/*
    *
    * 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.client;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertNull;
  import static org.junit.Assert.assertTrue;
  import static org.junit.Assert.fail;
  import com.google.common.collect.Lists;
  
  import java.io.IOException;
  import java.lang.reflect.Field;
  import java.lang.reflect.Modifier;
  import java.net.SocketTimeoutException;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Random;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.SynchronousQueue;
  import java.util.concurrent.ThreadPoolExecutor;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicBoolean;
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.concurrent.atomic.AtomicLong;
  import java.util.concurrent.atomic.AtomicReference;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.CategoryBasedTimeout;
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.HBaseConfiguration;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.HRegionLocation;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.RegionLocations;
  import org.apache.hadoop.hbase.ServerName;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.Waiter;
  import org.apache.hadoop.hbase.client.ConnectionManager.HConnectionImplementation;
  import org.apache.hadoop.hbase.coprocessor.BaseRegionObserver;
  import org.apache.hadoop.hbase.coprocessor.ObserverContext;
  import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
  import org.apache.hadoop.hbase.exceptions.ClientExceptionsUtil;
  import org.apache.hadoop.hbase.exceptions.DeserializationException;
  import org.apache.hadoop.hbase.exceptions.RegionMovedException;
  import org.apache.hadoop.hbase.filter.Filter;
  import org.apache.hadoop.hbase.filter.FilterBase;
  import org.apache.hadoop.hbase.ipc.CallTimeoutException;
  import org.apache.hadoop.hbase.ipc.RpcClient;
  import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
  import org.apache.hadoop.hbase.master.HMaster;
  import org.apache.hadoop.hbase.regionserver.HRegionServer;
  import org.apache.hadoop.hbase.regionserver.Region;
  import org.apache.hadoop.hbase.regionserver.RegionServerStoppedException;
  import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
  import org.apache.hadoop.hbase.testclassification.LargeTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
  import org.apache.hadoop.hbase.util.JVMClusterUtil;
  import org.apache.hadoop.hbase.util.ManualEnvironmentEdge;
  import org.apache.hadoop.hbase.util.Threads;
  import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
  import org.junit.AfterClass;
  import org.junit.Assert;
  import org.junit.BeforeClass;
  import org.junit.Ignore;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  import org.junit.rules.TestRule;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertNull;
  import static org.junit.Assert.assertTrue;
  import static org.junit.Assert.fail;
 
 /**
  * This class is for testing HBaseConnectionManager features
  */
 @Category({LargeTests.class})
 public class TestHCM {
   @Rule public final TestRule timeout = CategoryBasedTimeout.builder()
       .withTimeout(this.getClass())
       .withLookingForStuckThread(true)
       .build();
   private static final Log LOG = LogFactory.getLog(TestHCM.class);
   private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
   private static final TableName TABLE_NAME =
       TableName.valueOf("test");
   private static final TableName TABLE_NAME1 =
       TableName.valueOf("test1");
   private static final TableName TABLE_NAME2 =
       TableName.valueOf("test2");
   private static final TableName TABLE_NAME3 =
       TableName.valueOf("test3");
   private static final TableName TABLE_NAME4 =
       TableName.valueOf("test4");
   private static final byte[] FAM_NAM = Bytes.toBytes("f");
   private static final byte[] ROW = Bytes.toBytes("bbb");
   private static final byte[] ROW_X = Bytes.toBytes("xxx");
   private static Random _randy = new Random();
   private static final int RPC_RETRY = 5;
 
 /**
 * This copro sleeps 20 second. The first call it fails. The second time, it works.
 */
   public static class SleepAndFailFirstTime extends BaseRegionObserver {
   static final AtomicLong ct = new AtomicLong(0);
   static final String SLEEP_TIME_CONF_KEY =
       "hbase.coprocessor.SleepAndFailFirstTime.sleepTime";
   static final long DEFAULT_SLEEP_TIME = 20000;
   static final AtomicLong sleepTime = new AtomicLong(DEFAULT_SLEEP_TIME);
 
   public SleepAndFailFirstTime() {
   }
 
     @Override
     public void postOpen(ObserverContext<RegionCoprocessorEnvironment> c) {
       RegionCoprocessorEnvironment env = c.getEnvironment();
       Configuration conf = env.getConfiguration();
       sleepTime.set(conf.getLong(SLEEP_TIME_CONF_KEY, DEFAULT_SLEEP_TIME));
     }
 
     @Override
     public void preGetOp(final ObserverContext<RegionCoprocessorEnvironment> e,
         final Get get, final List<Cell> results) throws IOException {
       Threads.sleep(sleepTime.get());
       if (ct.incrementAndGet() == 1) {
         throw new IOException("first call I fail");
       }
     }
 
     @Override
     public void prePut(final ObserverContext<RegionCoprocessorEnvironment> e,
         final Put put, final WALEdit edit, final Durability durability) throws IOException {
       Threads.sleep(sleepTime.get());
       if (ct.incrementAndGet() == 1) {
         throw new IOException("first call I fail");
       }
     }
 
     @Override
     public void preDelete(final ObserverContext<RegionCoprocessorEnvironment> e,
         final Delete delete,
         final WALEdit edit, final Durability durability) throws IOException {
       Threads.sleep(sleepTime.get());
       if (ct.incrementAndGet() == 1) {
         throw new IOException("first call I fail");
       }
     }
 
     @Override
     public Result preIncrement(final ObserverContext<RegionCoprocessorEnvironment> e,
         final Increment increment) throws IOException {
       Threads.sleep(sleepTime.get());
       if (ct.incrementAndGet() == 1) {
         throw new IOException("first call I fail");
       }
       return super.preIncrement(e, increment);
     }
 
   }
 
   public static class SleepCoprocessor extends BaseRegionObserver {
     public static final int SLEEP_TIME = 5000;
     @Override
     public void preGetOp(final ObserverContext<RegionCoprocessorEnvironment> e,
         final Get get, final List<Cell> results) throws IOException {
       Threads.sleep(SLEEP_TIME);
     }
 
     @Override
     public Result preIncrement(final ObserverContext<RegionCoprocessorEnvironment> e,
         final Increment increment) throws IOException {
       Threads.sleep(SLEEP_TIME);
       return super.preIncrement(e, increment);
     }
 
     @Override
     public void preDelete(final ObserverContext<RegionCoprocessorEnvironment> e, final Delete delete,
         final WALEdit edit, final Durability durability) throws IOException {
       Threads.sleep(SLEEP_TIME);
     }
 
     @Override
     public void prePut(final ObserverContext<RegionCoprocessorEnvironment> e,
         final Put put, final WALEdit edit, final Durability durability) throws IOException {
       Threads.sleep(SLEEP_TIME);
     }
 
   }
 
   public static class SleepLongerAtFirstCoprocessor extends BaseRegionObserver {
     public static final int SLEEP_TIME = 2000;
     static final AtomicLong ct = new AtomicLong(0);
 
     @Override
     public void preGetOp(final ObserverContext<RegionCoprocessorEnvironment> e,
         final Get get, final List<Cell> results) throws IOException {
       // After first sleep, all requests are timeout except the last retry. If we handle
       // all the following requests, finally the last request is also timeout. If we drop all
       // timeout requests, we can handle the last request immediately and it will not timeout.
       if (ct.incrementAndGet() <= 1) {
         Threads.sleep(SLEEP_TIME * (RPC_RETRY-1) * 2);
       } else {
         Threads.sleep(SLEEP_TIME);
       }
     }
   }
 
   @BeforeClass
   public static void setUpBeforeClass() throws Exception {
     TEST_UTIL.getConfiguration().setBoolean(HConstants.STATUS_PUBLISHED, true);
     // Up the handlers; this test needs more than usual.
     TEST_UTIL.getConfiguration().setInt(HConstants.REGION_SERVER_HIGH_PRIORITY_HANDLER_COUNT, 10);
     TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, RPC_RETRY);
     // simulate queue blocking in testDropTimeoutRequest
     TEST_UTIL.getConfiguration().setInt(HConstants.REGION_SERVER_HANDLER_COUNT, 1);
     TEST_UTIL.startMiniCluster(2);
   }
 
   @AfterClass public static void tearDownAfterClass() throws Exception {
     TEST_UTIL.shutdownMiniCluster();
   }
 
 
   private static int getHConnectionManagerCacheSize(){
     return HConnectionTestingUtility.getConnectionCount();
   }
 
   @Test
   public void testClusterConnection() throws IOException {
     ThreadPoolExecutor otherPool = new ThreadPoolExecutor(1, 1,
         5, TimeUnit.SECONDS,
         new SynchronousQueue<Runnable>(),
         Threads.newDaemonThreadFactory("test-hcm"));
 
     HConnection con1 = HConnectionManager.createConnection(TEST_UTIL.getConfiguration());
     HConnection con2 = HConnectionManager.createConnection(TEST_UTIL.getConfiguration(), otherPool);
     // make sure the internally created ExecutorService is the one passed
     assertTrue(otherPool == ((HConnectionImplementation)con2).getCurrentBatchPool());
 
     String tableName = "testClusterConnection";
     TEST_UTIL.createTable(tableName.getBytes(), FAM_NAM).close();
     HTable t = (HTable)con1.getTable(tableName, otherPool);
     // make sure passing a pool to the getTable does not trigger creation of an internal pool
     assertNull("Internal Thread pool should be null", ((HConnectionImplementation)con1).getCurrentBatchPool());
     // table should use the pool passed
     assertTrue(otherPool == t.getPool());
     t.close();
 
     t = (HTable)con2.getTable(tableName);
     // table should use the connectin's internal pool
     assertTrue(otherPool == t.getPool());
     t.close();
 
     t = (HTable)con2.getTable(Bytes.toBytes(tableName));
     // try other API too
     assertTrue(otherPool == t.getPool());
     t.close();
 
     t = (HTable)con2.getTable(TableName.valueOf(tableName));
     // try other API too
     assertTrue(otherPool == t.getPool());
     t.close();
 
     t = (HTable)con1.getTable(tableName);
     ExecutorService pool = ((HConnectionImplementation)con1).getCurrentBatchPool();
     // make sure an internal pool was created
     assertNotNull("An internal Thread pool should have been created", pool);
     // and that the table is using it
     assertTrue(t.getPool() == pool);
     t.close();
 
     t = (HTable)con1.getTable(tableName);
     // still using the *same* internal pool
     assertTrue(t.getPool() == pool);
     t.close();
 
     con1.close();
     // if the pool was created on demand it should be closed upon connection close
     assertTrue(pool.isShutdown());
 
     con2.close();
     // if the pool is passed, it is not closed
     assertFalse(otherPool.isShutdown());
     otherPool.shutdownNow();
   }
 
   /**
    * Naive test to check that HConnection#getAdmin returns a properly constructed HBaseAdmin object
    * @throws IOException Unable to construct admin
    */
   @Test
   public void testAdminFactory() throws IOException {
     Connection con1 = ConnectionFactory.createConnection(TEST_UTIL.getConfiguration());
     Admin admin = con1.getAdmin();
     assertTrue(admin.getConnection() == con1);
     assertTrue(admin.getConfiguration() == TEST_UTIL.getConfiguration());
     con1.close();
   }
 
   // Fails too often!  Needs work.  HBASE-12558
   @Ignore @Test (expected = RegionServerStoppedException.class)
   public void testClusterStatus() throws Exception {
 
     TableName tn =
         TableName.valueOf("testClusterStatus");
     byte[] cf = "cf".getBytes();
     byte[] rk = "rk1".getBytes();
 
     JVMClusterUtil.RegionServerThread rs = TEST_UTIL.getHBaseCluster().startRegionServer();
     rs.waitForServerOnline();
     final ServerName sn = rs.getRegionServer().getServerName();
 
     HTable t = TEST_UTIL.createTable(tn, cf);
     TEST_UTIL.waitTableAvailable(tn);
     TEST_UTIL.waitUntilNoRegionsInTransition();
 
     final HConnectionImplementation hci =  (HConnectionImplementation)t.getConnection();
     while (t.getRegionLocation(rk).getPort() != sn.getPort()){
       TEST_UTIL.getHBaseAdmin().move(t.getRegionLocation(rk).getRegionInfo().
           getEncodedNameAsBytes(), Bytes.toBytes(sn.toString()));
       TEST_UTIL.waitUntilNoRegionsInTransition();
       hci.clearRegionCache(tn);
     }
     Assert.assertNotNull(hci.clusterStatusListener);
     TEST_UTIL.assertRegionOnServer(t.getRegionLocation(rk).getRegionInfo(), sn, 20000);
 
     Put p1 = new Put(rk);
     p1.add(cf, "qual".getBytes(), "val".getBytes());
     t.put(p1);
 
     rs.getRegionServer().abort("I'm dead");
 
     // We want the status to be updated. That's a least 10 second
     TEST_UTIL.waitFor(40000, 1000, true, new Waiter.Predicate<Exception>() {
       @Override
       public boolean evaluate() throws Exception {
         return TEST_UTIL.getHBaseCluster().getMaster().getServerManager().
             getDeadServers().isDeadServer(sn);
       }
     });
 
     TEST_UTIL.waitFor(40000, 1000, true, new Waiter.Predicate<Exception>() {
       @Override
       public boolean evaluate() throws Exception {
         return hci.clusterStatusListener.isDeadServer(sn);
       }
     });
 
     t.close();
     hci.getClient(sn);  // will throw an exception: RegionServerStoppedException
   }
 
   /**
    * Test that we can handle connection close: it will trigger a retry, but the calls will
    *  finish.
    */
   @Test
   public void testConnectionCloseAllowsInterrupt() throws Exception {
     testConnectionClose(true);
   }
 
   @Test
   public void testConnectionNotAllowsInterrupt() throws Exception {
     testConnectionClose(false);
   }
 
   /**
    * Test that an operation can fail if we read the global operation timeout, even if the
    * individual timeout is fine. We do that with:
    * - client side: an operation timeout of 30 seconds
    * - server side: we sleep 20 second at each attempt. The first work fails, the second one
    * succeeds. But the client won't wait that much, because 20 + 20 > 30, so the client
    * timeouted when the server answers.
    */
   @Test
   public void testGetOperationTimeout() throws Exception {
     HTableDescriptor hdt = TEST_UTIL.createTableDescriptor("HCM-testGetOperationTimeout");
     hdt.addCoprocessor(SleepAndFailFirstTime.class.getName());
     Table table = TEST_UTIL.createTable(hdt, new byte[][]{FAM_NAM}, TEST_UTIL.getConfiguration());
     table.setRpcTimeout(Integer.MAX_VALUE);
     SleepAndFailFirstTime.ct.set(0);
     // Check that it works if the timeout is big enough
     table.setOperationTimeout(120 * 1000);
     table.get(new Get(FAM_NAM));
 
     // Resetting and retrying. Will fail this time, not enough time for the second try
     SleepAndFailFirstTime.ct.set(0);
     try {
       table.setOperationTimeout(30 * 1000);
       table.get(new Get(FAM_NAM));
       Assert.fail("We expect an exception here");
     } catch (SocketTimeoutException e) {
       // The client has a CallTimeout class, but it's not shared.We're not very clean today,
       //  in the general case you can expect the call to stop, but the exception may vary.
       // In this test however, we're sure that it will be a socket timeout.
       LOG.info("We received an exception, as expected ", e);
     } catch (IOException e) {
       Assert.fail("Wrong exception:" + e.getMessage());
     } finally {
       table.close();
     }
   }
 
   @Test
   public void testPutOperationTimeout() throws Exception {
     HTableDescriptor hdt = TEST_UTIL.createTableDescriptor("HCM-testPutOperationTimeout");
     hdt.addCoprocessor(SleepAndFailFirstTime.class.getName());
     Table table = TEST_UTIL.createTable(hdt, new byte[][] { FAM_NAM },TEST_UTIL.getConfiguration());
     table.setRpcTimeout(Integer.MAX_VALUE);
     SleepAndFailFirstTime.ct.set(0);
     // Check that it works if the timeout is big enough
     table.setOperationTimeout(120 * 1000);
     table.put(new Put(FAM_NAM).addColumn(FAM_NAM, FAM_NAM, FAM_NAM));
 
     // Resetting and retrying. Will fail this time, not enough time for the second try
     SleepAndFailFirstTime.ct.set(0);
     try {
       table.setOperationTimeout(30 * 1000);
       table.put(new Put(FAM_NAM).addColumn(FAM_NAM, FAM_NAM, FAM_NAM));
       Assert.fail("We expect an exception here");
     } catch (RetriesExhaustedWithDetailsException e) {
       // The client has a CallTimeout class, but it's not shared.We're not very clean today,
       //  in the general case you can expect the call to stop, but the exception may vary.
       // In this test however, we're sure that it will be a socket timeout.
       LOG.info("We received an exception, as expected ", e);
     } catch (IOException e) {
       Assert.fail("Wrong exception:" + e.getMessage());
     } finally {
       table.close();
     }
   }
 
   @Test
   public void testDeleteOperationTimeout() throws Exception {
     HTableDescriptor hdt = TEST_UTIL.createTableDescriptor("HCM-testDeleteOperationTimeout");
     hdt.addCoprocessor(SleepAndFailFirstTime.class.getName());
     Table table = TEST_UTIL.createTable(hdt, new byte[][] { FAM_NAM },TEST_UTIL.getConfiguration());
     table.setRpcTimeout(Integer.MAX_VALUE);
     SleepAndFailFirstTime.ct.set(0);
     // Check that it works if the timeout is big enough
     table.setOperationTimeout(120 * 1000);
     table.delete(new Delete(FAM_NAM));
 
     // Resetting and retrying. Will fail this time, not enough time for the second try
     SleepAndFailFirstTime.ct.set(0);
     try {
       table.setOperationTimeout(30 * 1000);
       table.delete(new Delete(FAM_NAM));
       Assert.fail("We expect an exception here");
     } catch (IOException e) {
       // The client has a CallTimeout class, but it's not shared.We're not very clean today,
       //  in the general case you can expect the call to stop, but the exception may vary.
       // In this test however, we're sure that it will be a socket timeout.
       LOG.info("We received an exception, as expected ", e);
     } finally {
       table.close();
     }
   }
   @Test
   public void testDeleteRpcTimeout() throws Exception {
     HTableDescriptor hdt = TEST_UTIL.createTableDescriptor("HCM-testDeleteRpcTimeout");
     hdt.addCoprocessor(SleepCoprocessor.class.getName());
     Configuration c = new Configuration(TEST_UTIL.getConfiguration());
 
     try (Table t = TEST_UTIL.createTable(hdt, new byte[][] { FAM_NAM }, c)) {
       t.setRpcTimeout(SleepCoprocessor.SLEEP_TIME / 2);
       t.setOperationTimeout(SleepCoprocessor.SLEEP_TIME * 100);
       Delete d = new Delete(FAM_NAM);
       d.addColumn(FAM_NAM, FAM_NAM, 1);
       t.delete(d);
       fail("Write should not have succeeded");
     } catch (RetriesExhaustedException e) {
       // expected
     }
 
   }
 
   @Test
   public void testPutRpcTimeout() throws Exception {
     HTableDescriptor hdt = TEST_UTIL.createTableDescriptor("HCM-testPutRpcTimeout");
     hdt.addCoprocessor(SleepCoprocessor.class.getName());
     Configuration c = new Configuration(TEST_UTIL.getConfiguration());
 
     try (Table t = TEST_UTIL.createTable(hdt, new byte[][] { FAM_NAM }, c)) {
       t.setRpcTimeout(SleepCoprocessor.SLEEP_TIME / 2);
       t.setOperationTimeout(SleepCoprocessor.SLEEP_TIME * 100);
       Put p = new Put(FAM_NAM);
       p.addColumn(FAM_NAM, FAM_NAM, FAM_NAM);
       t.put(p);
       fail("Write should not have succeeded");
     } catch (IOException e) {
       // expected
     }
 
   }
 
   @Test(expected = RetriesExhaustedException.class)
   public void testRpcTimeout() throws Exception {
     HTableDescriptor hdt = TEST_UTIL.createTableDescriptor("HCM-testRpcTimeout");
     hdt.addCoprocessor(SleepCoprocessor.class.getName());
     Configuration c = new Configuration(TEST_UTIL.getConfiguration());
 
     try (Table t = TEST_UTIL.createTable(hdt, new byte[][] { FAM_NAM }, c)) {
       assert t instanceof HTable;
       HTable table = (HTable) t;
       table.setRpcTimeout(SleepCoprocessor.SLEEP_TIME / 2);
       table.setOperationTimeout(SleepCoprocessor.SLEEP_TIME * 100);
       table.get(new Get(FAM_NAM));
     }
   }
 
   @Test
   public void testDropTimeoutRequest() throws Exception {
     // Simulate the situation that the server is slow and client retries for several times because
     // of timeout. When a request can be handled after waiting in the queue, we will drop it if
     // it has been considered as timeout at client. If we don't drop it, the server will waste time
     // on handling timeout requests and finally all requests timeout and client throws exception.
     HTableDescriptor hdt = TEST_UTIL.createTableDescriptor("HCM-testDropTimeputRequest");
     hdt.addCoprocessor(SleepLongerAtFirstCoprocessor.class.getName());
     Configuration c = new Configuration(TEST_UTIL.getConfiguration());
     try (Table t = TEST_UTIL.createTable(hdt, new byte[][] { FAM_NAM }, c)) {
       t.setRpcTimeout(SleepLongerAtFirstCoprocessor.SLEEP_TIME * 2);
       t.get(new Get(FAM_NAM));
     }
   }
 
   /**
    * Test starting from 0 index when RpcRetryingCaller calculate the backoff time.
    */
   @Test
   public void testRpcRetryingCallerSleep() throws Exception {
     HTableDescriptor hdt = TEST_UTIL.createTableDescriptor("HCM-testRpcRetryingCallerSleep");
     hdt.addCoprocessorWithSpec("|" + SleepAndFailFirstTime.class.getName() + "||"
         + SleepAndFailFirstTime.SLEEP_TIME_CONF_KEY + "=2000");
     TEST_UTIL.createTable(hdt, new byte[][] { FAM_NAM }).close();
 
     Configuration c = new Configuration(TEST_UTIL.getConfiguration());
     SleepAndFailFirstTime.ct.set(0);
     c.setInt(HConstants.HBASE_CLIENT_PAUSE, 3000);
     c.setInt(HConstants.HBASE_RPC_TIMEOUT_KEY, 4000);
 
     Connection connection = ConnectionFactory.createConnection(c);
     Table t = connection.getTable(TableName.valueOf("HCM-testRpcRetryingCallerSleep"));
     if (t instanceof HTable) {
       HTable table = (HTable) t;
       table.setOperationTimeout(8000);
       // Check that it works. Because 2s + 3s * RETRY_BACKOFF[0] + 2s < 8s
       table.get(new Get(FAM_NAM));
 
       // Resetting and retrying.
       SleepAndFailFirstTime.ct.set(0);
       try {
         table.setOperationTimeout(6000);
         // Will fail this time. After sleep, there are not enough time for second retry
         // Beacuse 2s + 3s + 2s > 6s
         table.get(new Get(FAM_NAM));
         Assert.fail("We expect an exception here");
       } catch (SocketTimeoutException e) {
         LOG.info("We received an exception, as expected ", e);
       } catch (IOException e) {
         Assert.fail("Wrong exception:" + e.getMessage());
       } finally {
         table.close();
         connection.close();
       }
     }
   }
 
   @Test
   public void testCallableSleep() throws Exception {
     long pauseTime;
     long baseTime = 100;
     TableName tableName = TableName.valueOf("HCM-testCallableSleep");
     HTable table = TEST_UTIL.createTable(tableName, FAM_NAM);
     RegionServerCallable<Object> regionServerCallable = new RegionServerCallable<Object>(
         TEST_UTIL.getConnection(), tableName, ROW) {
       public Object call(int timeout) throws IOException {
         return null;
       }
     };
 
     regionServerCallable.prepare(false);
     for (int i = 0; i < HConstants.RETRY_BACKOFF.length; i++) {
       pauseTime = regionServerCallable.sleep(baseTime, i);
       assertTrue(pauseTime >= (baseTime * HConstants.RETRY_BACKOFF[i]));
       assertTrue(pauseTime <= (baseTime * HConstants.RETRY_BACKOFF[i] * 1.01f));
     }
 
     RegionAdminServiceCallable<Object> regionAdminServiceCallable =
         new RegionAdminServiceCallable<Object>(
         (ClusterConnection) TEST_UTIL.getConnection(), new RpcControllerFactory(
             TEST_UTIL.getConfiguration()), tableName, ROW) {
       public Object call(int timeout) throws IOException {
         return null;
       }
     };
 
     regionAdminServiceCallable.prepare(false);
     for (int i = 0; i < HConstants.RETRY_BACKOFF.length; i++) {
       pauseTime = regionAdminServiceCallable.sleep(baseTime, i);
       assertTrue(pauseTime >= (baseTime * HConstants.RETRY_BACKOFF[i]));
       assertTrue(pauseTime <= (baseTime * HConstants.RETRY_BACKOFF[i] * 1.01f));
     }
 
     MasterCallable masterCallable = new MasterCallable((HConnection) TEST_UTIL.getConnection()) {
       public Object call(int timeout) throws IOException {
         return null;
       }
     };
 
     for (int i = 0; i < HConstants.RETRY_BACKOFF.length; i++) {
       pauseTime = masterCallable.sleep(baseTime, i);
       assertTrue(pauseTime >= (baseTime * HConstants.RETRY_BACKOFF[i]));
       assertTrue(pauseTime <= (baseTime * HConstants.RETRY_BACKOFF[i] * 1.01f));
     }
   }
 
   private void testConnectionClose(boolean allowsInterrupt) throws Exception {
     TableName tableName = TableName.valueOf("HCM-testConnectionClose" + allowsInterrupt);
     TEST_UTIL.createTable(tableName, FAM_NAM).close();
 
     boolean previousBalance = TEST_UTIL.getHBaseAdmin().setBalancerRunning(false, true);
 
     Configuration c2 = new Configuration(TEST_UTIL.getConfiguration());
     // We want to work on a separate connection.
     c2.set(HConstants.HBASE_CLIENT_INSTANCE_ID, String.valueOf(-1));
     c2.setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 100); // retry a lot
     c2.setInt(HConstants.HBASE_CLIENT_PAUSE, 1); // don't wait between retries.
     c2.setInt(RpcClient.FAILED_SERVER_EXPIRY_KEY, 0); // Server do not really expire
     c2.setBoolean(RpcClient.SPECIFIC_WRITE_THREAD, allowsInterrupt);
 
     final HTable table = new HTable(c2, tableName);
 
     Put put = new Put(ROW);
     put.add(FAM_NAM, ROW, ROW);
     table.put(put);
 
     // 4 steps: ready=0; doGets=1; mustStop=2; stopped=3
     final AtomicInteger step = new AtomicInteger(0);
 
     final AtomicReference<Throwable> failed = new AtomicReference<Throwable>(null);
     Thread t = new Thread("testConnectionCloseThread") {
       @Override
       public void run() {
         int done = 0;
         try {
           step.set(1);
           while (step.get() == 1) {
             Get get = new Get(ROW);
             table.get(get);
             done++;
             if (done % 100 == 0)
               LOG.info("done=" + done);
           }
         } catch (Throwable t) {
           failed.set(t);
           LOG.error(t);
         }
         step.set(3);
       }
     };
     t.start();
     TEST_UTIL.waitFor(20000, new Waiter.Predicate<Exception>() {
       @Override
       public boolean evaluate() throws Exception {
         return step.get() == 1;
       }
     });
 
     ServerName sn = table.getRegionLocation(ROW).getServerName();
     ConnectionManager.HConnectionImplementation conn =
         (ConnectionManager.HConnectionImplementation) table.getConnection();
     RpcClient rpcClient = conn.getRpcClient();
 
     LOG.info("Going to cancel connections. connection=" + conn.toString() + ", sn=" + sn);
     for (int i = 0; i < 5000; i++) {
       rpcClient.cancelConnections(sn);
       Thread.sleep(5);
     }
 
     step.compareAndSet(1, 2);
     // The test may fail here if the thread doing the gets is stuck. The way to find
     //  out what's happening is to look for the thread named 'testConnectionCloseThread'
     TEST_UTIL.waitFor(40000, new Waiter.Predicate<Exception>() {
       @Override
       public boolean evaluate() throws Exception {
         return step.get() == 3;
       }
     });
     table.close();
     Assert.assertTrue("Unexpected exception is " + failed.get(), failed.get() == null);
     TEST_UTIL.getHBaseAdmin().setBalancerRunning(previousBalance, true);
   }
 
   /**
    * Test that connection can become idle without breaking everything.
    */
   @Test
   public void testConnectionIdle() throws Exception {
     TableName tableName = TableName.valueOf("HCM-testConnectionIdle");
     TEST_UTIL.createTable(tableName, FAM_NAM).close();
     int idleTime =  20000;
     boolean previousBalance = TEST_UTIL.getHBaseAdmin().setBalancerRunning(false, true);
 
     Configuration c2 = new Configuration(TEST_UTIL.getConfiguration());
     // We want to work on a separate connection.
     c2.set(HConstants.HBASE_CLIENT_INSTANCE_ID, String.valueOf(-1));
     c2.setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 1); // Don't retry: retry = test failed
     c2.setInt(RpcClient.IDLE_TIME, idleTime);
 
     final Table table = new HTable(c2, tableName);
 
     Put put = new Put(ROW);
     put.add(FAM_NAM, ROW, ROW);
     table.put(put);
 
     ManualEnvironmentEdge mee = new ManualEnvironmentEdge();
     mee.setValue(System.currentTimeMillis());
     EnvironmentEdgeManager.injectEdge(mee);
     LOG.info("first get");
     table.get(new Get(ROW));
 
     LOG.info("first get - changing the time & sleeping");
     mee.incValue(idleTime + 1000);
     Thread.sleep(1500); // we need to wait a little for the connection to be seen as idle.
                         // 1500 = sleep time in RpcClient#waitForWork + a margin
 
     LOG.info("second get - connection has been marked idle in the middle");
     // To check that the connection actually became idle would need to read some private
     //  fields of RpcClient.
     table.get(new Get(ROW));
     mee.incValue(idleTime + 1000);
 
     LOG.info("third get - connection is idle, but the reader doesn't know yet");
     // We're testing here a special case:
     //  time limit reached BUT connection not yet reclaimed AND a new call.
     //  in this situation, we don't close the connection, instead we use it immediately.
     // If we're very unlucky we can have a race condition in the test: the connection is already
     //  under closing when we do the get, so we have an exception, and we don't retry as the
     //  retry number is 1. The probability is very very low, and seems acceptable for now. It's
     //  a test issue only.
     table.get(new Get(ROW));
 
     LOG.info("we're done - time will change back");
 
     table.close();
     EnvironmentEdgeManager.reset();
     TEST_UTIL.getHBaseAdmin().setBalancerRunning(previousBalance, true);
   }
 
     /**
      * Test that the connection to the dead server is cut immediately when we receive the
      *  notification.
      * @throws Exception
      */
   @Test
   public void testConnectionCut() throws Exception {
 
     TableName tableName = TableName.valueOf("HCM-testConnectionCut");
 
     TEST_UTIL.createTable(tableName, FAM_NAM).close();
     boolean previousBalance = TEST_UTIL.getHBaseAdmin().setBalancerRunning(false, true);
 
     Configuration c2 = new Configuration(TEST_UTIL.getConfiguration());
     // We want to work on a separate connection.
     c2.set(HConstants.HBASE_CLIENT_INSTANCE_ID, String.valueOf(-1));
     c2.setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 1);
     c2.setInt(HConstants.HBASE_RPC_TIMEOUT_KEY, 30 * 1000);
 
     HTable table = new HTable(c2, tableName);
 
     Put p = new Put(FAM_NAM);
     p.add(FAM_NAM, FAM_NAM, FAM_NAM);
     table.put(p);
 
     final HConnectionImplementation hci =  (HConnectionImplementation)table.getConnection();
     final HRegionLocation loc = table.getRegionLocation(FAM_NAM);
 
     Get get = new Get(FAM_NAM);
     Assert.assertNotNull(table.get(get));
 
     get = new Get(FAM_NAM);
     get.setFilter(new BlockingFilter());
 
     // This thread will mark the server as dead while we're waiting during a get.
     Thread t = new Thread() {
       @Override
       public void run() {
         synchronized (syncBlockingFilter) {
           try {
             syncBlockingFilter.wait();
           } catch (InterruptedException e) {
             throw new RuntimeException(e);
           }
         }
         hci.clusterStatusListener.deadServerHandler.newDead(loc.getServerName());
       }
     };
 
     t.start();
     try {
       table.get(get);
       Assert.fail();
     } catch (IOException expected) {
       LOG.debug("Received: " + expected);
       Assert.assertFalse(expected instanceof SocketTimeoutException);
       Assert.assertFalse(syncBlockingFilter.get());
     } finally {
       syncBlockingFilter.set(true);
       t.join();
       HConnectionManager.getConnection(c2).close();
       TEST_UTIL.getHBaseAdmin().setBalancerRunning(previousBalance, true);
     }
 
     table.close();
   }
 
   protected static final AtomicBoolean syncBlockingFilter = new AtomicBoolean(false);
 
   public static class BlockingFilter extends FilterBase {
     @Override
     public boolean filterRowKey(byte[] buffer, int offset, int length) throws IOException {
       int i = 0;
       while (i++ < 1000 && !syncBlockingFilter.get()) {
         synchronized (syncBlockingFilter) {
           syncBlockingFilter.notifyAll();
         }
         Threads.sleep(100);
       }
       syncBlockingFilter.set(true);
       return false;
     }
     @Override
     public ReturnCode filterKeyValue(Cell ignored) throws IOException {
       return ReturnCode.INCLUDE;
     }
 
     public static Filter parseFrom(final byte [] pbBytes) throws DeserializationException{
       return new BlockingFilter();
     }
   }
 
   @Test (timeout=120000)
   public void abortingHConnectionRemovesItselfFromHCM() throws Exception {
     // Save off current HConnections
     Map<HConnectionKey, HConnectionImplementation> oldHBaseInstances =
         new HashMap<HConnectionKey, HConnectionImplementation>();
     oldHBaseInstances.putAll(ConnectionManager.CONNECTION_INSTANCES);
 
     ConnectionManager.CONNECTION_INSTANCES.clear();
 
     try {
       HConnection connection = HConnectionManager.getConnection(TEST_UTIL.getConfiguration());
       connection.abort("test abortingHConnectionRemovesItselfFromHCM", new Exception(
           "test abortingHConnectionRemovesItselfFromHCM"));
       Assert.assertNotSame(connection,
         HConnectionManager.getConnection(TEST_UTIL.getConfiguration()));
     } finally {
       // Put original HConnections back
       ConnectionManager.CONNECTION_INSTANCES.clear();
       ConnectionManager.CONNECTION_INSTANCES.putAll(oldHBaseInstances);
     }
   }
 
   /**
    * Test that when we delete a location using the first row of a region
    * that we really delete it.
    * @throws Exception
    */
   @Test
   public void testRegionCaching() throws Exception{
     TEST_UTIL.createMultiRegionTable(TABLE_NAME, FAM_NAM).close();
     Configuration conf =  new Configuration(TEST_UTIL.getConfiguration());
     conf.setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 1);
     HTable table = new HTable(conf, TABLE_NAME);
 
     TEST_UTIL.waitUntilAllRegionsAssigned(table.getName());
     Put put = new Put(ROW);
     put.add(FAM_NAM, ROW, ROW);
     table.put(put);
     ConnectionManager.HConnectionImplementation conn =
       (ConnectionManager.HConnectionImplementation)table.getConnection();
 
     assertNotNull(conn.getCachedLocation(TABLE_NAME, ROW));
 
     final int nextPort = conn.getCachedLocation(TABLE_NAME, ROW).getRegionLocation().getPort() + 1;
     HRegionLocation loc = conn.getCachedLocation(TABLE_NAME, ROW).getRegionLocation();
     conn.updateCachedLocation(loc.getRegionInfo(), loc.getServerName(),
         ServerName.valueOf("127.0.0.1", nextPort,
         HConstants.LATEST_TIMESTAMP), HConstants.LATEST_TIMESTAMP);
     Assert.assertEquals(conn.getCachedLocation(TABLE_NAME, ROW)
       .getRegionLocation().getPort(), nextPort);
 
     conn.clearRegionCache(TABLE_NAME, ROW.clone());
     RegionLocations rl = conn.getCachedLocation(TABLE_NAME, ROW);
     assertNull("What is this location?? " + rl, rl);
 
     // We're now going to move the region and check that it works for the client
     // First a new put to add the location in the cache
     conn.clearRegionCache(TABLE_NAME);
     Assert.assertEquals(0, conn.getNumberOfCachedRegionLocations(TABLE_NAME));
     Put put2 = new Put(ROW);
     put2.add(FAM_NAM, ROW, ROW);
     table.put(put2);
     assertNotNull(conn.getCachedLocation(TABLE_NAME, ROW));
     assertNotNull(conn.getCachedLocation(TableName.valueOf(TABLE_NAME.getName()), ROW.clone()));
 
     TEST_UTIL.getHBaseAdmin().setBalancerRunning(false, false);
     HMaster master = TEST_UTIL.getMiniHBaseCluster().getMaster();
 
     // We can wait for all regions to be online, that makes log reading easier when debugging
     TEST_UTIL.waitUntilNoRegionsInTransition();
 
     // Now moving the region to the second server
     HRegionLocation toMove = conn.getCachedLocation(TABLE_NAME, ROW).getRegionLocation();
     byte[] regionName = toMove.getRegionInfo().getRegionName();
     byte[] encodedRegionNameBytes = toMove.getRegionInfo().getEncodedNameAsBytes();
 
     // Choose the other server.
     int curServerId = TEST_UTIL.getHBaseCluster().getServerWith(regionName);
     int destServerId = (curServerId == 0 ? 1 : 0);
 
     HRegionServer curServer = TEST_UTIL.getHBaseCluster().getRegionServer(curServerId);
     HRegionServer destServer = TEST_UTIL.getHBaseCluster().getRegionServer(destServerId);
 
     ServerName destServerName = destServer.getServerName();
 
     // Check that we are in the expected state
     Assert.assertTrue(curServer != destServer);
     Assert.assertFalse(curServer.getServerName().equals(destServer.getServerName()));
     Assert.assertFalse( toMove.getPort() == destServerName.getPort());
     Assert.assertNotNull(curServer.getOnlineRegion(regionName));
     Assert.assertNull(destServer.getOnlineRegion(regionName));
     Assert.assertFalse(TEST_UTIL.getMiniHBaseCluster().getMaster().
         getAssignmentManager().getRegionStates().isRegionsInTransition());
 
     // Moving. It's possible that we don't have all the regions online at this point, so
     //  the test must depends only on the region we're looking at.
     LOG.info("Move starting region="+toMove.getRegionInfo().getRegionNameAsString());
     TEST_UTIL.getHBaseAdmin().move(
       toMove.getRegionInfo().getEncodedNameAsBytes(),
       destServerName.getServerName().getBytes()
     );
 
     while (destServer.getOnlineRegion(regionName) == null ||
         destServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameBytes) ||
         curServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameBytes) ||
         master.getAssignmentManager().getRegionStates().isRegionsInTransition()) {
       // wait for the move to be finished
       Thread.sleep(1);
     }
 
     LOG.info("Move finished for region="+toMove.getRegionInfo().getRegionNameAsString());
 
     // Check our new state.
     Assert.assertNull(curServer.getOnlineRegion(regionName));
     Assert.assertNotNull(destServer.getOnlineRegion(regionName));
     Assert.assertFalse(destServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameBytes));
     Assert.assertFalse(curServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameBytes));
 
 
     // Cache was NOT updated and points to the wrong server
     Assert.assertFalse(
         conn.getCachedLocation(TABLE_NAME, ROW).getRegionLocation()
           .getPort() == destServerName.getPort());
 
     // This part relies on a number of tries equals to 1.
     // We do a put and expect the cache to be updated, even if we don't retry
     LOG.info("Put starting");
     Put put3 = new Put(ROW);
     put3.add(FAM_NAM, ROW, ROW);
     try {
       table.put(put3);
       Assert.fail("Unreachable point");
     } catch (RetriesExhaustedWithDetailsException e){
       LOG.info("Put done, exception caught: " + e.getClass());
       Assert.assertEquals(1, e.getNumExceptions());
       Assert.assertEquals(1, e.getCauses().size());
       Assert.assertArrayEquals(e.getRow(0).getRow(), ROW);
 
       // Check that we unserialized the exception as expected
       Throwable cause = ClientExceptionsUtil.findException(e.getCause(0));
       Assert.assertNotNull(cause);
       Assert.assertTrue(cause instanceof RegionMovedException);
     }
     Assert.assertNotNull("Cached connection is null", conn.getCachedLocation(TABLE_NAME, ROW));
     Assert.assertEquals(
         "Previous server was " + curServer.getServerName().getHostAndPort(),
         destServerName.getPort(),
         conn.getCachedLocation(TABLE_NAME, ROW).getRegionLocation().getPort());
 
     Assert.assertFalse(destServer.getRegionsInTransitionInRS()
       .containsKey(encodedRegionNameBytes));
     Assert.assertFalse(curServer.getRegionsInTransitionInRS()
       .containsKey(encodedRegionNameBytes));
 
     // We move it back to do another test with a scan
     LOG.info("Move starting region=" + toMove.getRegionInfo().getRegionNameAsString());
     TEST_UTIL.getHBaseAdmin().move(
       toMove.getRegionInfo().getEncodedNameAsBytes(),
       curServer.getServerName().getServerName().getBytes()
     );
 
     while (curServer.getOnlineRegion(regionName) == null ||
         destServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameBytes) ||
         curServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameBytes) ||
         master.getAssignmentManager().getRegionStates().isRegionsInTransition()) {
       // wait for the move to be finished
       Thread.sleep(1);
     }
 
     // Check our new state.
     Assert.assertNotNull(curServer.getOnlineRegion(regionName));
     Assert.assertNull(destServer.getOnlineRegion(regionName));
     LOG.info("Move finished for region=" + toMove.getRegionInfo().getRegionNameAsString());
 
     // Cache was NOT updated and points to the wrong server
     Assert.assertFalse(conn.getCachedLocation(TABLE_NAME, ROW).getRegionLocation().getPort() ==
       curServer.getServerName().getPort());
 
     Scan sc = new Scan();
     sc.setStopRow(ROW);
     sc.setStartRow(ROW);
 
     // The scanner takes the max retries from the connection configuration, not the table as
     // the put.
     TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 1);
 
     try {
       ResultScanner rs = table.getScanner(sc);
       while (rs.next() != null) {
       }
       Assert.fail("Unreachable point");
     } catch (RetriesExhaustedException e) {
       LOG.info("Scan done, expected exception caught: " + e.getClass());
     }
 
     // Cache is updated with the right value.
     Assert.assertNotNull(conn.getCachedLocation(TABLE_NAME, ROW));
     Assert.assertEquals(
       "Previous server was "+destServer.getServerName().getHostAndPort(),
       curServer.getServerName().getPort(),
       conn.getCachedLocation(TABLE_NAME, ROW).getRegionLocation().getPort());
 
     TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, RPC_RETRY);
     table.close();
   }
 
   /**
    * Test that Connection or Pool are not closed when managed externally
    * @throws Exception
    */
   @Test
   public void testConnectionManagement() throws Exception{
     Table table0 = TEST_UTIL.createTable(TABLE_NAME1, FAM_NAM);
     Connection conn = ConnectionFactory.createConnection(TEST_UTIL.getConfiguration());
     HTable table = (HTable) conn.getTable(TABLE_NAME1);
     table.close();
     assertFalse(conn.isClosed());
     assertFalse(table.getPool().isShutdown());
     table = (HTable) conn.getTable(TABLE_NAME1);
     table.close();
     assertFalse(table.getPool().isShutdown());
     conn.close();
     assertTrue(table.getPool().isShutdown());
     table0.close();
   }
 
   /**
    * Test that stale cache updates don't override newer cached values.
    */
   @Test
   public void testCacheSeqNums() throws Exception{
     HTable table = TEST_UTIL.createMultiRegionTable(TABLE_NAME2, FAM_NAM);
     Put put = new Put(ROW);
     put.add(FAM_NAM, ROW, ROW);
     table.put(put);
     ConnectionManager.HConnectionImplementation conn =
       (ConnectionManager.HConnectionImplementation)table.getConnection();
 
     HRegionLocation location = conn.getCachedLocation(TABLE_NAME2, ROW).getRegionLocation();
     assertNotNull(location);
 
     ServerName anySource = ServerName.valueOf(location.getHostname(), location.getPort() - 1, 0L);
 
     // Same server as already in cache reporting - overwrites any value despite seqNum.
     int nextPort = location.getPort() + 1;
     conn.updateCachedLocation(location.getRegionInfo(), location.getServerName(),
         ServerName.valueOf("127.0.0.1", nextPort, 0), location.getSeqNum() - 1);
     location = conn.getCachedLocation(TABLE_NAME2, ROW).getRegionLocation();
     Assert.assertEquals(nextPort, location.getPort());
 
     // No source specified - same.
     nextPort = location.getPort() + 1;
     conn.updateCachedLocation(location.getRegionInfo(), location.getServerName(),
         ServerName.valueOf("127.0.0.1", nextPort, 0), location.getSeqNum() - 1);
     location = conn.getCachedLocation(TABLE_NAME2, ROW).getRegionLocation();
     Assert.assertEquals(nextPort, location.getPort());
 
     // Higher seqNum - overwrites lower seqNum.
     nextPort = location.getPort() + 1;
     conn.updateCachedLocation(location.getRegionInfo(), anySource,
         ServerName.valueOf("127.0.0.1", nextPort, 0), location.getSeqNum() + 1);
     location = conn.getCachedLocation(TABLE_NAME2, ROW).getRegionLocation();
     Assert.assertEquals(nextPort, location.getPort());
 
     // Lower seqNum - does not overwrite higher seqNum.
     nextPort = location.getPort() + 1;
     conn.updateCachedLocation(location.getRegionInfo(), anySource,
         ServerName.valueOf("127.0.0.1", nextPort, 0), location.getSeqNum() - 1);
     location = conn.getCachedLocation(TABLE_NAME2, ROW).getRegionLocation();
     Assert.assertEquals(nextPort - 1, location.getPort());
     table.close();
   }
 
   /**
    * Make sure that {@link Configuration} instances that are essentially the
    * same map to the same {@link HConnection} instance.
    */
   @Test
   public void testConnectionSameness() throws Exception {
     Connection previousConnection = null;
     for (int i = 0; i < 2; i++) {
       // set random key to differentiate the connection from previous ones
       Configuration configuration = TEST_UTIL.getConfiguration();
       configuration.set("some_key", String.valueOf(_randy.nextInt()));
       LOG.info("The hash code of the current configuration is: "
           + configuration.hashCode());
       Connection currentConnection = HConnectionManager
           .getConnection(configuration);
       if (previousConnection != null) {
         assertTrue(
             "Did not get the same connection even though its key didn't change",
             previousConnection == currentConnection);
       }
       previousConnection = currentConnection;
       // change the configuration, so that it is no longer reachable from the
       // client's perspective. However, since its part of the LRU doubly linked
       // list, it will eventually get thrown out, at which time it should also
       // close the corresponding {@link HConnection}.
       configuration.set("other_key", String.valueOf(_randy.nextInt()));
     }
   }
 
   /**
    * Makes sure that there is no leaking of
    * {@link ConnectionManager.HConnectionImplementation} in the {@link HConnectionManager}
    * class.
    * @deprecated Tests deprecated functionality.  Remove in 1.0.
    */
   @Deprecated
   @Test
   public void testConnectionUniqueness() throws Exception {
     int zkmaxconnections = TEST_UTIL.getConfiguration().
       getInt(HConstants.ZOOKEEPER_MAX_CLIENT_CNXNS,
           HConstants.DEFAULT_ZOOKEPER_MAX_CLIENT_CNXNS);
     // Test up to a max that is < the maximum number of zk connections.  If we
     // go above zk connections, we just fall into cycle where we are failing
     // to set up a session and test runs for a long time.
     int maxConnections = Math.min(zkmaxconnections - 1, 20);
     List<HConnection> connections = new ArrayList<HConnection>(maxConnections);
     Connection previousConnection = null;
     try {
       for (int i = 0; i < maxConnections; i++) {
         // set random key to differentiate the connection from previous ones
         Configuration configuration = new Configuration(TEST_UTIL.getConfiguration());
         configuration.set("some_key", String.valueOf(_randy.nextInt()));
         configuration.set(HConstants.HBASE_CLIENT_INSTANCE_ID,
             String.valueOf(_randy.nextInt()));
         LOG.info("The hash code of the current configuration is: "
             + configuration.hashCode());
         HConnection currentConnection =
           HConnectionManager.getConnection(configuration);
         if (previousConnection != null) {
           assertTrue("Got the same connection even though its key changed!",
               previousConnection != currentConnection);
         }
         // change the configuration, so that it is no longer reachable from the
         // client's perspective. However, since its part of the LRU doubly linked
         // list, it will eventually get thrown out, at which time it should also
         // close the corresponding {@link HConnection}.
         configuration.set("other_key", String.valueOf(_randy.nextInt()));
 
         previousConnection = currentConnection;
         LOG.info("The current HConnectionManager#HBASE_INSTANCES cache size is: "
             + getHConnectionManagerCacheSize());
         Thread.sleep(50);
         connections.add(currentConnection);
       }
     } finally {
       for (Connection c: connections) {
         // Clean up connections made so we don't interfere w/ subsequent tests.
         HConnectionManager.deleteConnection(c.getConfiguration());
       }
     }
   }
 
   @Test
   public void testClosing() throws Exception {
     Configuration configuration =
       new Configuration(TEST_UTIL.getConfiguration());
     configuration.set(HConstants.HBASE_CLIENT_INSTANCE_ID,
         String.valueOf(_randy.nextInt()));
 
     Connection c1 = ConnectionFactory.createConnection(configuration);
     // We create two connections with the same key.
     Connection c2 = ConnectionFactory.createConnection(configuration);
 
     Connection c3 = HConnectionManager.getConnection(configuration);
     Connection c4 = HConnectionManager.getConnection(configuration);
     assertTrue(c3 == c4);
 
     c1.close();
     assertTrue(c1.isClosed());
     assertFalse(c2.isClosed());
     assertFalse(c3.isClosed());
 
     c3.close();
     // still a reference left
     assertFalse(c3.isClosed());
     c3.close();
     assertTrue(c3.isClosed());
     // c3 was removed from the cache
     Connection c5 = HConnectionManager.getConnection(configuration);
     assertTrue(c5 != c3);
 
     assertFalse(c2.isClosed());
     c2.close();
     assertTrue(c2.isClosed());
     c5.close();
     assertTrue(c5.isClosed());
   }
 
   /**
    * Trivial test to verify that nobody messes with
    * {@link HConnectionManager#createConnection(Configuration)}
    */
   @Test
   public void testCreateConnection() throws Exception {
     Configuration configuration = TEST_UTIL.getConfiguration();
     Connection c1 = ConnectionFactory.createConnection(configuration);
     Connection c2 = ConnectionFactory.createConnection(configuration);
     // created from the same configuration, yet they are different
     assertTrue(c1 != c2);
     assertTrue(c1.getConfiguration() == c2.getConfiguration());
     // make sure these were not cached
     Connection c3 = HConnectionManager.getConnection(configuration);
     assertTrue(c1 != c3);
     assertTrue(c2 != c3);
   }
 
 
   /**
    * This test checks that one can connect to the cluster with only the
    *  ZooKeeper quorum set. Other stuff like master address will be read
    *  from ZK by the client.
    */
   @Test
   public void testConnection() throws Exception{
     // We create an empty config and add the ZK address.
     Configuration c = new Configuration();
     c.set(HConstants.ZOOKEEPER_QUORUM,
       TEST_UTIL.getConfiguration().get(HConstants.ZOOKEEPER_QUORUM));
     c.set(HConstants.ZOOKEEPER_CLIENT_PORT ,
       TEST_UTIL.getConfiguration().get(HConstants.ZOOKEEPER_CLIENT_PORT));
 
     // This should be enough to connect
     HConnection conn = HConnectionManager.getConnection(c);
     assertTrue( conn.isMasterRunning() );
     conn.close();
   }
 
   private int setNumTries(HConnectionImplementation hci, int newVal) throws Exception {
     Field numTries = hci.getClass().getDeclaredField("numTries");
     numTries.setAccessible(true);
     Field modifiersField = Field.class.getDeclaredField("modifiers");
     modifiersField.setAccessible(true);
     modifiersField.setInt(numTries, numTries.getModifiers() & ~Modifier.FINAL);
     final int prevNumRetriesVal = (Integer)numTries.get(hci);
     numTries.set(hci, newVal);
 
     return prevNumRetriesVal;
   }
 
   @Test
   public void testMulti() throws Exception {
     HTable table = TEST_UTIL.createMultiRegionTable(TABLE_NAME3, FAM_NAM);
     try {
        ConnectionManager.HConnectionImplementation conn =
            ( ConnectionManager.HConnectionImplementation)table.getConnection();
 
        // We're now going to move the region and check that it works for the client
        // First a new put to add the location in the cache
        conn.clearRegionCache(TABLE_NAME3);
        Assert.assertEquals(0, conn.getNumberOfCachedRegionLocations(TABLE_NAME3));
 
        TEST_UTIL.getHBaseAdmin().setBalancerRunning(false, false);
        HMaster master = TEST_UTIL.getMiniHBaseCluster().getMaster();
 
        // We can wait for all regions to be online, that makes log reading easier when debugging
        TEST_UTIL.waitUntilNoRegionsInTransition();
 
        Put put = new Put(ROW_X);
        put.add(FAM_NAM, ROW_X, ROW_X);
        table.put(put);
 
        // Now moving the region to the second server
        HRegionLocation toMove = conn.getCachedLocation(TABLE_NAME3, ROW_X).getRegionLocation();
        byte[] regionName = toMove.getRegionInfo().getRegionName();
        byte[] encodedRegionNameBytes = toMove.getRegionInfo().getEncodedNameAsBytes();
 
        // Choose the other server.
        int curServerId = TEST_UTIL.getHBaseCluster().getServerWith(regionName);
        int destServerId = (curServerId == 0 ? 1 : 0);
 
        HRegionServer curServer = TEST_UTIL.getHBaseCluster().getRegionServer(curServerId);
        HRegionServer destServer = TEST_UTIL.getHBaseCluster().getRegionServer(destServerId);
 
        ServerName destServerName = destServer.getServerName();
 
        //find another row in the cur server that is less than ROW_X
        List<Region> regions = curServer.getOnlineRegions(TABLE_NAME3);
        byte[] otherRow = null;
        for (Region region : regions) {
          if (!region.getRegionInfo().getEncodedName().equals(toMove.getRegionInfo().getEncodedName())
              && Bytes.BYTES_COMPARATOR.compare(region.getRegionInfo().getStartKey(), ROW_X) < 0) {
            otherRow = region.getRegionInfo().getStartKey();
            break;
          }
        }
        assertNotNull(otherRow);
        // If empty row, set it to first row.-f
        if (otherRow.length <= 0) otherRow = Bytes.toBytes("aaa");
        Put put2 = new Put(otherRow);
        put2.add(FAM_NAM, otherRow, otherRow);
        table.put(put2); //cache put2's location
 
        // Check that we are in the expected state
        Assert.assertTrue(curServer != destServer);
        Assert.assertNotEquals(curServer.getServerName(), destServer.getServerName());
        Assert.assertNotEquals(toMove.getPort(), destServerName.getPort());
        Assert.assertNotNull(curServer.getOnlineRegion(regionName));
        Assert.assertNull(destServer.getOnlineRegion(regionName));
        Assert.assertFalse(TEST_UTIL.getMiniHBaseCluster().getMaster().
            getAssignmentManager().getRegionStates().isRegionsInTransition());
 
        // Moving. It's possible that we don't have all the regions online at this point, so
        //  the test must depends only on the region we're looking at.
        LOG.info("Move starting region="+toMove.getRegionInfo().getRegionNameAsString());
        TEST_UTIL.getHBaseAdmin().move(
            toMove.getRegionInfo().getEncodedNameAsBytes(),
            destServerName.getServerName().getBytes()
            );
 
        while (destServer.getOnlineRegion(regionName) == null ||
            destServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameBytes) ||
            curServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameBytes) ||
            master.getAssignmentManager().getRegionStates().isRegionsInTransition()) {
          // wait for the move to be finished
          Thread.sleep(1);
         }
 
        LOG.info("Move finished for region="+toMove.getRegionInfo().getRegionNameAsString());
 
        // Check our new state.
        Assert.assertNull(curServer.getOnlineRegion(regionName));
        Assert.assertNotNull(destServer.getOnlineRegion(regionName));
        Assert.assertFalse(destServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameBytes));
        Assert.assertFalse(curServer.getRegionsInTransitionInRS().containsKey(encodedRegionNameBytes));
 
 
        // Cache was NOT updated and points to the wrong server
        Assert.assertFalse(
            conn.getCachedLocation(TABLE_NAME3, ROW_X).getRegionLocation()
             .getPort() == destServerName.getPort());
 
        // Hijack the number of retry to fail after 2 tries
        final int prevNumRetriesVal = setNumTries(conn, 2);
 
        Put put3 = new Put(ROW_X);
        put3.add(FAM_NAM, ROW_X, ROW_X);
        Put put4 = new Put(otherRow);
        put4.add(FAM_NAM, otherRow, otherRow);
 
        // do multi
        table.batch(Lists.newArrayList(put4, put3)); // first should be a valid row,
        // second we get RegionMovedException.
 
        setNumTries(conn, prevNumRetriesVal);
      } finally {
        table.close();
      }
   }
 
   @Test
   public void testErrorBackoffTimeCalculation() throws Exception {
     // TODO: This test would seem to presume hardcoded RETRY_BACKOFF which it should not.
     final long ANY_PAUSE = 100;
     ServerName location = ServerName.valueOf("127.0.0.1", 1, 0);
     ServerName diffLocation = ServerName.valueOf("127.0.0.1", 2, 0);
 
     ManualEnvironmentEdge timeMachine = new ManualEnvironmentEdge();
     EnvironmentEdgeManager.injectEdge(timeMachine);
     try {
       long timeBase = timeMachine.currentTime();
       long largeAmountOfTime = ANY_PAUSE * 1000;
       ConnectionManager.ServerErrorTracker tracker =
           new ConnectionManager.ServerErrorTracker(largeAmountOfTime, 100);
 
       // The default backoff is 0.
       assertEquals(0, tracker.calculateBackoffTime(location, ANY_PAUSE));
 
       // Check some backoff values from HConstants sequence.
       tracker.reportServerError(location);
       assertEqualsWithJitter(ANY_PAUSE * HConstants.RETRY_BACKOFF[0],
         tracker.calculateBackoffTime(location, ANY_PAUSE));
       tracker.reportServerError(location);
       tracker.reportServerError(location);
       tracker.reportServerError(location);
       assertEqualsWithJitter(ANY_PAUSE * HConstants.RETRY_BACKOFF[3],
         tracker.calculateBackoffTime(location, ANY_PAUSE));
 
       // All of this shouldn't affect backoff for different location.
       assertEquals(0, tracker.calculateBackoffTime(diffLocation, ANY_PAUSE));
       tracker.reportServerError(diffLocation);
       assertEqualsWithJitter(ANY_PAUSE * HConstants.RETRY_BACKOFF[0],
         tracker.calculateBackoffTime(diffLocation, ANY_PAUSE));
 
       // Check with different base.
       assertEqualsWithJitter(ANY_PAUSE * 2 * HConstants.RETRY_BACKOFF[3],
           tracker.calculateBackoffTime(location, ANY_PAUSE * 2));
     } finally {
       EnvironmentEdgeManager.reset();
     }
   }
 
   private static void assertEqualsWithJitter(long expected, long actual) {
     assertEqualsWithJitter(expected, actual, expected);
   }
 
   private static void assertEqualsWithJitter(long expected, long actual, long jitterBase) {
     assertTrue("Value not within jitter: " + expected + " vs " + actual,
         Math.abs(actual - expected) <= (0.01f * jitterBase));
   }
 
   /**
    * Tests that a destroyed connection does not have a live zookeeper.
    * Below is timing based.  We put up a connection to a table and then close the connection while
    * having a background thread running that is forcing close of the connection to try and
    * provoke a close catastrophe; we are hoping for a car crash so we can see if we are leaking
    * zk connections.
    * @throws Exception
    */
   @Ignore ("Flakey test: See HBASE-8996")@Test
   public void testDeleteForZKConnLeak() throws Exception {
     TEST_UTIL.createTable(TABLE_NAME4, FAM_NAM);
     final Configuration config = HBaseConfiguration.create(TEST_UTIL.getConfiguration());
     config.setInt("zookeeper.recovery.retry", 1);
     config.setInt("zookeeper.recovery.retry.intervalmill", 1000);
     config.setInt("hbase.rpc.timeout", 2000);
     config.setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 1);
 
     ThreadPoolExecutor pool = new ThreadPoolExecutor(1, 10,
       5, TimeUnit.SECONDS,
       new SynchronousQueue<Runnable>(),
       Threads.newDaemonThreadFactory("test-hcm-delete"));
 
     pool.submit(new Runnable() {
       @Override
       public void run() {
         while (!Thread.interrupted()) {
           try {
             HConnection conn = HConnectionManager.getConnection(config);
             LOG.info("Connection " + conn);
             HConnectionManager.deleteStaleConnection(conn);
             LOG.info("Connection closed " + conn);
             // TODO: This sleep time should be less than the time that it takes to open and close
             // a table.  Ideally we would do a few runs first to measure.  For now this is
             // timing based; hopefully we hit the bad condition.
             Threads.sleep(10);
           } catch (Exception e) {
           }
         }
       }
     });
 
     // Use connection multiple times.
     for (int i = 0; i < 30; i++) {
       Connection c1 = null;
       try {
         c1 = ConnectionManager.getConnectionInternal(config);
         LOG.info("HTable connection " + i + " " + c1);
         Table table = new HTable(config, TABLE_NAME4, pool);
         table.close();
         LOG.info("HTable connection " + i + " closed " + c1);
       } catch (Exception e) {
         LOG.info("We actually want this to happen!!!!  So we can see if we are leaking zk", e);
       } finally {
         if (c1 != null) {
           if (c1.isClosed()) {
             // cannot use getZooKeeper as method instantiates watcher if null
             Field zkwField = c1.getClass().getDeclaredField("keepAliveZookeeper");
             zkwField.setAccessible(true);
             Object watcher = zkwField.get(c1);
 
             if (watcher != null) {
               if (((ZooKeeperWatcher)watcher).getRecoverableZooKeeper().getState().isAlive()) {
                 // non-synchronized access to watcher; sleep and check again in case zk connection
                 // hasn't been cleaned up yet.
                 Thread.sleep(1000);
                 if (((ZooKeeperWatcher) watcher).getRecoverableZooKeeper().getState().isAlive()) {
                   pool.shutdownNow();
                   fail("Live zookeeper in closed connection");
                 }
               }
             }
           }
           c1.close();
         }
       }
     }
     pool.shutdownNow();
   }
 
   @Test
   public void testConnectionRideOverClusterRestart() throws IOException, InterruptedException {
     Configuration config = new Configuration(TEST_UTIL.getConfiguration());
 
     TableName tableName = TableName.valueOf("testConnectionRideOverClusterRestart");
     TEST_UTIL.createTable(tableName.getName(), new byte[][] {FAM_NAM}, config).close();
 
     Connection connection = ConnectionFactory.createConnection(config);
     Table table = connection.getTable(tableName);
 
     // this will cache the meta location and table's region location
     table.get(new Get(Bytes.toBytes("foo")));
 
     // restart HBase
     TEST_UTIL.shutdownMiniHBaseCluster();
     TEST_UTIL.restartHBaseCluster(2);
     // this should be able to discover new locations for meta and table's region
     table.get(new Get(Bytes.toBytes("foo")));
     TEST_UTIL.deleteTable(tableName);
     table.close();
     connection.close();
   }
 }