }

server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsNodeResponse.java

@@ -85,7 +85,7 @@ public NodeStats nodeStats() {
     }
 
     /**
-     * Cluster Health Status, only populated on master nodes.
+     * Cluster Health Status, only populated on cluster-manager nodes.
      */
     @Nullable
     public ClusterHealthStatus clusterStatus() {

server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsResponse.java

@@ -60,7 +60,7 @@ public class ClusterStatsResponse extends BaseNodesResponse<ClusterStatsNodeResp
     public ClusterStatsResponse(StreamInput in) throws IOException {
         super(in);
         timestamp = in.readVLong();
-        // it may be that the master switched on us while doing the operation. In this case the status may be null.
+        // it may be that the cluster-manager switched on us while doing the operation. In this case the status may be null.
         status = in.readOptionalWriteable(ClusterHealthStatus::readFrom);
 
         String clusterUUID = null;
@@ -93,7 +93,7 @@ public ClusterStatsResponse(
         indicesStats = new ClusterStatsIndices(nodes, MappingStats.of(state), AnalysisStats.of(state));
         ClusterHealthStatus status = null;
         for (ClusterStatsNodeResponse response : nodes) {
-            // only the master node populates the status
+            // only the cluster-manager node populates the status
             if (response.clusterStatus() != null) {
                 status = response.clusterStatus();
                 break;

server/src/main/java/org/opensearch/action/admin/indices/dangling/package-info.java

@@ -33,10 +33,10 @@
  * <ul>
  * <li>A user overflows the index graveyard by deleting more than 500 indices while a node is offline and then the node rejoins the
  * cluster</li>
- * <li>A node (unsafely) moves from one cluster to another, perhaps because the original cluster lost all its master nodes</li>
+ * <li>A node (unsafely) moves from one cluster to another, perhaps because the original cluster lost all its cluster-manager nodes</li>
  * <li>A user (unsafely) meddles with the contents of the data path, maybe restoring an old index folder from a backup</li>
  * <li>A disk partially fails and the user has no replicas and no snapshots and wants to (unsafely) recover whatever they can</li>
- * <li>A cluster loses all master nodes and those are (unsafely) restored from backup, but the backup does not contain the index</li>
+ * <li>A cluster loses all cluster-manager nodes and those are (unsafely) restored from backup, but the backup does not contain the index</li>
  * </ul>
  *
  * <p>The classes in this package form an API for managing dangling indices, allowing them to be listed, imported or deleted.

server/src/main/java/org/opensearch/action/bulk/BulkPrimaryExecutionContext.java

@@ -61,7 +61,7 @@ enum ItemProcessingState {
         TRANSLATED,
         /**
          * the request can not execute with the current mapping and should wait for a new mapping
-         * to arrive from the master. A mapping request for the needed changes has already been
+         * to arrive from the cluster-manager. A mapping request for the needed changes has already been
          * submitted
          */
         WAIT_FOR_MAPPING_UPDATE,
@@ -144,7 +144,7 @@ public boolean isOperationExecuted() {
         return currentItemState == ItemProcessingState.EXECUTED;
     }
 
-    /** returns true if the request needs to wait for a mapping update to arrive from the master */
+    /** returns true if the request needs to wait for a mapping update to arrive from the cluster-manager */
     public boolean requiresWaitingForMappingUpdate() {
         return currentItemState == ItemProcessingState.WAIT_FOR_MAPPING_UPDATE;
     }
@@ -216,7 +216,7 @@ public <T extends DocWriteRequest<T>> T getRequestToExecute() {
         return (T) requestToExecute;
     }
 
-    /** indicates that the current operation can not be completed and needs to wait for a new mapping from the master */
+    /** indicates that the current operation can not be completed and needs to wait for a new mapping from the cluster-manager */
     public void markAsRequiringMappingUpdate() {
         assert assertInvariants(ItemProcessingState.TRANSLATED);
         currentItemState = ItemProcessingState.WAIT_FOR_MAPPING_UPDATE;

server/src/main/java/org/opensearch/action/bulk/MappingUpdatePerformer.java

@@ -39,7 +39,7 @@
 public interface MappingUpdatePerformer {
 
     /**
-     * Update the mappings on the master.
+     * Update the mappings on the cluster-manager.
      */
     void updateMappings(Mapping update, ShardId shardId, ActionListener<Void> listener);
 

server/src/main/java/org/opensearch/action/bulk/TransportShardBulkAction.java

@@ -621,7 +621,7 @@ private static Engine.Result performOpOnReplica(
                 throw new IllegalStateException("Unexpected request operation type on replica: " + docWriteRequest.opType().getLowercase());
         }
         if (result.getResultType() == Engine.Result.Type.MAPPING_UPDATE_REQUIRED) {
-            // Even though the primary waits on all nodes to ack the mapping changes to the master
+            // Even though the primary waits on all nodes to ack the mapping changes to the cluster-manager
             // (see MappingUpdatedAction.updateMappingOnMaster) we still need to protect against missing mappings
             // and wait for them. The reason is concurrent requests. Request r1 which has new field f triggers a
             // mapping update. Assume that that update is first applied on the primary, and only later on the replica