diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptorBuilder.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptorBuilder.java
index bb302dbc856..20706c69549 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptorBuilder.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/client/ColumnFamilyDescriptorBuilder.java
@@ -1091,12 +1091,13 @@ public class ColumnFamilyDescriptorBuilder {
         s.append(HConstants.METADATA).append(" => ");
         s.append('{');
         boolean printComma = false;
-        for (Bytes k : values.keySet()) {
+        for (Map.Entry<Bytes, Bytes> entry : values.entrySet()) {
+          Bytes k = entry.getKey();
           if (RESERVED_KEYWORDS.contains(k)) {
             continue;
           }
           String key = Bytes.toString(k.get());
-          String value = Bytes.toStringBinary(values.get(k).get());
+          String value = Bytes.toStringBinary(entry.getValue().get());
           if (printComma) {
             s.append(", ");
           }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java
index d414f7036bc..2acddda401c 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/AbstractRpcClient.java
@@ -101,6 +101,8 @@ public abstract class AbstractRpcClient<T extends RpcConnection> implements RpcC
   private static final ScheduledExecutorService IDLE_CONN_SWEEPER = Executors
       .newScheduledThreadPool(1, Threads.newDaemonThreadFactory("Idle-Rpc-Conn-Sweeper"));
 
+  @edu.umd.cs.findbugs.annotations.SuppressWarnings(value="MS_MUTABLE_COLLECTION_PKGPROTECT",
+      justification="the rest of the system which live in the different package can use")
   protected final static Map<Kind, TokenSelector<? extends TokenIdentifier>> TOKEN_HANDLERS = new HashMap<>();
 
   static {
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java
index eebe4bdb12f..b1b52b1a95c 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java
@@ -3211,7 +3211,6 @@ public final class ProtobufUtil {
       for (ServerName serverName : status.getServers()) {
         LiveServerInfo.Builder lsi =
             LiveServerInfo.newBuilder().setServer(ProtobufUtil.toServerName(serverName));
-        status.getLoad(serverName);
         lsi.setServerLoad(status.getLoad(serverName).obtainServerLoadPB());
         builder.addLiveServers(lsi.build());
       }
diff --git a/hbase-client/src/main/java/org/apache/hadoop/hbase/util/PoolMap.java b/hbase-client/src/main/java/org/apache/hadoop/hbase/util/PoolMap.java
index 2131db359f4..40c6b55e534 100644
--- a/hbase-client/src/main/java/org/apache/hadoop/hbase/util/PoolMap.java
+++ b/hbase-client/src/main/java/org/apache/hadoop/hbase/util/PoolMap.java
@@ -210,7 +210,7 @@ public class PoolMap<K, V> implements Map<K, V> {
         }
       }
     }
-    return null;
+    return entries;
   }
 
   protected interface Pool<R> {