HBASE-19301 Provide way for CPs to create short circuited connection with custom configurations.

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

@@ -127,6 +127,7 @@ public final class ConnectionUtils {
    * localhost if the invocation target is 'this' server; save on network and protobuf
    * invocations.
    */
+  // TODO This has to still do PB marshalling/unmarshalling stuff. Check how/whether we can avoid.
   @VisibleForTesting // Class is visible so can assert we are short-circuiting when expected.
   public static class ShortCircuitingClusterConnection extends ConnectionImplementation {
     private final ServerName serverName;

hbase-server/src/main/java/org/apache/hadoop/hbase/Server.java

@@ -53,6 +53,8 @@ public interface Server extends Abortable, Stoppable {
    */
   Connection getConnection();
 
+  Connection createConnection(Configuration conf) throws IOException;
+
   /**
    * Returns a reference to the servers' cluster connection. Prefer {@link #getConnection()}.
    *

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

@@ -19,13 +19,16 @@
 
 package org.apache.hadoop.hbase.coprocessor;
 
-import org.apache.hadoop.hbase.ServerName;
-import org.apache.hadoop.hbase.client.Connection;
-import org.apache.yetus.audience.InterfaceAudience;
-import org.apache.yetus.audience.InterfaceStability;
+import java.io.IOException;
+
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.CoprocessorEnvironment;
 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
+import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.metrics.MetricRegistry;
+import org.apache.yetus.audience.InterfaceAudience;
+import org.apache.yetus.audience.InterfaceStability;
 
 @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
 @InterfaceStability.Evolving
@@ -41,15 +44,31 @@ public interface MasterCoprocessorEnvironment extends CoprocessorEnvironment<Mas
    * struggling or it is on the other side of a network partition. Any use of Connection from
    * inside a Coprocessor must be able to handle all such hiccups.
    *
-   * <p>Using a Connection to get at a local resource -- say a Region that is on the local
+   * <p>Using this Connection to get at a local resource -- say a Region that is on the local
    * Server or using Admin Interface from a Coprocessor hosted on the Master -- will result in a
-   * short-circuit of the RPC framework to make a direct invocation avoiding RPC (and
-   * protobuf marshalling/unmarshalling).
-   *
+   * short-circuit of the RPC framework to make a direct invocation avoiding RPC.
+   * <p>
+   * Note: If you want to create Connection with your own Configuration and NOT use the Master's
+   * Connection (though its cache of locations will be warm, and its life-cycle is not the concern
+   * of the CP), see {@link #createConnection(Configuration)}.
    * @return The host's Connection to the Cluster.
    */
   Connection getConnection();
 
+  /**
+   * Creates a cluster connection using the passed configuration.
+   * <p>Using this Connection to get at a local resource -- say a Region that is on the local
+   * Server or using Admin Interface from a Coprocessor hosted on the Master -- will result in a
+   * short-circuit of the RPC framework to make a direct invocation avoiding RPC.
+   * <p>
+   * Note: HBase will NOT cache/maintain this Connection. If Coprocessors need to cache and reuse
+   * this connection, it has to be done by Coprocessors. Also make sure to close it after use.
+   *
+   * @param conf configuration
+   * @return Connection created using the passed conf.
+   */
+  Connection createConnection(Configuration conf) throws IOException;
+
   /**
    * Returns a MetricRegistry that can be used to track metrics at the master level.
    *

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

@@ -19,8 +19,10 @@
 
 package org.apache.hadoop.hbase.coprocessor;
 
+import java.io.IOException;
 import java.util.concurrent.ConcurrentMap;
 
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.CoprocessorEnvironment;
 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
 import org.apache.hadoop.hbase.ServerName;
@@ -62,13 +64,29 @@ public interface RegionCoprocessorEnvironment extends CoprocessorEnvironment<Reg
    *
    * <p>Using a Connection to get at a local resource -- say a Region that is on the local
    * Server or using Admin Interface from a Coprocessor hosted on the Master -- will result in a
-   * short-circuit of the RPC framework to make a direct invocation avoiding RPC (and
-   * protobuf marshalling/unmarshalling).
-   *
+   * short-circuit of the RPC framework to make a direct invocation avoiding RPC.
+   *<p>
+   * Note: If you want to create Connection with your own Configuration and NOT use the RegionServer
+   * Connection (though its cache of locations will be warm, and its life-cycle is not the concern
+   * of the CP), see {@link #createConnection(Configuration)}.
    * @return The host's Connection to the Cluster.
    */
   Connection getConnection();
 
+  /**
+   * Creates a cluster connection using the passed configuration.
+   * <p>Using this Connection to get at a local resource -- say a Region that is on the local
+   * Server or using Admin Interface from a Coprocessor hosted on the Master -- will result in a
+   * short-circuit of the RPC framework to make a direct invocation avoiding RPC.
+   * <p>
+   * Note: HBase will NOT cache/maintain this Connection. If Coprocessors need to cache and reuse
+   * this connection, it has to be done by Coprocessors. Also make sure to close it after use.
+   *
+   * @param conf configuration
+   * @return Connection created using the passed conf.
+   */
+  Connection createConnection(Configuration conf) throws IOException;
+
   /**
    * Returns a MetricRegistry that can be used to track metrics at the region server level. All
    * metrics tracked at this level will be shared by all the coprocessor instances

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

@@ -18,6 +18,9 @@
  */
 package org.apache.hadoop.hbase.coprocessor;
 
+import java.io.IOException;
+
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.CoprocessorEnvironment;
 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
 import org.apache.hadoop.hbase.ServerName;
@@ -49,13 +52,29 @@ public interface RegionServerCoprocessorEnvironment
    *
    * <p>Using a Connection to get at a local resource -- say a Region that is on the local
    * Server or using Admin Interface from a Coprocessor hosted on the Master -- will result in a
-   * short-circuit of the RPC framework to make a direct invocation avoiding RPC (and
-   * protobuf marshalling/unmarshalling).
-   *
+   * short-circuit of the RPC framework to make a direct invocation avoiding RPC.
+   *<p>
+   * Note: If you want to create Connection with your own Configuration and NOT use the RegionServer
+   * Connection (though its cache of locations will be warm, and its life-cycle is not the concern
+   * of the CP), see {@link #createConnection(Configuration)}.
    * @return The host's Connection to the Cluster.
    */
   Connection getConnection();
 
+  /**
+   * Creates a cluster connection using the passed configuration.
+   * <p>Using this Connection to get at a local resource -- say a Region that is on the local
+   * Server or using Admin Interface from a Coprocessor hosted on the Master -- will result in a
+   * short-circuit of the RPC framework to make a direct invocation avoiding RPC.
+   * <p>
+   * Note: HBase will NOT cache/maintain this Connection. If Coprocessors need to cache and reuse
+   * this connection, it has to be done by Coprocessors. Also make sure to close it after use.
+   *
+   * @param conf configuration
+   * @return Connection created using the passed conf.
+   */
+  Connection createConnection(Configuration conf) throws IOException;
+
   /**
    * Returns a MetricRegistry that can be used to track metrics at the region server level.
    *

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

@@ -78,16 +78,14 @@ public class MasterCoprocessorHost
    */
   private static class MasterEnvironment extends BaseEnvironment<MasterCoprocessor>
       implements MasterCoprocessorEnvironment {
-    private final Connection connection;
-    private final ServerName serverName;
     private final boolean supportGroupCPs;
     private final MetricRegistry metricRegistry;
+    private final MasterServices services;
 
     public MasterEnvironment(final MasterCoprocessor impl, final int priority, final int seq,
         final Configuration conf, final MasterServices services) {
       super(impl, priority, seq, conf);
-      this.connection = services.getConnection();
-      this.serverName = services.getServerName();
+      this.services = services;
       supportGroupCPs = !useLegacyMethod(impl.getClass(),
           "preBalanceRSGroup", ObserverContext.class, String.class);
       this.metricRegistry =
@@ -96,12 +94,17 @@ public class MasterCoprocessorHost
 
     @Override
     public ServerName getServerName() {
-      return this.serverName;
+      return this.services.getServerName();
     }
 
     @Override
     public Connection getConnection() {
-      return this.connection;
+      return this.services.getConnection();
+    }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return this.services.createConnection(conf);
     }
 
     @Override

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java

@@ -3715,4 +3715,11 @@ public class HRegionServer extends HasThread implements
   public NettyEventLoopGroupConfig getEventLoopGroupConfig() {
     return eventLoopGroupConfig;
   }
+
+  @Override
+  public Connection createConnection(Configuration conf) throws IOException {
+    User user = UserProvider.instantiate(conf).getCurrent();
+    return ConnectionUtils.createShortCircuitConnection(conf, null, user, this.serverName,
+        this.rpcServices, this.rpcServices);
+  }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/RegionCoprocessorHost.java

@@ -114,9 +114,7 @@ public class RegionCoprocessorHost
     private Region region;
     ConcurrentMap<String, Object> sharedData;
     private final MetricRegistry metricRegistry;
-    private final Connection connection;
-    private final ServerName serverName;
-    private final OnlineRegions onlineRegions;
+    private final RegionServerServices services;
 
     /**
      * Constructor
@@ -128,11 +126,8 @@ public class RegionCoprocessorHost
         final RegionServerServices services, final ConcurrentMap<String, Object> sharedData) {
       super(impl, priority, seq, conf);
       this.region = region;
-      // Mocks may have services as null at test time.
-      this.connection = services != null? services.getConnection(): null;
-      this.serverName = services != null? services.getServerName(): null;
       this.sharedData = sharedData;
-      this.onlineRegions = services;
+      this.services = services;
       this.metricRegistry =
           MetricsCoprocessor.createRegistryForRegionCoprocessor(impl.getClass().getName());
     }
@@ -144,17 +139,23 @@ public class RegionCoprocessorHost
     }
 
     public OnlineRegions getOnlineRegions() {
-      return this.onlineRegions;
+      return this.services;
     }
 
     @Override
     public Connection getConnection() {
-      return this.connection;
+      // Mocks may have services as null at test time.
+      return services != null ? services.getConnection() : null;
+    }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return services != null ? this.services.createConnection(conf) : null;
     }
 
     @Override
     public ServerName getServerName() {
-      return this.serverName;
+      return services != null? services.getServerName(): null;
     }
 
     @Override

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/RegionServerCoprocessorHost.java

@@ -210,9 +210,7 @@ public class RegionServerCoprocessorHost extends
   private static class RegionServerEnvironment extends BaseEnvironment<RegionServerCoprocessor>
       implements RegionServerCoprocessorEnvironment {
     private final MetricRegistry metricRegistry;
-    private final Connection connection;
-    private final ServerName serverName;
-    private final OnlineRegions onlineRegions;
+    private final RegionServerServices services;
 
     @edu.umd.cs.findbugs.annotations.SuppressWarnings(value="BC_UNCONFIRMED_CAST",
         justification="Intentional; FB has trouble detecting isAssignableFrom")
@@ -223,26 +221,29 @@ public class RegionServerCoprocessorHost extends
       for (Service service : impl.getServices()) {
         services.registerService(service);
       }
-      this.onlineRegions = services;
-      this.connection = services.getConnection();
-      this.serverName = services.getServerName();
+      this.services = services;
       this.metricRegistry =
           MetricsCoprocessor.createRegistryForRSCoprocessor(impl.getClass().getName());
     }
 
     @Override
     public OnlineRegions getOnlineRegions() {
-      return this.onlineRegions;
+      return this.services;
     }
 
     @Override
     public ServerName getServerName() {
-      return this.serverName;
+      return this.services.getServerName();
     }
 
     @Override
     public Connection getConnection() {
-      return this.connection;
+      return this.services.getConnection();
+    }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return this.services.createConnection(conf);
     }
 
     @Override

hbase-server/src/main/java/org/apache/hadoop/hbase/replication/regionserver/ReplicationSyncUp.java

@@ -17,6 +17,8 @@
  */
 package org.apache.hadoop.hbase.replication.regionserver;
 
+import java.io.IOException;
+
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
@@ -31,6 +33,7 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.util.FSUtils;
 import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
 import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
@@ -203,5 +206,10 @@ public class ReplicationSyncUp extends Configured implements Tool {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/MockRegionServerServices.java

@@ -31,6 +31,7 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.locking.EntityLock;
 import org.apache.hadoop.hbase.executor.ExecutorService;
@@ -329,4 +330,9 @@ public class MockRegionServerServices implements RegionServerServices {
   public RegionServerSpaceQuotaManager getRegionServerSpaceQuotaManager() {
     return null;
   }
+
+  @Override
+  public Connection createConnection(Configuration conf) throws IOException {
+    return null;
+  }
 }

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

@@ -32,6 +32,7 @@ import org.apache.hadoop.hbase.TableDescriptors;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.ClusterConnection;
 import org.apache.hadoop.hbase.client.ColumnFamilyDescriptor;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.MasterSwitchType;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.TableDescriptor;
@@ -460,4 +461,9 @@ public class MockNoopMasterServices implements MasterServices, Server {
   public FileSystem getFileSystem() {
     return null;
   }
+
+  @Override
+  public Connection createConnection(Configuration conf) throws IOException {
+    return null;
+  }
 }

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

@@ -39,6 +39,7 @@ import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.ZooKeeperConnectionException;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.RegionInfoBuilder;
 import org.apache.hadoop.hbase.client.Result;
@@ -672,4 +673,9 @@ ClientProtos.ClientService.BlockingInterface, RegionServerServices {
       throws ServiceException {
     return null;
   }
+
+  @Override
+  public Connection createConnection(Configuration conf) throws IOException {
+    return null;
+  }
 }

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

@@ -35,6 +35,7 @@ import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.monitoring.MonitoredTask;
 import org.apache.hadoop.hbase.testclassification.MasterTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
@@ -343,5 +344,10 @@ public class TestActiveMasterManager {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 }

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

@@ -39,6 +39,7 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.testclassification.MasterTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.util.EnvironmentEdge;
@@ -272,6 +273,11 @@ public class TestHFileCleaner {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 
   @Test

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

@@ -36,6 +36,7 @@ import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.io.HFileLink;
 import org.apache.hadoop.hbase.testclassification.MasterTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
@@ -211,5 +212,10 @@ public class TestHFileLinkCleaner {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 }

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

@@ -47,6 +47,7 @@ import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.Waiter;
 import org.apache.hadoop.hbase.ZooKeeperConnectionException;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.replication.ReplicationFactory;
 import org.apache.hadoop.hbase.replication.ReplicationQueues;
 import org.apache.hadoop.hbase.replication.ReplicationQueuesArguments;
@@ -319,6 +320,11 @@ public class TestLogsCleaner {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 
   static class FaultyZooKeeperWatcher extends ZKWatcher {

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

@@ -40,6 +40,7 @@ import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.ZooKeeperConnectionException;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.replication.ReplicationException;
 import org.apache.hadoop.hbase.replication.ReplicationFactory;
 import org.apache.hadoop.hbase.replication.ReplicationPeerConfig;
@@ -330,6 +331,11 @@ public class TestReplicationHFileCleaner {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 
   static class FaultyZooKeeperWatcher extends ZKWatcher {

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestHeapMemoryManager.java

@@ -23,6 +23,7 @@ import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import java.io.IOException;
 import java.lang.management.ManagementFactory;
 import java.util.Iterator;
 
@@ -37,6 +38,7 @@ import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.Waiter;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.io.hfile.BlockCache;
 import org.apache.hadoop.hbase.io.hfile.BlockCacheKey;
 import org.apache.hadoop.hbase.io.hfile.CacheStats;
@@ -857,6 +859,11 @@ public class TestHeapMemoryManager {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 
   static class CustomHeapMemoryTuner implements HeapMemoryTuner {

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestSplitLogWorker.java

@@ -26,6 +26,7 @@ import static org.junit.Assert.assertTrue;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
+import java.io.IOException;
 import java.util.List;
 import java.util.concurrent.atomic.LongAdder;
 
@@ -43,6 +44,7 @@ import org.apache.hadoop.hbase.SplitLogCounters;
 import org.apache.hadoop.hbase.SplitLogTask;
 import org.apache.hadoop.hbase.Waiter;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.coordination.ZkCoordinatedStateManager;
 import org.apache.hadoop.hbase.executor.ExecutorService;
 import org.apache.hadoop.hbase.executor.ExecutorType;
@@ -157,6 +159,11 @@ public class TestSplitLogWorker {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 
   private void waitForCounter(LongAdder ctr, long oldval, long newval, long timems)

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestWALLockup.java

@@ -41,6 +41,7 @@ import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.Durability;
 import org.apache.hadoop.hbase.client.Put;
 import org.apache.hadoop.hbase.regionserver.wal.DamagedWALException;
@@ -569,6 +570,11 @@ public class TestWALLockup {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 
   static class DummyWALActionsListener extends WALActionsListener.Base {

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

@@ -26,6 +26,7 @@ import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.testclassification.ReplicationTests;
 import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
@@ -485,5 +486,10 @@ public class TestReplicationStateHBaseImpl {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 }

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

@@ -35,6 +35,7 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.testclassification.ReplicationTests;
 import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
@@ -217,5 +218,10 @@ public class TestReplicationStateZKImpl extends TestReplicationStateBasic {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 }

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

@@ -22,6 +22,7 @@ import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -38,6 +39,7 @@ import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
 import org.apache.hadoop.hbase.testclassification.ReplicationTests;
 import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
@@ -317,5 +319,10 @@ public class TestReplicationTrackerZKImpl {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/replication/regionserver/TestReplicationSourceManager.java

@@ -60,6 +60,7 @@ import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Waiter;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.regionserver.MultiVersionConcurrencyControl;
 import org.apache.hadoop.hbase.regionserver.wal.WALActionsListener;
 import org.apache.hadoop.hbase.wal.WALEdit;
@@ -731,5 +732,10 @@ public abstract class TestReplicationSourceManager {
     public boolean isStopping() {
       return false;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/security/token/TestTokenAuthentication.java

@@ -323,6 +323,11 @@ public class TestTokenAuthentication {
         public Connection getConnection() {
           return null;
         }
+
+        @Override
+        public Connection createConnection(Configuration conf) throws IOException {
+          return null;
+        }
       });
 
       started = true;
@@ -410,6 +415,11 @@ public class TestTokenAuthentication {
       // TODO Auto-generated method stub
       return null;
     }
+
+    @Override
+    public Connection createConnection(Configuration conf) throws IOException {
+      return null;
+    }
   }
 
   @Parameters(name = "{index}: rpcServerImpl={0}")

hbase-server/src/test/java/org/apache/hadoop/hbase/util/MockServer.java

@@ -30,6 +30,7 @@ import org.apache.hadoop.hbase.Server;
 import org.apache.hadoop.hbase.ServerName;
 import org.apache.hadoop.hbase.ZooKeeperConnectionException;
 import org.apache.hadoop.hbase.client.ClusterConnection;
+import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.zookeeper.MetaTableLocator;
 import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
 
@@ -144,4 +145,9 @@ public class MockServer implements Server {
   public boolean isStopping() {
     return false;
   }
+
+  @Override
+  public Connection createConnection(Configuration conf) throws IOException {
+    return null;
+  }
 }