diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/MasterNotRunningException.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/MasterNotRunningException.java
index 1ff17ac12cc..35cdecba9bb 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/MasterNotRunningException.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/MasterNotRunningException.java
@@ -18,15 +18,13 @@
  */
 package org.apache.hadoop.hbase;
 
-import java.io.IOException;
-
 import org.apache.yetus.audience.InterfaceAudience;
 
 /**
  * Thrown if the master is not running
  */
 @InterfaceAudience.Public
-public class MasterNotRunningException extends IOException {
+public class MasterNotRunningException extends HBaseIOException {
   private static final long serialVersionUID = (1L << 23) - 1L;
   /** default constructor */
   public MasterNotRunningException() {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClusterConnection.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClusterConnection.java
index 7294559d757..3e055b0eb34 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClusterConnection.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ClusterConnection.java
@@ -21,7 +21,6 @@ package org.apache.hadoop.hbase.client;
 
 import java.io.IOException;
 import java.util.List;
-
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HRegionLocation;
 import org.apache.hadoop.hbase.MasterNotRunningException;
@@ -29,12 +28,12 @@ import org.apache.hadoop.hbase.RegionLocations;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.ZooKeeperConnectionException;
-import org.apache.yetus.audience.InterfaceAudience;
 import org.apache.hadoop.hbase.client.backoff.ClientBackoffPolicy;
 import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
+import org.apache.yetus.audience.InterfaceAudience;
+
 import org.apache.hadoop.hbase.shaded.protobuf.generated.AdminProtos.AdminService;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos.ClientService;
-import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.MasterService;
 
 /** Internal methods on Connection that should not be used by user code. */
 @InterfaceAudience.Private
@@ -224,7 +223,7 @@ public interface ClusterConnection extends Connection {
   /**
    * Returns a {@link MasterKeepAliveConnection} to the active master
    */
-  MasterService.BlockingInterface getMaster() throws IOException;
+  MasterKeepAliveConnection getMaster() throws IOException;
 
   /**
    * Get the admin service for master.
@@ -258,9 +257,8 @@ public interface ClusterConnection extends Connection {
    * @return Location of row.
    * @throws IOException if a remote or network exception occurs
    */
-  HRegionLocation getRegionLocation(TableName tableName, byte [] row,
-    boolean reload)
-  throws IOException;
+  HRegionLocation getRegionLocation(TableName tableName, byte[] row, boolean reload)
+      throws IOException;
 
   /**
    * Clear any caches that pertain to server name <code>sn</code>.
@@ -268,24 +266,6 @@ public interface ClusterConnection extends Connection {
    */
   void clearCaches(final ServerName sn);
 
-  /**
-   * This function allows HBaseAdmin and potentially others to get a shared MasterService
-   * connection.
-   * @return The shared instance. Never returns null.
-   * @throws MasterNotRunningException if master is not running
-   * @deprecated Since 0.96.0
-   */
-  @Deprecated
-  MasterKeepAliveConnection getKeepAliveMasterService()
-  throws MasterNotRunningException;
-
-  /**
-   * @param serverName of server to check
-   * @return true if the server is known as dead, false otherwise.
-   * @deprecated internal method, do not use thru ClusterConnection */
-  @Deprecated
-  boolean isDeadServer(ServerName serverName);
-
   /**
    * @return Nonce generator for this ClusterConnection; may be null if disabled in configuration.
    */
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java
index a5a01881681..6408044c391 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java
@@ -538,6 +538,12 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
     return this.conf;
   }
 
+  private void checkClosed() throws DoNotRetryIOException {
+    if (this.closed) {
+      throw new DoNotRetryIOException(toString() + " closed");
+    }
+  }
+
   /**
    * @return true if the master is running, throws an exception otherwise
    * @throws org.apache.hadoop.hbase.MasterNotRunningException - if the master is not running
@@ -545,21 +551,24 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
    */
   @Deprecated
   @Override
-  public boolean isMasterRunning()
-  throws MasterNotRunningException, ZooKeeperConnectionException {
+  public boolean isMasterRunning() throws MasterNotRunningException, ZooKeeperConnectionException {
     // When getting the master connection, we check it's running,
     // so if there is no exception, it means we've been able to get a
     // connection on a running master
-    MasterKeepAliveConnection m = getKeepAliveMasterService();
+    MasterKeepAliveConnection m;
+    try {
+      m = getKeepAliveMasterService();
+    } catch (IOException e) {
+      throw new MasterNotRunningException(e);
+    }
     m.close();
     return true;
   }
 
   @Override
-  public HRegionLocation getRegionLocation(final TableName tableName,
-      final byte [] row, boolean reload)
-  throws IOException {
-    return reload? relocateRegion(tableName, row): locateRegion(tableName, row);
+  public HRegionLocation getRegionLocation(final TableName tableName, final byte[] row,
+      boolean reload) throws IOException {
+    return reload ? relocateRegion(tableName, row) : locateRegion(tableName, row);
   }
 
 
@@ -576,9 +585,7 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
   @Override
   public boolean isTableAvailable(final TableName tableName, @Nullable final byte[][] splitKeys)
       throws IOException {
-    if (this.closed) {
-      throw new IOException(toString() + " closed");
-    }
+    checkClosed();
     try {
       if (!isTableEnabled(tableName)) {
         LOG.debug("Table " + tableName + " not enabled");
@@ -641,8 +648,7 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
     return locations == null ? null : locations.getRegionLocation();
   }
 
-  @Override
-  public boolean isDeadServer(ServerName sn) {
+  private boolean isDeadServer(ServerName sn) {
     if (clusterStatusListener == null) {
       return false;
     } else {
@@ -679,19 +685,19 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
   }
 
   @Override
-  public HRegionLocation locateRegion(
-      final TableName tableName, final byte[] row) throws IOException{
+  public HRegionLocation locateRegion(final TableName tableName, final byte[] row)
+      throws IOException {
     RegionLocations locations = locateRegion(tableName, row, true, true);
     return locations == null ? null : locations.getRegionLocation();
   }
 
   @Override
-  public HRegionLocation relocateRegion(final TableName tableName,
-      final byte [] row) throws IOException{
-    RegionLocations locations =  relocateRegion(tableName, row,
-      RegionReplicaUtil.DEFAULT_REPLICA_ID);
-    return locations == null ? null :
-      locations.getRegionLocation(RegionReplicaUtil.DEFAULT_REPLICA_ID);
+  public HRegionLocation relocateRegion(final TableName tableName, final byte[] row)
+      throws IOException {
+    RegionLocations locations =
+      relocateRegion(tableName, row, RegionReplicaUtil.DEFAULT_REPLICA_ID);
+    return locations == null ? null
+      : locations.getRegionLocation(RegionReplicaUtil.DEFAULT_REPLICA_ID);
   }
 
   @Override
@@ -708,22 +714,17 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
   }
 
   @Override
-  public RegionLocations locateRegion(final TableName tableName,
-    final byte [] row, boolean useCache, boolean retry)
-  throws IOException {
+  public RegionLocations locateRegion(final TableName tableName, final byte[] row, boolean useCache,
+      boolean retry) throws IOException {
     return locateRegion(tableName, row, useCache, retry, RegionReplicaUtil.DEFAULT_REPLICA_ID);
   }
 
   @Override
-  public RegionLocations locateRegion(final TableName tableName,
-    final byte [] row, boolean useCache, boolean retry, int replicaId)
-  throws IOException {
-    if (this.closed) {
-      throw new DoNotRetryIOException(toString() + " closed");
-    }
-    if (tableName== null || tableName.getName().length == 0) {
-      throw new IllegalArgumentException(
-          "table name cannot be null or zero length");
+  public RegionLocations locateRegion(final TableName tableName, final byte[] row, boolean useCache,
+      boolean retry, int replicaId) throws IOException {
+    checkClosed();
+    if (tableName == null || tableName.getName().length == 0) {
+      throw new IllegalArgumentException("table name cannot be null or zero length");
     }
     if (tableName.equals(TableName.META_TABLE_NAME)) {
       return locateMeta(tableName, useCache, replicaId);
@@ -1170,6 +1171,7 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
   @Override
   public AdminProtos.AdminService.BlockingInterface getAdmin(ServerName serverName)
       throws IOException {
+    checkClosed();
     if (isDeadServer(serverName)) {
       throw new RegionServerStoppedException(serverName + " is dead.");
     }
@@ -1184,6 +1186,7 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
 
   @Override
   public BlockingInterface getClient(ServerName serverName) throws IOException {
+    checkClosed();
     if (isDeadServer(serverName)) {
       throw new RegionServerStoppedException(serverName + " is dead.");
     }
@@ -1199,7 +1202,7 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
   final MasterServiceState masterServiceState = new MasterServiceState(this);
 
   @Override
-  public MasterProtos.MasterService.BlockingInterface getMaster() throws MasterNotRunningException {
+  public MasterKeepAliveConnection getMaster() throws IOException {
     return getKeepAliveMasterService();
   }
 
@@ -1207,20 +1210,11 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
     mss.userCount++;
   }
 
-  @Override
-  public MasterKeepAliveConnection getKeepAliveMasterService()
-  throws MasterNotRunningException {
+  private MasterKeepAliveConnection getKeepAliveMasterService() throws IOException {
     synchronized (masterLock) {
       if (!isKeepAliveMasterConnectedAndRunning(this.masterServiceState)) {
         MasterServiceStubMaker stubMaker = new MasterServiceStubMaker();
-        try {
-          this.masterServiceState.stub = stubMaker.makeStub();
-        } catch (MasterNotRunningException ex) {
-          throw ex;
-        } catch (IOException e) {
-          // rethrow as MasterNotRunningException so that we can keep the method sig
-          throw new MasterNotRunningException(e);
-        }
+        this.masterServiceState.stub = stubMaker.makeStub();
       }
       resetMasterServiceState(this.masterServiceState);
     }
@@ -1955,9 +1949,7 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
 
   @Override
   public TableState getTableState(TableName tableName) throws IOException {
-    if (this.closed) {
-      throw new IOException(toString() + " closed");
-    }
+    checkClosed();
     TableState tableState = MetaTableAccessor.getTableState(this, tableName);
     if (tableState == null) {
       throw new TableNotFoundException(tableName);
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionUtils.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionUtils.java
index c9e994f9aa2..63ef865ed42 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionUtils.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionUtils.java
@@ -31,12 +31,10 @@ import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.concurrent.TimeUnit;
-
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellComparator;
 import org.apache.hadoop.hbase.HConstants;
-import org.apache.hadoop.hbase.MasterNotRunningException;
 import org.apache.hadoop.hbase.PrivateCellUtil;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
@@ -51,9 +49,11 @@ import org.apache.hadoop.net.DNS;
 import org.apache.yetus.audience.InterfaceAudience;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+
 import org.apache.hbase.thirdparty.com.google.common.annotations.VisibleForTesting;
 import org.apache.hbase.thirdparty.com.google.common.base.Preconditions;
 import org.apache.hbase.thirdparty.com.google.protobuf.ServiceException;
+
 import org.apache.hadoop.hbase.shaded.protobuf.ResponseConverter;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.AdminProtos.AdminService;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ClientProtos.ClientService;
@@ -155,11 +155,11 @@ public final class ConnectionUtils {
     }
 
     @Override
-    public MasterKeepAliveConnection getKeepAliveMasterService() throws MasterNotRunningException {
+    public MasterKeepAliveConnection getMaster() throws IOException {
       if (this.localHostClient instanceof MasterService.BlockingInterface) {
         return new ShortCircuitMasterConnection((MasterService.BlockingInterface)this.localHostClient);
       }
-      return super.getKeepAliveMasterService();
+      return super.getMaster();
     }
   }
 
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HTable.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HTable.java
index a4289e939a7..1a119790834 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HTable.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/HTable.java
@@ -162,10 +162,7 @@ public class HTable implements Table {
       final RpcRetryingCallerFactory rpcCallerFactory,
       final RpcControllerFactory rpcControllerFactory,
       final ExecutorService pool) {
-    if (connection == null || connection.isClosed()) {
-      throw new IllegalArgumentException("Connection is null or closed.");
-    }
-    this.connection = connection;
+    this.connection = Preconditions.checkNotNull(connection, "connection is null");
     this.configuration = connection.getConfiguration();
     this.connConfiguration = connection.getConnectionConfiguration();
     if (pool == null) {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterCallable.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterCallable.java
index f56ebd54f76..7ae97314c48 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterCallable.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/MasterCallable.java
@@ -20,15 +20,14 @@ package org.apache.hadoop.hbase.client;
 
 import java.io.Closeable;
 import java.io.IOException;
-
-import org.apache.hadoop.hbase.HRegionInfo;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.ipc.HBaseRpcController;
 import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
-import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.yetus.audience.InterfaceAudience;
 
+import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
+
 /**
  * A RetryingCallable for Master RPC operations.
  * Implement the #rpcCall method. It will be retried on error. See its javadoc and the javadoc of
@@ -55,7 +54,7 @@ abstract class MasterCallable<V> implements RetryingCallable<V>, Closeable {
 
   @Override
   public void prepare(boolean reload) throws IOException {
-    this.master = this.connection.getKeepAliveMasterService();
+    this.master = this.connection.getMaster();
   }
 
   @Override
@@ -139,7 +138,7 @@ abstract class MasterCallable<V> implements RetryingCallable<V>, Closeable {
   }
 
   private static boolean isMetaRegion(final byte[] regionName) {
-    return Bytes.equals(regionName, HRegionInfo.FIRST_META_REGIONINFO.getRegionName())
-        || Bytes.equals(regionName, HRegionInfo.FIRST_META_REGIONINFO.getEncodedNameAsBytes());
+    return Bytes.equals(regionName, RegionInfoBuilder.FIRST_META_REGIONINFO.getRegionName()) ||
+      Bytes.equals(regionName, RegionInfoBuilder.FIRST_META_REGIONINFO.getEncodedNameAsBytes());
   }
 }
diff --git a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestSnapshotFromAdmin.java b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestSnapshotFromAdmin.java
index 387e9dd6c15..dba1a369522 100644
--- a/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestSnapshotFromAdmin.java
+++ b/hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestSnapshotFromAdmin.java
@@ -92,7 +92,7 @@ public class TestSnapshotFromAdmin {
     // mock the master admin to our mock
     MasterKeepAliveConnection mockMaster = Mockito.mock(MasterKeepAliveConnection.class);
     Mockito.when(mockConnection.getConfiguration()).thenReturn(conf);
-    Mockito.when(mockConnection.getKeepAliveMasterService()).thenReturn(mockMaster);
+    Mockito.when(mockConnection.getMaster()).thenReturn(mockMaster);
     // we need a real retrying caller
     RpcRetryingCallerFactory callerFactory = new RpcRetryingCallerFactory(conf);
     RpcControllerFactory controllerFactory = Mockito.mock(RpcControllerFactory.class);
@@ -163,7 +163,7 @@ public class TestSnapshotFromAdmin {
 
     // mock the master connection
     MasterKeepAliveConnection master = Mockito.mock(MasterKeepAliveConnection.class);
-    Mockito.when(mockConnection.getKeepAliveMasterService()).thenReturn(master);
+    Mockito.when(mockConnection.getMaster()).thenReturn(master);
     SnapshotResponse response = SnapshotResponse.newBuilder().setExpectedTimeout(0).build();
     Mockito.when(
       master.snapshot((RpcController) Mockito.any(), Mockito.any()))
diff --git a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestHBaseAdminNoCluster.java b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestHBaseAdminNoCluster.java
index bab0fe9ab22..a1026a943ab 100644
--- a/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestHBaseAdminNoCluster.java
+++ b/hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestHBaseAdminNoCluster.java
@@ -102,7 +102,7 @@ public class TestHBaseAdminNoCluster {
     Mockito.when(masterAdmin.createTable((RpcController)Mockito.any(),
       (CreateTableRequest)Mockito.any())).
         thenThrow(new ServiceException("Test fail").initCause(new PleaseHoldException("test")));
-    Mockito.when(connection.getKeepAliveMasterService()).thenReturn(masterAdmin);
+    Mockito.when(connection.getMaster()).thenReturn(masterAdmin);
     Admin admin = new HBaseAdmin(connection);
     try {
       HTableDescriptor htd = new HTableDescriptor(TableName.valueOf(name.getMethodName()));
@@ -304,7 +304,7 @@ public class TestHBaseAdminNoCluster {
             throw new MasterNotRunningException(); // all methods will throw an exception
           }
         });
-    Mockito.when(connection.getKeepAliveMasterService()).thenReturn(masterAdmin);
+    Mockito.when(connection.getMaster()).thenReturn(masterAdmin);
     RpcControllerFactory rpcControllerFactory = Mockito.mock(RpcControllerFactory.class);
     Mockito.when(connection.getRpcControllerFactory()).thenReturn(rpcControllerFactory);
     Mockito.when(rpcControllerFactory.newController()).thenReturn(