diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
index 3e5bea320da..69bd6110f25 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/RawAsyncHBaseAdmin.java
@@ -1,4 +1,4 @@
-/**
+/*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
@@ -21,7 +21,6 @@ import static org.apache.hadoop.hbase.HConstants.HIGH_QOS;
 import static org.apache.hadoop.hbase.TableName.META_TABLE_NAME;
 import static org.apache.hadoop.hbase.util.FutureUtils.addListener;
 import static org.apache.hadoop.hbase.util.FutureUtils.unwrapCompletionException;
-
 import com.google.protobuf.Message;
 import com.google.protobuf.RpcChannel;
 import java.io.IOException;
@@ -46,7 +45,6 @@ import java.util.function.Supplier;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
-import org.apache.commons.io.IOUtils;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.AsyncMetaTableAccessor;
 import org.apache.hadoop.hbase.CacheEvictionStats;
@@ -99,14 +97,12 @@ import org.apache.hadoop.hbase.util.ForeignExceptionUtil;
 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.RpcCallback;
 import org.apache.hbase.thirdparty.io.netty.util.HashedWheelTimer;
 import org.apache.hbase.thirdparty.io.netty.util.Timeout;
 import org.apache.hbase.thirdparty.io.netty.util.TimerTask;
-
 import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.shaded.protobuf.RequestConverter;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.AccessControlProtos;
@@ -755,7 +751,8 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
   }
 
   @Override
-  public CompletableFuture<Void> addColumnFamily(TableName tableName, ColumnFamilyDescriptor columnFamily) {
+  public CompletableFuture<Void> addColumnFamily(
+      TableName tableName, ColumnFamilyDescriptor columnFamily) {
     return this.<AddColumnRequest, AddColumnResponse> procedureCall(tableName,
       RequestConverter.buildAddColumnRequest(tableName, columnFamily, ng.getNonceGroup(),
         ng.newNonce()), (s, c, req, done) -> s.addColumn(c, req, done), (resp) -> resp.getProcId(),
@@ -809,10 +806,10 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
         .<NamespaceDescriptor> newMasterCaller()
         .action(
           (controller, stub) -> this
-              .<GetNamespaceDescriptorRequest, GetNamespaceDescriptorResponse, NamespaceDescriptor> call(
-                controller, stub, RequestConverter.buildGetNamespaceDescriptorRequest(name), (s, c,
-                    req, done) -> s.getNamespaceDescriptor(c, req, done), (resp) -> ProtobufUtil
-                    .toNamespaceDescriptor(resp.getNamespaceDescriptor()))).call();
+              .<GetNamespaceDescriptorRequest, GetNamespaceDescriptorResponse, NamespaceDescriptor>
+                  call(controller, stub, RequestConverter.buildGetNamespaceDescriptorRequest(name),
+                    (s, c, req, done) -> s.getNamespaceDescriptor(c, req, done), (resp)
+                      -> ProtobufUtil.toNamespaceDescriptor(resp.getNamespaceDescriptor()))).call();
   }
 
   @Override
@@ -830,13 +827,12 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
   @Override
   public CompletableFuture<List<NamespaceDescriptor>> listNamespaceDescriptors() {
     return this
-        .<List<NamespaceDescriptor>> newMasterCaller()
-        .action(
-          (controller, stub) -> this
-              .<ListNamespaceDescriptorsRequest, ListNamespaceDescriptorsResponse, List<NamespaceDescriptor>> call(
-                controller, stub, ListNamespaceDescriptorsRequest.newBuilder().build(), (s, c, req,
-                    done) -> s.listNamespaceDescriptors(c, req, done), (resp) -> ProtobufUtil
-                    .toNamespaceDescriptorList(resp))).call();
+        .<List<NamespaceDescriptor>> newMasterCaller().action((controller, stub) -> this
+              .<ListNamespaceDescriptorsRequest, ListNamespaceDescriptorsResponse,
+                  List<NamespaceDescriptor>> call(controller, stub,
+                  ListNamespaceDescriptorsRequest.newBuilder().build(), (s, c, req, done) ->
+                      s.listNamespaceDescriptors(c, req, done),
+                    (resp) -> ProtobufUtil.toNamespaceDescriptorList(resp))).call();
   }
 
   @Override
@@ -1080,10 +1076,7 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
   private CompletableFuture<List<HRegionLocation>> getTableHRegionLocations(TableName tableName) {
     if (TableName.META_TABLE_NAME.equals(tableName)) {
       CompletableFuture<List<HRegionLocation>> future = new CompletableFuture<>();
-      // For meta table, we use zk to fetch all locations.
-      ConnectionRegistry registry = ConnectionRegistryFactory.getRegistry(
-          connection.getConfiguration());
-      addListener(registry.getMetaRegionLocations(), (metaRegions, err) -> {
+      addListener(connection.registry.getMetaRegionLocations(), (metaRegions, err) -> {
         if (err != null) {
           future.completeExceptionally(err);
         } else if (metaRegions == null || metaRegions.isEmpty() ||
@@ -1092,8 +1085,6 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
         } else {
           future.complete(Collections.singletonList(metaRegions.getDefaultRegionLocation()));
         }
-        // close the registry.
-        IOUtils.closeQuietly(registry);
       });
       return future;
     } else {
@@ -1689,11 +1680,10 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
   @Override
   public CompletableFuture<ReplicationPeerConfig> getReplicationPeerConfig(String peerId) {
     return this.<ReplicationPeerConfig> newMasterCaller().action((controller, stub) -> this
-      .<GetReplicationPeerConfigRequest, GetReplicationPeerConfigResponse, ReplicationPeerConfig> call(
-        controller, stub, RequestConverter.buildGetReplicationPeerConfigRequest(peerId),
-        (s, c, req, done) -> s.getReplicationPeerConfig(c, req, done),
-        (resp) -> ReplicationPeerConfigUtil.convert(resp.getPeerConfig())))
-      .call();
+      .<GetReplicationPeerConfigRequest, GetReplicationPeerConfigResponse, ReplicationPeerConfig>
+          call(controller, stub, RequestConverter.buildGetReplicationPeerConfigRequest(peerId),
+            (s, c, req, done) -> s.getReplicationPeerConfig(c, req, done),
+            (resp) -> ReplicationPeerConfigUtil.convert(resp.getPeerConfig()))).call();
   }
 
   @Override
@@ -1710,13 +1700,13 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
   @Override
   public CompletableFuture<Void> transitReplicationPeerSyncReplicationState(String peerId,
       SyncReplicationState clusterState) {
-    return this
-      .<TransitReplicationPeerSyncReplicationStateRequest, TransitReplicationPeerSyncReplicationStateResponse> procedureCall(
+    return this.<TransitReplicationPeerSyncReplicationStateRequest,
+        TransitReplicationPeerSyncReplicationStateResponse> procedureCall(
         RequestConverter.buildTransitReplicationPeerSyncReplicationStateRequest(peerId,
           clusterState),
-        (s, c, req, done) -> s.transitReplicationPeerSyncReplicationState(c, req, done),
-        (resp) -> resp.getProcId(), new ReplicationProcedureBiConsumer(peerId,
-          () -> "TRANSIT_REPLICATION_PEER_SYNCHRONOUS_REPLICATION_STATE"));
+          (s, c, req, done) -> s.transitReplicationPeerSyncReplicationState(c, req, done),
+          (resp) -> resp.getProcId(), new ReplicationProcedureBiConsumer(peerId,
+            () -> "TRANSIT_REPLICATION_PEER_SYNCHRONOUS_REPLICATION_STATE"));
   }
 
   @Override
@@ -1786,11 +1776,8 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
     return this
         .<List<ReplicationPeerDescription>> newMasterCaller()
         .action(
-          (controller, stub) -> this
-              .<ListReplicationPeersRequest, ListReplicationPeersResponse, List<ReplicationPeerDescription>> call(
-                controller,
-                stub,
-                request,
+          (controller, stub) -> this.<ListReplicationPeersRequest, ListReplicationPeersResponse,
+              List<ReplicationPeerDescription>> call(controller, stub, request,
                 (s, c, req, done) -> s.listReplicationPeers(c, req, done),
                 (resp) -> resp.getPeerDescList().stream()
                     .map(ReplicationPeerConfigUtil::toReplicationPeerDescription)
@@ -2299,11 +2286,13 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
   }
 
   @Override
-  public CompletableFuture<Void> decommissionRegionServers(List<ServerName> servers, boolean offload) {
+  public CompletableFuture<Void> decommissionRegionServers(
+      List<ServerName> servers, boolean offload) {
     return this.<Void> newMasterCaller()
         .action((controller, stub) -> this
           .<DecommissionRegionServersRequest, DecommissionRegionServersResponse, Void> call(
-            controller, stub, RequestConverter.buildDecommissionRegionServersRequest(servers, offload),
+            controller, stub,
+              RequestConverter.buildDecommissionRegionServersRequest(servers, offload),
             (s, c, req, done) -> s.decommissionRegionServers(c, req, done), resp -> null))
         .call();
   }
@@ -2325,11 +2314,11 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
   public CompletableFuture<Void> recommissionRegionServer(ServerName server,
       List<byte[]> encodedRegionNames) {
     return this.<Void> newMasterCaller()
-        .action((controller, stub) -> this
-          .<RecommissionRegionServerRequest, RecommissionRegionServerResponse, Void> call(controller,
-            stub, RequestConverter.buildRecommissionRegionServerRequest(server, encodedRegionNames),
-            (s, c, req, done) -> s.recommissionRegionServer(c, req, done), resp -> null))
-        .call();
+        .action((controller, stub) ->
+            this.<RecommissionRegionServerRequest, RecommissionRegionServerResponse, Void> call(
+                controller, stub, RequestConverter.buildRecommissionRegionServerRequest(
+                    server, encodedRegionNames), (s, c, req, done) -> s.recommissionRegionServer(
+                        c, req, done), resp -> null)).call();
   }
 
   /**
@@ -2395,7 +2384,6 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
    * Get the region info for the passed region name. The region name may be a full region name or
    * encoded region name. If the region does not found, then it'll throw an UnknownRegionException
    * wrapped by a {@link CompletableFuture}
-   * @param regionNameOrEncodedRegionName
    * @return region info, wrapped by a {@link CompletableFuture}
    */
   private CompletableFuture<RegionInfo> getRegionInfo(byte[] regionNameOrEncodedRegionName) {
@@ -2886,10 +2874,11 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
         .<List<SecurityCapability>> newMasterCaller()
         .action(
           (controller, stub) -> this
-              .<SecurityCapabilitiesRequest, SecurityCapabilitiesResponse, List<SecurityCapability>> call(
-                controller, stub, SecurityCapabilitiesRequest.newBuilder().build(), (s, c, req,
-                    done) -> s.getSecurityCapabilities(c, req, done), (resp) -> ProtobufUtil
-                    .toSecurityCapabilityList(resp.getCapabilitiesList()))).call();
+              .<SecurityCapabilitiesRequest, SecurityCapabilitiesResponse, List<SecurityCapability>>
+                  call(controller, stub, SecurityCapabilitiesRequest.newBuilder().build(),
+                    (s, c, req, done) -> s.getSecurityCapabilities(c, req, done),
+                    (resp) -> ProtobufUtil.toSecurityCapabilityList(resp.getCapabilitiesList())))
+        .call();
   }
 
   @Override
@@ -3066,14 +3055,10 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
     MajorCompactionTimestampRequest request =
         MajorCompactionTimestampRequest.newBuilder()
             .setTableName(ProtobufUtil.toProtoTableName(tableName)).build();
-    return this
-        .<Optional<Long>> newMasterCaller()
-        .action(
-          (controller, stub) -> this
-              .<MajorCompactionTimestampRequest, MajorCompactionTimestampResponse, Optional<Long>> call(
-                controller, stub, request,
-                (s, c, req, done) -> s.getLastMajorCompactionTimestamp(c, req, done),
-                ProtobufUtil::toOptionalTimestamp)).call();
+    return this.<Optional<Long>> newMasterCaller().action((controller, stub) ->
+        this.<MajorCompactionTimestampRequest, MajorCompactionTimestampResponse, Optional<Long>>
+            call(controller, stub, request, (s, c, req, done) -> s.getLastMajorCompactionTimestamp(
+                c, req, done), ProtobufUtil::toOptionalTimestamp)).call();
   }
 
   @Override
@@ -3213,11 +3198,10 @@ class RawAsyncHBaseAdmin implements AsyncAdmin {
   public CompletableFuture<Boolean> isBalancerEnabled() {
     return this
         .<Boolean> newMasterCaller()
-        .action(
-          (controller, stub) -> this.<IsBalancerEnabledRequest, IsBalancerEnabledResponse, Boolean> call(
-            controller, stub, RequestConverter.buildIsBalancerEnabledRequest(),
-            (s, c, req, done) -> s.isBalancerEnabled(c, req, done), (resp) -> resp.getEnabled()))
-        .call();
+        .action((controller, stub) ->
+              this.<IsBalancerEnabledRequest, IsBalancerEnabledResponse, Boolean> call(controller,
+            stub, RequestConverter.buildIsBalancerEnabledRequest(), (s, c, req, done)
+                  -> s.isBalancerEnabled(c, req, done), (resp) -> resp.getEnabled())).call();
   }
 
   @Override