HBASE-17337 list replication peers request should be routed through master

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.hbase.client;
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.Future;
@@ -48,6 +49,7 @@ import org.apache.hadoop.hbase.quotas.QuotaRetriever;
 import org.apache.hadoop.hbase.quotas.QuotaSettings;
 import org.apache.hadoop.hbase.regionserver.wal.FailedLogCloseException;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
+import org.apache.hadoop.hbase.replication.ReplicationPeerDescription;
 import org.apache.hadoop.hbase.snapshot.HBaseSnapshotException;
 import org.apache.hadoop.hbase.snapshot.RestoreSnapshotException;
 import org.apache.hadoop.hbase.snapshot.SnapshotCreationException;
@@ -1879,6 +1881,35 @@ public interface Admin extends Abortable, Closeable {
       final ReplicationPeerConfig peerConfig) throws IOException {
   }
 
+  /**
+   * Return a list of replication peers.
+   * @return a list of replication peers description
+   * @throws IOException
+   */
+  default List<ReplicationPeerDescription> listReplicationPeers() throws IOException {
+    return new ArrayList<>();
+  }
+
+  /**
+   * Return a list of replication peers.
+   * @param regex The regular expression to match peer id
+   * @return a list of replication peers description
+   * @throws IOException
+   */
+  default List<ReplicationPeerDescription> listReplicationPeers(String regex) throws IOException {
+    return new ArrayList<>();
+  }
+
+  /**
+   * Return a list of replication peers.
+   * @param pattern The compiled regular expression to match peer id
+   * @return a list of replication peers description
+   * @throws IOException
+   */
+  default List<ReplicationPeerDescription> listReplicationPeers(Pattern pattern) throws IOException {
+    return new ArrayList<>();
+  }
+
   /**
    * Mark a region server as draining to prevent additional regions from getting assigned to it.
    * @param servers List of region servers to drain.

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionImplementation.java

@@ -102,6 +102,8 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.Enabl
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.EnableReplicationPeerResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.GetReplicationPeerConfigRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.GetReplicationPeerConfigResponse;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.RemoveReplicationPeerRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.RemoveReplicationPeerResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigRequest;
@@ -1711,6 +1713,12 @@ class ConnectionImplementation implements ClusterConnection, Closeable {
           throws ServiceException {
         return stub.updateReplicationPeerConfig(controller, request);
       }
+
+      @Override
+      public ListReplicationPeersResponse listReplicationPeers(RpcController controller,
+          ListReplicationPeersRequest request) throws ServiceException {
+        return stub.listReplicationPeers(controller, request);
+      }
     };
   }
 

hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java

@@ -79,6 +79,7 @@ import org.apache.hadoop.hbase.quotas.QuotaRetriever;
 import org.apache.hadoop.hbase.quotas.QuotaSettings;
 import org.apache.hadoop.hbase.regionserver.wal.FailedLogCloseException;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
+import org.apache.hadoop.hbase.replication.ReplicationPeerDescription;
 import org.apache.hadoop.hbase.shaded.com.google.protobuf.ServiceException;
 import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.shaded.protobuf.RequestConverter;
@@ -172,6 +173,7 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.TruncateTa
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.TruncateTableResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.UnassignRegionRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ProcedureProtos;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.GetReplicationPeerConfigResponse;
 import org.apache.hadoop.hbase.snapshot.ClientSnapshotDescriptionUtils;
 import org.apache.hadoop.hbase.snapshot.HBaseSnapshotException;
@@ -3832,6 +3834,35 @@ public class HBaseAdmin implements Admin {
     });
   }
 
+  @Override
+  public List<ReplicationPeerDescription> listReplicationPeers() throws IOException {
+    return listReplicationPeers((Pattern)null);
+  }
+
+  @Override
+  public List<ReplicationPeerDescription> listReplicationPeers(String regex) throws IOException {
+    return listReplicationPeers(Pattern.compile(regex));
+  }
+
+  @Override
+  public List<ReplicationPeerDescription> listReplicationPeers(Pattern pattern)
+      throws IOException {
+    return executeCallable(new MasterCallable<List<ReplicationPeerDescription>>(getConnection(),
+        getRpcControllerFactory()) {
+      @Override
+      protected List<ReplicationPeerDescription> rpcCall() throws Exception {
+        List<ReplicationProtos.ReplicationPeerDescription> peersList = master.listReplicationPeers(
+          getRpcController(), RequestConverter.buildListReplicationPeersRequest(pattern))
+            .getPeerDescList();
+        List<ReplicationPeerDescription> result = new ArrayList<>(peersList.size());
+        for (ReplicationProtos.ReplicationPeerDescription peer : peersList) {
+          result.add(ReplicationSerDeHelper.toReplicationPeerDescription(peer));
+        }
+        return result;
+      }
+    });
+  }
+
   @Override
   public void drainRegionServers(List<ServerName> servers) throws IOException {
     final List<HBaseProtos.ServerName> pbServers = new ArrayList<HBaseProtos.ServerName>();

hbase-client/src/main/java/org/apache/hadoop/hbase/client/replication/ReplicationAdmin.java

@@ -29,6 +29,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.TreeMap;
 import java.util.Map.Entry;
 import java.util.Set;
 
@@ -39,6 +40,7 @@ import org.apache.hadoop.hbase.Abortable;
 import org.apache.hadoop.hbase.HColumnDescriptor;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.ReplicationPeerNotFoundException;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.TableNotFoundException;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
@@ -52,6 +54,7 @@ import org.apache.hadoop.hbase.replication.ReplicationException;
 import org.apache.hadoop.hbase.replication.ReplicationFactory;
 import org.apache.hadoop.hbase.replication.ReplicationPeer;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
+import org.apache.hadoop.hbase.replication.ReplicationPeerDescription;
 import org.apache.hadoop.hbase.replication.ReplicationPeerZKImpl;
 import org.apache.hadoop.hbase.replication.ReplicationPeers;
 import org.apache.hadoop.hbase.replication.ReplicationQueuesClient;
@@ -238,13 +241,19 @@ public class ReplicationAdmin implements Closeable {
   /**
    * Get the number of slave clusters the local cluster has.
    * @return number of slave clusters
+   * @throws IOException
    */
-  public int getPeersCount() {
+  public int getPeersCount() throws IOException {
-    return this.replicationPeers.getAllPeerIds().size();
+    return this.admin.listReplicationPeers().size();
   }
 
-  public Map<String, ReplicationPeerConfig> listPeerConfigs() {
+  public Map<String, ReplicationPeerConfig> listPeerConfigs() throws IOException {
-    return this.replicationPeers.getAllPeerConfigs();
+    List<ReplicationPeerDescription> peers = this.admin.listReplicationPeers();
+    Map<String, ReplicationPeerConfig> result = new TreeMap<String, ReplicationPeerConfig>();
+    for (ReplicationPeerDescription peer : peers) {
+      result.put(peer.getPeerId(), peer.getPeerConfig());
+    }
+    return result;
   }
 
   public ReplicationPeerConfig getPeerConfig(String id) throws IOException {
@@ -402,8 +411,12 @@ public class ReplicationAdmin implements Closeable {
    * an IllegalArgumentException is thrown if it doesn't exist
    * @return true if replication is enabled to that peer, false if it isn't
    */
-  public boolean getPeerState(String id) throws ReplicationException {
+  public boolean getPeerState(String id) throws ReplicationException, IOException {
-    return this.replicationPeers.getStatusOfPeerFromBackingStore(id);
+    List<ReplicationPeerDescription> peers = admin.listReplicationPeers(id);
+    if (peers.isEmpty() || !id.equals(peers.get(0).getPeerId())) {
+      throw new ReplicationPeerNotFoundException(id);
+    }
+    return peers.get(0).isEnabled();
   }
 
   @Override
@@ -577,7 +590,7 @@ public class ReplicationAdmin implements Closeable {
   }
 
   @VisibleForTesting
-  List<ReplicationPeer> listReplicationPeers() {
+  List<ReplicationPeer> listReplicationPeers() throws IOException {
     Map<String, ReplicationPeerConfig> peers = listPeerConfigs();
     if (peers == null || peers.size() <= 0) {
       return null;

hbase-client/src/main/java/org/apache/hadoop/hbase/client/replication/ReplicationSerDeHelper.java

@@ -31,6 +31,7 @@ import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
+import org.apache.hadoop.hbase.replication.ReplicationPeerDescription;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.Strings;
 
@@ -293,7 +294,7 @@ public final class ReplicationSerDeHelper {
     return peerConfig;
   }
 
-  public static ReplicationProtos.ReplicationPeer convert(ReplicationPeerConfig  peerConfig) {
+  public static ReplicationProtos.ReplicationPeer convert(ReplicationPeerConfig peerConfig) {
     ReplicationProtos.ReplicationPeer.Builder builder = ReplicationProtos.ReplicationPeer.newBuilder();
     if (peerConfig.getClusterKey() != null) {
       builder.setClusterkey(peerConfig.getClusterKey());
@@ -343,4 +344,26 @@ public final class ReplicationSerDeHelper {
     byte[] bytes = convert(peerConfig).toByteArray();
     return ProtobufUtil.prependPBMagic(bytes);
   }
+
+  public static ReplicationPeerDescription toReplicationPeerDescription(
+      ReplicationProtos.ReplicationPeerDescription desc) {
+    boolean enabled = ReplicationProtos.ReplicationState.State.ENABLED == desc.getState()
+        .getState();
+    ReplicationPeerConfig config = convert(desc.getConfig());
+    return new ReplicationPeerDescription(desc.getId(), enabled, config);
+  }
+
+  public static ReplicationProtos.ReplicationPeerDescription toProtoReplicationPeerDescription(
+      ReplicationPeerDescription desc) {
+    ReplicationProtos.ReplicationPeerDescription.Builder builder = ReplicationProtos.ReplicationPeerDescription
+        .newBuilder();
+    builder.setId(desc.getPeerId());
+    ReplicationProtos.ReplicationState.Builder stateBuilder = ReplicationProtos.ReplicationState
+        .newBuilder();
+    stateBuilder.setState(desc.isEnabled() ? ReplicationProtos.ReplicationState.State.ENABLED
+        : ReplicationProtos.ReplicationState.State.DISABLED);
+    builder.setState(stateBuilder.build());
+    builder.setConfig(convert(desc.getPeerConfig()));
+    return builder.build();
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/replication/ReplicationPeerDescription.java

@@ -0,0 +1,59 @@
+/**
+ * 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
+ * regarding copyright ownership.  The ASF 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.apache.hadoop.hbase.replication;
+
+import org.apache.hadoop.hbase.classification.InterfaceAudience;
+import org.apache.hadoop.hbase.classification.InterfaceStability;
+
+/**
+ * The POJO equivalent of ReplicationProtos.ReplicationPeerDescription
+ */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
+public class ReplicationPeerDescription {
+
+  private final String id;
+  private final boolean enabled;
+  private final ReplicationPeerConfig config;
+
+  public ReplicationPeerDescription(String id, boolean enabled, ReplicationPeerConfig config) {
+    this.id = id;
+    this.enabled = enabled;
+    this.config = config;
+  }
+
+  public String getPeerId() {
+    return this.id;
+  }
+
+  public boolean isEnabled() {
+    return this.enabled;
+  }
+
+  public ReplicationPeerConfig getPeerConfig() {
+    return this.config;
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder builder = new StringBuilder("id : ").append(id);
+    builder.append(", enabled : " + enabled);
+    builder.append(", config : " + config);
+    return builder.toString();
+  }
+}

hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java

@@ -91,6 +91,7 @@ import org.apache.hadoop.hbase.quotas.QuotaType;
 import org.apache.hadoop.hbase.quotas.ThrottleType;
 import org.apache.hadoop.hbase.replication.ReplicationLoadSink;
 import org.apache.hadoop.hbase.replication.ReplicationLoadSource;
+import org.apache.hadoop.hbase.replication.ReplicationPeerDescription;
 import org.apache.hadoop.hbase.security.User;
 import org.apache.hadoop.hbase.security.visibility.Authorizations;
 import org.apache.hadoop.hbase.security.visibility.CellVisibility;
@@ -158,6 +159,7 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.GetTableDe
 import org.apache.hadoop.hbase.shaded.protobuf.generated.QuotaProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionServerReportRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.RegionServerStatusProtos.RegionServerStartupRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.WALProtos;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.WALProtos.BulkLoadDescriptor;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.WALProtos.CompactionDescriptor;

hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/RequestConverter.java

@@ -116,6 +116,7 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.AddRe
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.DisableReplicationPeerRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.EnableReplicationPeerRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.GetReplicationPeerConfigRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.RemoveReplicationPeerRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigRequest;
 import org.apache.hadoop.hbase.util.Bytes;
@@ -1613,4 +1614,12 @@ public final class RequestConverter {
     builder.setPeerConfig(ReplicationSerDeHelper.convert(peerConfig));
     return builder.build();
   }
+
+  public static ListReplicationPeersRequest buildListReplicationPeersRequest(Pattern pattern) {
+    ListReplicationPeersRequest.Builder builder = ListReplicationPeersRequest.newBuilder();
+    if (pattern != null) {
+      builder.setRegex(pattern.toString());
+    }
+    return builder.build();
+  }
 }

hbase-protocol-shaded/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/generated/MasterProtos.java

@@ -69797,6 +69797,18 @@ public final class MasterProtos {
           org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigRequest request,
           org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcCallback<org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigResponse> done);
 
+      /**
+       * <pre>
+       ** Returns a list of replication peers 
+       * </pre>
+       *
+       * <code>rpc ListReplicationPeers(.hbase.pb.ListReplicationPeersRequest) returns (.hbase.pb.ListReplicationPeersResponse);</code>
+       */
+      public abstract void listReplicationPeers(
+          org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcController controller,
+          org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest request,
+          org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcCallback<org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse> done);
+
       /**
        * <pre>
        ** Returns a list of ServerNames marked as draining. 
@@ -70350,6 +70362,14 @@ public final class MasterProtos {
           impl.updateReplicationPeerConfig(controller, request, done);
         }
 
+        @java.lang.Override
+        public  void listReplicationPeers(
+            org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcController controller,
+            org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest request,
+            org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcCallback<org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse> done) {
+          impl.listReplicationPeers(controller, request, done);
+        }
+
         @java.lang.Override
         public  void listDrainingRegionServers(
             org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcController controller,
@@ -70525,10 +70545,12 @@ public final class MasterProtos {
             case 63:
               return impl.updateReplicationPeerConfig(controller, (org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigRequest)request);
             case 64:
-              return impl.listDrainingRegionServers(controller, (org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersRequest)request);
+              return impl.listReplicationPeers(controller, (org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest)request);
             case 65:
-              return impl.drainRegionServers(controller, (org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersRequest)request);
+              return impl.listDrainingRegionServers(controller, (org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersRequest)request);
             case 66:
+              return impl.drainRegionServers(controller, (org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersRequest)request);
+            case 67:
               return impl.removeDrainFromRegionServers(controller, (org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersRequest)request);
             default:
               throw new java.lang.AssertionError("Can't get here.");
@@ -70673,10 +70695,12 @@ public final class MasterProtos {
             case 63:
               return org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigRequest.getDefaultInstance();
             case 64:
-              return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersRequest.getDefaultInstance();
+              return org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest.getDefaultInstance();
             case 65:
-              return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersRequest.getDefaultInstance();
+              return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersRequest.getDefaultInstance();
             case 66:
+              return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersRequest.getDefaultInstance();
+            case 67:
               return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersRequest.getDefaultInstance();
             default:
               throw new java.lang.AssertionError("Can't get here.");
@@ -70821,10 +70845,12 @@ public final class MasterProtos {
             case 63:
               return org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigResponse.getDefaultInstance();
             case 64:
-              return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersResponse.getDefaultInstance();
+              return org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse.getDefaultInstance();
             case 65:
-              return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersResponse.getDefaultInstance();
+              return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersResponse.getDefaultInstance();
             case 66:
+              return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersResponse.getDefaultInstance();
+            case 67:
               return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersResponse.getDefaultInstance();
             default:
               throw new java.lang.AssertionError("Can't get here.");
@@ -71631,6 +71657,18 @@ public final class MasterProtos {
         org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigRequest request,
         org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcCallback<org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigResponse> done);
 
+    /**
+     * <pre>
+     ** Returns a list of replication peers 
+     * </pre>
+     *
+     * <code>rpc ListReplicationPeers(.hbase.pb.ListReplicationPeersRequest) returns (.hbase.pb.ListReplicationPeersResponse);</code>
+     */
+    public abstract void listReplicationPeers(
+        org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcController controller,
+        org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest request,
+        org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcCallback<org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse> done);
+
     /**
      * <pre>
      ** Returns a list of ServerNames marked as draining. 
@@ -72010,16 +72048,21 @@ public final class MasterProtos {
               done));
           return;
         case 64:
+          this.listReplicationPeers(controller, (org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest)request,
+            org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcUtil.<org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse>specializeCallback(
+              done));
+          return;
+        case 65:
           this.listDrainingRegionServers(controller, (org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersRequest)request,
             org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcUtil.<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersResponse>specializeCallback(
               done));
           return;
-        case 65:
+        case 66:
           this.drainRegionServers(controller, (org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersRequest)request,
             org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcUtil.<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersResponse>specializeCallback(
               done));
           return;
-        case 66:
+        case 67:
           this.removeDrainFromRegionServers(controller, (org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersRequest)request,
             org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcUtil.<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersResponse>specializeCallback(
               done));
@@ -72167,10 +72210,12 @@ public final class MasterProtos {
         case 63:
           return org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigRequest.getDefaultInstance();
         case 64:
-          return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersRequest.getDefaultInstance();
+          return org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest.getDefaultInstance();
         case 65:
-          return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersRequest.getDefaultInstance();
+          return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersRequest.getDefaultInstance();
         case 66:
+          return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersRequest.getDefaultInstance();
+        case 67:
           return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersRequest.getDefaultInstance();
         default:
           throw new java.lang.AssertionError("Can't get here.");
@@ -72315,10 +72360,12 @@ public final class MasterProtos {
         case 63:
           return org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigResponse.getDefaultInstance();
         case 64:
-          return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersResponse.getDefaultInstance();
+          return org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse.getDefaultInstance();
         case 65:
-          return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersResponse.getDefaultInstance();
+          return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersResponse.getDefaultInstance();
         case 66:
+          return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersResponse.getDefaultInstance();
+        case 67:
           return org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersResponse.getDefaultInstance();
         default:
           throw new java.lang.AssertionError("Can't get here.");
@@ -73301,12 +73348,27 @@ public final class MasterProtos {
             org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigResponse.getDefaultInstance()));
       }
 
+      public  void listReplicationPeers(
+          org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcController controller,
+          org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest request,
+          org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcCallback<org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse> done) {
+        channel.callMethod(
+          getDescriptor().getMethods().get(64),
+          controller,
+          request,
+          org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse.getDefaultInstance(),
+          org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcUtil.generalizeCallback(
+            done,
+            org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse.class,
+            org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse.getDefaultInstance()));
+      }
+
       public  void listDrainingRegionServers(
           org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcController controller,
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersRequest request,
           org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcCallback<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersResponse> done) {
         channel.callMethod(
-          getDescriptor().getMethods().get(64),
+          getDescriptor().getMethods().get(65),
           controller,
           request,
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersResponse.getDefaultInstance(),
@@ -73321,7 +73383,7 @@ public final class MasterProtos {
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersRequest request,
           org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcCallback<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersResponse> done) {
         channel.callMethod(
-          getDescriptor().getMethods().get(65),
+          getDescriptor().getMethods().get(66),
           controller,
           request,
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersResponse.getDefaultInstance(),
@@ -73336,7 +73398,7 @@ public final class MasterProtos {
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersRequest request,
           org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcCallback<org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersResponse> done) {
         channel.callMethod(
-          getDescriptor().getMethods().get(66),
+          getDescriptor().getMethods().get(67),
           controller,
           request,
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersResponse.getDefaultInstance(),
@@ -73673,6 +73735,11 @@ public final class MasterProtos {
           org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigRequest request)
           throws org.apache.hadoop.hbase.shaded.com.google.protobuf.ServiceException;
 
+      public org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse listReplicationPeers(
+          org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcController controller,
+          org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest request)
+          throws org.apache.hadoop.hbase.shaded.com.google.protobuf.ServiceException;
+
       public org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersResponse listDrainingRegionServers(
           org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcController controller,
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersRequest request)
@@ -74464,12 +74531,24 @@ public final class MasterProtos {
       }
 
 
+      public org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse listReplicationPeers(
+          org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcController controller,
+          org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest request)
+          throws org.apache.hadoop.hbase.shaded.com.google.protobuf.ServiceException {
+        return (org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse) channel.callBlockingMethod(
+          getDescriptor().getMethods().get(64),
+          controller,
+          request,
+          org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse.getDefaultInstance());
+      }
+
+
       public org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersResponse listDrainingRegionServers(
           org.apache.hadoop.hbase.shaded.com.google.protobuf.RpcController controller,
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersRequest request)
           throws org.apache.hadoop.hbase.shaded.com.google.protobuf.ServiceException {
         return (org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersResponse) channel.callBlockingMethod(
-          getDescriptor().getMethods().get(64),
+          getDescriptor().getMethods().get(65),
           controller,
           request,
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.ListDrainingRegionServersResponse.getDefaultInstance());
@@ -74481,7 +74560,7 @@ public final class MasterProtos {
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersRequest request)
           throws org.apache.hadoop.hbase.shaded.com.google.protobuf.ServiceException {
         return (org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersResponse) channel.callBlockingMethod(
-          getDescriptor().getMethods().get(65),
+          getDescriptor().getMethods().get(66),
           controller,
           request,
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.DrainRegionServersResponse.getDefaultInstance());
@@ -74493,7 +74572,7 @@ public final class MasterProtos {
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersRequest request)
           throws org.apache.hadoop.hbase.shaded.com.google.protobuf.ServiceException {
         return (org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersResponse) channel.callBlockingMethod(
-          getDescriptor().getMethods().get(66),
+          getDescriptor().getMethods().get(67),
           controller,
           request,
           org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProtos.RemoveDrainFromRegionServersResponse.getDefaultInstance());
@@ -75319,7 +75398,7 @@ public final class MasterProtos {
       "\022)\n\013server_name\030\001 \003(\0132\024.hbase.pb.ServerN" +
       "ame\"&\n$RemoveDrainFromRegionServersRespo",
       "nse*(\n\020MasterSwitchType\022\t\n\005SPLIT\020\000\022\t\n\005ME" +
-      "RGE\020\0012\2301\n\rMasterService\022e\n\024GetSchemaAlte" +
+      "RGE\020\0012\3771\n\rMasterService\022e\n\024GetSchemaAlte" +
       "rStatus\022%.hbase.pb.GetSchemaAlterStatusR" +
       "equest\032&.hbase.pb.GetSchemaAlterStatusRe" +
       "sponse\022b\n\023GetTableDescriptors\022$.hbase.pb" +
@@ -75468,17 +75547,20 @@ public final class MasterProtos {
       "\n\033UpdateReplicationPeerConfig\022,.hbase.pb" +
       ".UpdateReplicationPeerConfigRequest\032-.hb" +
       "ase.pb.UpdateReplicationPeerConfigRespon",
-      "se\022t\n\031listDrainingRegionServers\022*.hbase." +
+      "se\022e\n\024ListReplicationPeers\022%.hbase.pb.Li" +
-      "pb.ListDrainingRegionServersRequest\032+.hb" +
+      "stReplicationPeersRequest\032&.hbase.pb.Lis" +
-      "ase.pb.ListDrainingRegionServersResponse" +
+      "tReplicationPeersResponse\022t\n\031listDrainin" +
-      "\022_\n\022drainRegionServers\022#.hbase.pb.DrainR" +
+      "gRegionServers\022*.hbase.pb.ListDrainingRe" +
-      "egionServersRequest\032$.hbase.pb.DrainRegi" +
+      "gionServersRequest\032+.hbase.pb.ListDraini" +
-      "onServersResponse\022}\n\034removeDrainFromRegi" +
+      "ngRegionServersResponse\022_\n\022drainRegionSe" +
-      "onServers\022-.hbase.pb.RemoveDrainFromRegi" +
+      "rvers\022#.hbase.pb.DrainRegionServersReque" +
-      "onServersRequest\032..hbase.pb.RemoveDrainF" +
+      "st\032$.hbase.pb.DrainRegionServersResponse" +
-      "romRegionServersResponseBI\n1org.apache.h" +
+      "\022}\n\034removeDrainFromRegionServers\022-.hbase" +
-      "adoop.hbase.shaded.protobuf.generatedB\014M",
+      ".pb.RemoveDrainFromRegionServersRequest\032",
-      "asterProtosH\001\210\001\001\240\001\001"
+      "..hbase.pb.RemoveDrainFromRegionServersR" +
+      "esponseBI\n1org.apache.hadoop.hbase.shade" +
+      "d.protobuf.generatedB\014MasterProtosH\001\210\001\001\240" +
+      "\001\001"
     };
     org.apache.hadoop.hbase.shaded.com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
         new org.apache.hadoop.hbase.shaded.com.google.protobuf.Descriptors.FileDescriptor.    InternalDescriptorAssigner() {

hbase-protocol-shaded/src/main/protobuf/Master.proto

@@ -893,6 +893,10 @@ service MasterService {
   rpc UpdateReplicationPeerConfig(UpdateReplicationPeerConfigRequest)
     returns(UpdateReplicationPeerConfigResponse);
 
+  /** Returns a list of replication peers */
+  rpc ListReplicationPeers(ListReplicationPeersRequest)
+    returns(ListReplicationPeersResponse);
+
   /** Returns a list of ServerNames marked as draining. */
   rpc listDrainingRegionServers(ListDrainingRegionServersRequest)
     returns(ListDrainingRegionServersResponse);

hbase-protocol-shaded/src/main/protobuf/Replication.proto

@@ -57,6 +57,15 @@ message ReplicationState {
   required State state = 1;
 }
 
+/**
+ * Used by replication. Description of the replication peer.
+ */
+message ReplicationPeerDescription {
+  required string id = 1;
+  required ReplicationState state = 2;
+  required ReplicationPeer config = 3;
+}
+
 /**
  * Used by replication. Holds the current position in an WAL file.
  */
@@ -109,3 +118,11 @@ message UpdateReplicationPeerConfigRequest {
 
 message UpdateReplicationPeerConfigResponse {
 }
+
+message ListReplicationPeersRequest {
+  optional string regex = 1;
+}
+
+message ListReplicationPeersResponse {
+  repeated ReplicationPeerDescription peer_desc = 1;
+}

hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/MasterObserver.java

@@ -1951,4 +1951,24 @@ public interface MasterObserver extends Coprocessor {
       final ObserverContext<MasterCoprocessorEnvironment> ctx, String peerId,
       ReplicationPeerConfig peerConfig) throws IOException {
   }
+
+  /**
+   * Called before list replication peers.
+   * @param ctx
+   * @param regex The regular expression to match peer id
+   * @throws IOException on failure
+   */
+  default void preListReplicationPeers(final ObserverContext<MasterCoprocessorEnvironment> ctx,
+      String regex) throws IOException {
+  }
+
+  /**
+   * Called after list replication peers.
+   * @param ctx
+   * @param regex The regular expression to match peer id
+   * @throws IOException on failure
+   */
+  default void postListReplicationPeers(final ObserverContext<MasterCoprocessorEnvironment> ctx,
+      String regex) throws IOException {
+  }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java

@@ -142,6 +142,7 @@ import org.apache.hadoop.hbase.regionserver.compactions.FIFOCompactionPolicy;
 import org.apache.hadoop.hbase.replication.ReplicationException;
 import org.apache.hadoop.hbase.replication.ReplicationFactory;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
+import org.apache.hadoop.hbase.replication.ReplicationPeerDescription;
 import org.apache.hadoop.hbase.replication.ReplicationQueuesZKImpl;
 import org.apache.hadoop.hbase.replication.master.TableCFsUpdater;
 import org.apache.hadoop.hbase.replication.regionserver.Replication;
@@ -3224,6 +3225,21 @@ public class HMaster extends HRegionServer implements MasterServices {
     }
   }
 
+  @Override
+  public List<ReplicationPeerDescription> listReplicationPeers(String regex)
+      throws ReplicationException, IOException {
+    if (cpHost != null) {
+      cpHost.preListReplicationPeers(regex);
+    }
+    LOG.info(getClientIdAuditPrefix() + " list replication peers, regex=" + regex);
+    Pattern pattern = regex == null ? null : Pattern.compile(regex);
+    List<ReplicationPeerDescription> peers = this.replicationManager.listReplicationPeers(pattern);
+    if (cpHost != null) {
+      cpHost.postListReplicationPeers(regex);
+    }
+    return peers;
+  }
+
   @Override
   public void drainRegionServer(final ServerName server) {
     String parentZnode = getZooKeeper().znodePaths.drainingZNode;

hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterCoprocessorHost.java

@@ -1769,4 +1769,24 @@ public class MasterCoprocessorHost
       }
     });
   }
+
+  public void preListReplicationPeers(final String regex) throws IOException {
+    execOperation(coprocessors.isEmpty() ? null : new CoprocessorOperation() {
+      @Override
+      public void call(MasterObserver observer, ObserverContext<MasterCoprocessorEnvironment> ctx)
+          throws IOException {
+        observer.preListReplicationPeers(ctx, regex);
+      }
+    });
+  }
+
+  public void postListReplicationPeers(final String regex) throws IOException {
+    execOperation(coprocessors.isEmpty() ? null : new CoprocessorOperation() {
+      @Override
+      public void call(MasterObserver observer, ObserverContext<MasterCoprocessorEnvironment> ctx)
+          throws IOException {
+        observer.postListReplicationPeers(ctx, regex);
+      }
+    });
+  }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java

@@ -95,6 +95,8 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.Enabl
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.EnableReplicationPeerResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.GetReplicationPeerConfigRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.GetReplicationPeerConfigResponse;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersRequest;
+import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.ListReplicationPeersResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.RemoveReplicationPeerRequest;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.RemoveReplicationPeerResponse;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.UpdateReplicationPeerConfigRequest;
@@ -102,6 +104,7 @@ import org.apache.hadoop.hbase.shaded.protobuf.generated.ReplicationProtos.Updat
 import org.apache.hadoop.hbase.regionserver.RSRpcServices;
 import org.apache.hadoop.hbase.replication.ReplicationException;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
+import org.apache.hadoop.hbase.replication.ReplicationPeerDescription;
 import org.apache.hadoop.hbase.security.User;
 import org.apache.hadoop.hbase.security.access.AccessController;
 import org.apache.hadoop.hbase.security.visibility.VisibilityController;
@@ -1727,6 +1730,22 @@ public class MasterRpcServices extends RSRpcServices
     }
   }
 
+  @Override
+  public ListReplicationPeersResponse listReplicationPeers(RpcController controller,
+      ListReplicationPeersRequest request) throws ServiceException {
+    ListReplicationPeersResponse.Builder response = ListReplicationPeersResponse.newBuilder();
+    try {
+      List<ReplicationPeerDescription> peers = master
+          .listReplicationPeers(request.hasRegex() ? request.getRegex() : null);
+      for (ReplicationPeerDescription peer : peers) {
+        response.addPeerDesc(ReplicationSerDeHelper.toProtoReplicationPeerDescription(peer));
+      }
+    } catch (ReplicationException | IOException e) {
+      throw new ServiceException(e);
+    }
+    return response.build();
+  }
+
   @Override
   public ListDrainingRegionServersResponse listDrainingRegionServers(RpcController controller,
       ListDrainingRegionServersRequest request) throws ServiceException {

hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterServices.java

@@ -42,6 +42,7 @@ import org.apache.hadoop.hbase.procedure2.ProcedureExecutor;
 import org.apache.hadoop.hbase.quotas.MasterQuotaManager;
 import org.apache.hadoop.hbase.replication.ReplicationException;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
+import org.apache.hadoop.hbase.replication.ReplicationPeerDescription;
 
 import com.google.protobuf.Service;
 
@@ -461,6 +462,14 @@ public interface MasterServices extends Server {
   void updateReplicationPeerConfig(String peerId, ReplicationPeerConfig peerConfig)
       throws ReplicationException, IOException;
 
+  /**
+   * Return a list of replication peers.
+   * @param regex The regular expression to match peer id
+   * @return a list of replication peers description
+   */
+  List<ReplicationPeerDescription> listReplicationPeers(String regex) throws ReplicationException,
+      IOException;
+
   /**
    * Mark a region server as draining to prevent additional regions from getting assigned to it.
    * @param server Region servers to drain.

hbase-server/src/main/java/org/apache/hadoop/hbase/master/replication/ReplicationManager.java

@@ -18,9 +18,12 @@
 package org.apache.hadoop.hbase.master.replication;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.regex.Pattern;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.Abortable;
@@ -30,6 +33,7 @@ import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.replication.ReplicationException;
 import org.apache.hadoop.hbase.replication.ReplicationFactory;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
+import org.apache.hadoop.hbase.replication.ReplicationPeerDescription;
 import org.apache.hadoop.hbase.replication.ReplicationPeers;
 import org.apache.hadoop.hbase.replication.ReplicationQueuesClient;
 import org.apache.hadoop.hbase.replication.ReplicationQueuesClientArguments;
@@ -100,6 +104,20 @@ public class ReplicationManager {
     this.replicationPeers.updatePeerConfig(peerId, peerConfig);
   }
 
+  public List<ReplicationPeerDescription> listReplicationPeers(Pattern pattern)
+      throws ReplicationException {
+    List<ReplicationPeerDescription> peers = new ArrayList<>();
+    List<String> peerIds = replicationPeers.getAllPeerIds();
+    for (String peerId : peerIds) {
+      if (pattern == null || (pattern != null && pattern.matcher(peerId).matches())) {
+        peers.add(new ReplicationPeerDescription(peerId, replicationPeers
+            .getStatusOfPeerFromBackingStore(peerId), replicationPeers
+            .getReplicationPeerConfig(peerId)));
+      }
+    }
+    return peers;
+  }
+
   /**
    * Set a namespace in the peer config means that all tables in this namespace
    * will be replicated to the peer cluster.

hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java

@@ -2733,4 +2733,10 @@ public class AccessController extends BaseMasterAndRegionObserver
       ReplicationPeerConfig peerConfig) throws IOException {
     requirePermission(getActiveUser(ctx), "updateReplicationPeerConfig", Action.ADMIN);
   }
-}
+
+  @Override
+  public void preListReplicationPeers(final ObserverContext<MasterCoprocessorEnvironment> ctx,
+      String regex) throws IOException {
+    requirePermission(getActiveUser(ctx), "listReplicationPeers", Action.ADMIN);
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/client/replication/TestReplicationAdmin.java

@@ -31,6 +31,7 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HConstants;
+import org.apache.hadoop.hbase.ReplicationPeerNotFoundException;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.RetriesExhaustedException;
 import org.apache.hadoop.hbase.replication.ReplicationException;
@@ -207,7 +208,7 @@ public class TestReplicationAdmin {
     assertFalse(admin.getPeerState(ID_ONE));
     try {
       admin.getPeerState(ID_SECOND);
-    } catch (IllegalArgumentException iae) {
+    } catch (ReplicationPeerNotFoundException e) {
       // OK!
     }
     admin.removePeer(ID_ONE);

hbase-server/src/test/java/org/apache/hadoop/hbase/master/MockNoopMasterServices.java

@@ -42,6 +42,7 @@ import org.apache.hadoop.hbase.procedure2.ProcedureExecutor;
 import org.apache.hadoop.hbase.quotas.MasterQuotaManager;
 import org.apache.hadoop.hbase.replication.ReplicationException;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
+import org.apache.hadoop.hbase.replication.ReplicationPeerDescription;
 import org.apache.hadoop.hbase.security.User;
 import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
 import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
@@ -425,4 +426,10 @@ public class MockNoopMasterServices implements MasterServices, Server {
   public void updateReplicationPeerConfig(String peerId, ReplicationPeerConfig peerConfig)
       throws ReplicationException, IOException {
   }
+
+  @Override
+  public List<ReplicationPeerDescription> listReplicationPeers(String regex)
+      throws ReplicationException, IOException {
+    return null;
+  }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/security/access/TestAccessController.java

@@ -2961,4 +2961,19 @@ public class TestAccessController extends SecureTestUtil {
     verifyAllowed(action, SUPERUSER, USER_ADMIN);
     verifyDenied(action, USER_CREATE, USER_RW, USER_RO, USER_NONE, USER_OWNER);
   }
+
+  @Test
+  public void testListReplicationPeers() throws Exception {
+    AccessTestAction action = new AccessTestAction() {
+      @Override
+      public Object run() throws Exception {
+        ACCESS_CONTROLLER.preListReplicationPeers(ObserverContext.createAndPrepare(CP_ENV, null),
+          "test");
+        return null;
+      }
+    };
+
+    verifyAllowed(action, SUPERUSER, USER_ADMIN);
+    verifyDenied(action, USER_CREATE, USER_RW, USER_RO, USER_NONE, USER_OWNER);
+  }
 }

src/main/asciidoc/_chapters/appendix_acl_matrix.adoc

@@ -122,6 +122,7 @@ In case the table goes out of date, the unit tests which check for accuracy of p
 |        | disableReplicationPeer | superuser\|global(A)
 |        | getReplicationPeerConfig | superuser\|global(A)
 |        | updateReplicationPeerConfig | superuser\|global(A)
+|        | listReplicationPeers | superuser\|global(A)
 | Region | openRegion | superuser\|global(A)
 |        | closeRegion | superuser\|global(A)
 |        | flush | superuser\|global(A)\|global\(C)\|TableOwner\|table(A)\|table\(C)