/**
    *
    * 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;
  
  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 java.io.IOException;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.client.Admin;
  import org.apache.hadoop.hbase.client.Get;
  import org.apache.hadoop.hbase.client.HConnection;
  import org.apache.hadoop.hbase.client.HConnectionManager;
  import org.apache.hadoop.hbase.client.HTable;
  import org.apache.hadoop.hbase.client.Put;
  import org.apache.hadoop.hbase.client.Result;
  import org.apache.hadoop.hbase.client.ResultScanner;
  import org.apache.hadoop.hbase.client.Scan;
  import org.apache.hadoop.hbase.client.Table;
  import org.apache.hadoop.hbase.coordination.ZkSplitLogWorkerCoordination;
  import org.apache.hadoop.hbase.master.HMaster;
  import org.apache.hadoop.hbase.master.LoadBalancer;
  import org.apache.hadoop.hbase.master.balancer.SimpleLoadBalancer;
  import org.apache.hadoop.hbase.testclassification.LargeTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.FSUtils;
  import org.apache.hadoop.hbase.util.Threads;
  import org.apache.hadoop.hbase.zookeeper.EmptyWatcher;
  import org.apache.hadoop.hbase.zookeeper.ZKAssign;
  import org.apache.hadoop.hbase.zookeeper.ZKConfig;
  import org.apache.hadoop.hbase.zookeeper.ZKUtil;
  import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
  import org.apache.zookeeper.CreateMode;
  import org.apache.zookeeper.KeeperException;
  import org.apache.zookeeper.ZooDefs;
  import org.apache.zookeeper.ZooKeeper;
  import org.apache.zookeeper.ZooKeeper.States;
  import org.apache.zookeeper.data.ACL;
  import org.apache.zookeeper.data.Stat;
  import org.junit.After;
  import org.junit.AfterClass;
  import org.junit.Assert;
  import org.junit.Before;
  import org.junit.BeforeClass;
  import org.junit.Ignore;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  
  
  @Category(LargeTests.class)
  public class TestZooKeeper {
    private static final Log LOG = LogFactory.getLog(TestZooKeeper.class);
  
    private final static HBaseTestingUtility
        TEST_UTIL = new HBaseTestingUtility();
  
    /**
     * @throws java.lang.Exception
     */
    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
      // Test we can first start the ZK cluster by itself
      Configuration conf = TEST_UTIL.getConfiguration();
      TEST_UTIL.startMiniDFSCluster(2);
      TEST_UTIL.startMiniZKCluster();
      conf.setBoolean("dfs.support.append", true);
      conf.setInt(HConstants.ZK_SESSION_TIMEOUT, 1000);
      conf.setClass(HConstants.HBASE_MASTER_LOADBALANCER_CLASS, MockLoadBalancer.class,
          LoadBalancer.class);
    }
  
   /**
    * @throws java.lang.Exception
    */
   @AfterClass
   public static void tearDownAfterClass() throws Exception {
     TEST_UTIL.shutdownMiniCluster();
   }
 
   /**
    * @throws java.lang.Exception
    */
   @Before
   public void setUp() throws Exception {
     TEST_UTIL.startMiniHBaseCluster(2, 2);
   }
 
   @After
   public void after() throws Exception {
     try {
       // Some regionserver could fail to delete its znode.
       // So shutdown could hang. Let's kill them all instead.
       TEST_UTIL.getHBaseCluster().killAll();
 
       // Still need to clean things up
       TEST_UTIL.shutdownMiniHBaseCluster();
     } finally {
       TEST_UTIL.getTestFileSystem().delete(FSUtils.getRootDir(TEST_UTIL.getConfiguration()), true);
       ZKUtil.deleteNodeRecursively(TEST_UTIL.getZooKeeperWatcher(), "/hbase");
     }
   }
 
   private ZooKeeperWatcher getZooKeeperWatcher(HConnection c)
   throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
     Method getterZK = c.getClass().getDeclaredMethod("getKeepAliveZooKeeperWatcher");
     getterZK.setAccessible(true);
     return (ZooKeeperWatcher) getterZK.invoke(c);
   }
 
 
   /**
    * See HBASE-1232 and http://wiki.apache.org/hadoop/ZooKeeper/FAQ#4.
    * @throws IOException
    * @throws InterruptedException
    */
   // fails frequently, disabled for now, see HBASE-6406
   @Ignore
   @Test
   public void testClientSessionExpired() throws Exception {
     Configuration c = new Configuration(TEST_UTIL.getConfiguration());
 
     // We don't want to share the connection as we will check its state
     c.set(HConstants.HBASE_CLIENT_INSTANCE_ID, "1111");
 
     HConnection connection = HConnectionManager.getConnection(c);
 
     ZooKeeperWatcher connectionZK = getZooKeeperWatcher(connection);
     LOG.info("ZooKeeperWatcher= 0x"+ Integer.toHexString(
       connectionZK.hashCode()));
     LOG.info("getRecoverableZooKeeper= 0x"+ Integer.toHexString(
       connectionZK.getRecoverableZooKeeper().hashCode()));
     LOG.info("session="+Long.toHexString(
       connectionZK.getRecoverableZooKeeper().getSessionId()));
 
     TEST_UTIL.expireSession(connectionZK);
 
     LOG.info("Before using zkw state=" +
       connectionZK.getRecoverableZooKeeper().getState());
     // provoke session expiration by doing something with ZK
     try {
       connectionZK.getRecoverableZooKeeper().getZooKeeper().exists(
         "/1/1", false);
     } catch (KeeperException ignored) {
     }
 
     // Check that the old ZK connection is closed, means we did expire
     States state = connectionZK.getRecoverableZooKeeper().getState();
     LOG.info("After using zkw state=" + state);
     LOG.info("session="+Long.toHexString(
       connectionZK.getRecoverableZooKeeper().getSessionId()));
 
     // It's asynchronous, so we may have to wait a little...
     final long limit1 = System.currentTimeMillis() + 3000;
     while (System.currentTimeMillis() < limit1 && state != States.CLOSED){
       state = connectionZK.getRecoverableZooKeeper().getState();
     }
     LOG.info("After using zkw loop=" + state);
     LOG.info("ZooKeeper should have timed out");
     LOG.info("session="+Long.toHexString(
       connectionZK.getRecoverableZooKeeper().getSessionId()));
 
     // It's surprising but sometimes we can still be in connected state.
     // As it's known (even if not understood) we don't make the the test fail
     // for this reason.)
     // Assert.assertTrue("state=" + state, state == States.CLOSED);
 
     // Check that the client recovered
     ZooKeeperWatcher newConnectionZK = getZooKeeperWatcher(connection);
 
     States state2 = newConnectionZK.getRecoverableZooKeeper().getState();
     LOG.info("After new get state=" +state2);
 
     // As it's an asynchronous event we may got the same ZKW, if it's not
     //  yet invalidated. Hence this loop.
     final long limit2 = System.currentTimeMillis() + 3000;
     while (System.currentTimeMillis() < limit2 &&
       state2 != States.CONNECTED && state2 != States.CONNECTING) {
 
       newConnectionZK = getZooKeeperWatcher(connection);
       state2 = newConnectionZK.getRecoverableZooKeeper().getState();
     }
     LOG.info("After new get state loop=" + state2);
 
     Assert.assertTrue(
       state2 == States.CONNECTED || state2 == States.CONNECTING);
 
     connection.close();
   }
 
   @Test (timeout = 120000)
   public void testRegionServerSessionExpired() throws Exception {
     LOG.info("Starting testRegionServerSessionExpired");
     TEST_UTIL.expireRegionServerSession(0);
     testSanity("testRegionServerSessionExpired");
   }
 
   @Test(timeout = 300000)
   public void testMasterSessionExpired() throws Exception {
     LOG.info("Starting testMasterSessionExpired");
     TEST_UTIL.expireMasterSession();
     testSanity("testMasterSessionExpired");
   }
 
   /**
    * Master recovery when the znode already exists. Internally, this
    *  test differs from {@link #testMasterSessionExpired} because here
    *  the master znode will exist in ZK.
    */
   @Test(timeout = 300000)
   public void testMasterZKSessionRecoveryFailure() throws Exception {
     LOG.info("Starting testMasterZKSessionRecoveryFailure");
     MiniHBaseCluster cluster = TEST_UTIL.getHBaseCluster();
     HMaster m = cluster.getMaster();
     m.abort("Test recovery from zk session expired",
         new KeeperException.SessionExpiredException());
     assertTrue(m.isStopped()); // Master doesn't recover any more
     testSanity("testMasterZKSessionRecoveryFailure");
   }
 
   /**
    * Make sure we can use the cluster
    * @throws Exception
    */
   private void testSanity(final String testName) throws Exception{
     String tableName = testName + "_" + System.currentTimeMillis();
     HTableDescriptor desc = new HTableDescriptor(TableName.valueOf(tableName));
     HColumnDescriptor family = new HColumnDescriptor("fam");
     desc.addFamily(family);
     LOG.info("Creating table " + tableName);
     Admin admin = TEST_UTIL.getHBaseAdmin();
     try {
       admin.createTable(desc);
     } finally {
       admin.close();
     }
 
     Table table =
       new HTable(new Configuration(TEST_UTIL.getConfiguration()), desc.getTableName());
     Put put = new Put(Bytes.toBytes("testrow"));
     put.add(Bytes.toBytes("fam"),
         Bytes.toBytes("col"), Bytes.toBytes("testdata"));
     LOG.info("Putting table " + tableName);
     table.put(put);
     table.close();
   }
 
   @Test
   public void testMultipleZK()
   throws IOException, NoSuchMethodException, InvocationTargetException, IllegalAccessException {
     Table localMeta =
       new HTable(new Configuration(TEST_UTIL.getConfiguration()), TableName.META_TABLE_NAME);
     Configuration otherConf = new Configuration(TEST_UTIL.getConfiguration());
     otherConf.set(HConstants.ZOOKEEPER_QUORUM, "127.0.0.1");
     Table ipMeta = new HTable(otherConf, TableName.META_TABLE_NAME);
 
     // dummy, just to open the connection
     final byte [] row = new byte [] {'r'};
     localMeta.exists(new Get(row));
     ipMeta.exists(new Get(row));
 
     // make sure they aren't the same
     ZooKeeperWatcher z1 =
       getZooKeeperWatcher(HConnectionManager.getConnection(localMeta.getConfiguration()));
     ZooKeeperWatcher z2 =
       getZooKeeperWatcher(HConnectionManager.getConnection(otherConf));
     assertFalse(z1 == z2);
     assertFalse(z1.getQuorum().equals(z2.getQuorum()));
 
     localMeta.close();
     ipMeta.close();
   }
 
   /**
    * Create a znode with data
    * @throws Exception
    */
   @Test
   public void testCreateWithParents() throws Exception {
     ZooKeeperWatcher zkw =
         new ZooKeeperWatcher(new Configuration(TEST_UTIL.getConfiguration()),
             TestZooKeeper.class.getName(), null);
     byte[] expectedData = new byte[] { 1, 2, 3 };
     ZKUtil.createWithParents(zkw, "/l1/l2/l3/l4/testCreateWithParents", expectedData);
     byte[] data = ZKUtil.getData(zkw, "/l1/l2/l3/l4/testCreateWithParents");
     assertTrue(Bytes.equals(expectedData, data));
     ZKUtil.deleteNodeRecursively(zkw, "/l1");
 
     ZKUtil.createWithParents(zkw, "/testCreateWithParents", expectedData);
     data = ZKUtil.getData(zkw, "/testCreateWithParents");
     assertTrue(Bytes.equals(expectedData, data));
     ZKUtil.deleteNodeRecursively(zkw, "/testCreateWithParents");
   }
 
   /**
    * Create a bunch of znodes in a hierarchy, try deleting one that has childs (it will fail), then
    * delete it recursively, then delete the last znode
    * @throws Exception
    */
   @Test
   public void testZNodeDeletes() throws Exception {
     ZooKeeperWatcher zkw = new ZooKeeperWatcher(
       new Configuration(TEST_UTIL.getConfiguration()),
       TestZooKeeper.class.getName(), null);
     ZKUtil.createWithParents(zkw, "/l1/l2/l3/l4");
     try {
       ZKUtil.deleteNode(zkw, "/l1/l2");
       fail("We should not be able to delete if znode has childs");
     } catch (KeeperException ex) {
       assertNotNull(ZKUtil.getDataNoWatch(zkw, "/l1/l2/l3/l4", null));
     }
     ZKUtil.deleteNodeRecursively(zkw, "/l1/l2");
     // make sure it really is deleted
     assertNull(ZKUtil.getDataNoWatch(zkw, "/l1/l2/l3/l4", null));
 
     // do the same delete again and make sure it doesn't crash
     ZKUtil.deleteNodeRecursively(zkw, "/l1/l2");
 
     ZKUtil.deleteNode(zkw, "/l1");
     assertNull(ZKUtil.getDataNoWatch(zkw, "/l1/l2", null));
   }
 
   /**
    * A test for HBASE-3238
    * @throws IOException A connection attempt to zk failed
    * @throws InterruptedException One of the non ZKUtil actions was interrupted
    * @throws KeeperException Any of the zookeeper connections had a
    * KeeperException
    */
   @Test
   public void testCreateSilentIsReallySilent() throws InterruptedException,
       KeeperException, IOException {
     Configuration c = TEST_UTIL.getConfiguration();
 
     String aclZnode = "/aclRoot";
     String quorumServers = ZKConfig.getZKQuorumServersString(c);
     int sessionTimeout = 5 * 1000; // 5 seconds
     ZooKeeper zk = new ZooKeeper(quorumServers, sessionTimeout, EmptyWatcher.instance);
     zk.addAuthInfo("digest", "hbase:rox".getBytes());
 
     // Assumes the  root of the ZooKeeper space is writable as it creates a node
     // wherever the cluster home is defined.
     ZooKeeperWatcher zk2 = new ZooKeeperWatcher(TEST_UTIL.getConfiguration(),
       "testCreateSilentIsReallySilent", null);
 
     // Save the previous ACL
     Stat s =  null;
     List<ACL> oldACL = null;
     while (true) {
       try {
         s = new Stat();
         oldACL = zk.getACL("/", s);
         break;
       } catch (KeeperException e) {
         switch (e.code()) {
           case CONNECTIONLOSS:
           case SESSIONEXPIRED:
           case OPERATIONTIMEOUT:
             LOG.warn("Possibly transient ZooKeeper exception", e);
             Threads.sleep(100);
             break;
          default:
             throw e;
         }
       }
     }
 
     // I set this acl after the attempted creation of the cluster home node.
     // Add retries in case of retryable zk exceptions.
     while (true) {
       try {
         zk.setACL("/", ZooDefs.Ids.CREATOR_ALL_ACL, -1);
         break;
       } catch (KeeperException e) {
         switch (e.code()) {
           case CONNECTIONLOSS:
           case SESSIONEXPIRED:
           case OPERATIONTIMEOUT:
             LOG.warn("Possibly transient ZooKeeper exception: " + e);
             Threads.sleep(100);
             break;
          default:
             throw e;
         }
       }
     }
 
     while (true) {
       try {
         zk.create(aclZnode, null, ZooDefs.Ids.CREATOR_ALL_ACL, CreateMode.PERSISTENT);
         break;
       } catch (KeeperException e) {
         switch (e.code()) {
           case CONNECTIONLOSS:
           case SESSIONEXPIRED:
           case OPERATIONTIMEOUT:
             LOG.warn("Possibly transient ZooKeeper exception: " + e);
             Threads.sleep(100);
             break;
          default:
             throw e;
         }
       }
     }
     zk.close();
     ZKUtil.createAndFailSilent(zk2, aclZnode);
 
     // Restore the ACL
     ZooKeeper zk3 = new ZooKeeper(quorumServers, sessionTimeout, EmptyWatcher.instance);
     zk3.addAuthInfo("digest", "hbase:rox".getBytes());
     try {
       zk3.setACL("/", oldACL, -1);
     } finally {
       zk3.close();
     }
  }
 
   /**
    * Test should not fail with NPE when getChildDataAndWatchForNewChildren
    * invoked with wrongNode
    */
   @Test
   @SuppressWarnings("deprecation")
   public void testGetChildDataAndWatchForNewChildrenShouldNotThrowNPE()
       throws Exception {
     ZooKeeperWatcher zkw = new ZooKeeperWatcher(TEST_UTIL.getConfiguration(),
         "testGetChildDataAndWatchForNewChildrenShouldNotThrowNPE", null);
     ZKUtil.getChildDataAndWatchForNewChildren(zkw, "/wrongNode");
   }
 
   /**
    * Tests that the master does not call retainAssignment after recovery from expired zookeeper
    * session. Without the HBASE-6046 fix master always tries to assign all the user regions by
    * calling retainAssignment.
    */
   @Test(timeout = 300000)
   public void testRegionAssignmentAfterMasterRecoveryDueToZKExpiry() throws Exception {
     MiniHBaseCluster cluster = TEST_UTIL.getHBaseCluster();
     cluster.startRegionServer();
     cluster.waitForActiveAndReadyMaster(10000);
     HMaster m = cluster.getMaster();
     final ZooKeeperWatcher zkw = m.getZooKeeper();
     // now the cluster is up. So assign some regions.
     try (Admin admin = TEST_UTIL.getHBaseAdmin()) {
       byte[][] SPLIT_KEYS = new byte[][] { Bytes.toBytes("a"), Bytes.toBytes("b"),
           Bytes.toBytes("c"), Bytes.toBytes("d"), Bytes.toBytes("e"), Bytes.toBytes("f"),
           Bytes.toBytes("g"), Bytes.toBytes("h"), Bytes.toBytes("i"), Bytes.toBytes("j") };
       String tableName = "testRegionAssignmentAfterMasterRecoveryDueToZKExpiry";
       HTableDescriptor htd = new HTableDescriptor(TableName.valueOf(tableName));
       htd.addFamily(new HColumnDescriptor(HConstants.CATALOG_FAMILY));
       admin.createTable(htd, SPLIT_KEYS);
       TEST_UTIL.waitUntilNoRegionsInTransition(60000);
       m.getZooKeeper().close();
       MockLoadBalancer.retainAssignCalled = false;
       final int expectedNumOfListeners = countPermanentListeners(zkw);
       m.abort("Test recovery from zk session expired",
           new KeeperException.SessionExpiredException());
       assertTrue(m.isStopped()); // Master doesn't recover any more
       // The recovered master should not call retainAssignment, as it is not a
       // clean startup.
       assertFalse("Retain assignment should not be called", MockLoadBalancer.retainAssignCalled);
       // number of listeners should be same as the value before master aborted
       // wait for new master is initialized
       cluster.waitForActiveAndReadyMaster(120000);
       final HMaster newMaster = cluster.getMasterThread().getMaster();
       assertEquals(expectedNumOfListeners, countPermanentListeners(newMaster.getZooKeeper()));
     }
   }
 
   /**
    * Count listeners in zkw excluding listeners, that belongs to workers or other
    * temporary processes.
    */
   private int countPermanentListeners(ZooKeeperWatcher watcher) {
     return countListeners(watcher, ZkSplitLogWorkerCoordination.class);
   }
 
   /**
    * Count listeners in zkw excluding provided classes
    */
   private int countListeners(ZooKeeperWatcher watcher, Class<?>... exclude) {
     int cnt = 0;
     for (Object o : watcher.getListeners()) {
       boolean skip = false;
       for (Class<?> aClass : exclude) {
         if (aClass.isAssignableFrom(o.getClass())) {
           skip = true;
           break;
         }
       }
       if (!skip) {
         cnt += 1;
       }
     }
     return cnt;
   }
 
 
   /**
    * Tests whether the logs are split when master recovers from a expired zookeeper session and an
    * RS goes down.
    */
   @Test(timeout = 300000)
   public void testLogSplittingAfterMasterRecoveryDueToZKExpiry() throws IOException,
       KeeperException, InterruptedException {
     MiniHBaseCluster cluster = TEST_UTIL.getHBaseCluster();
     cluster.startRegionServer();
     HMaster m = cluster.getMaster();
     // now the cluster is up. So assign some regions.
     Admin admin = TEST_UTIL.getHBaseAdmin();
     Table table = null;
     try {
       byte[][] SPLIT_KEYS = new byte[][] { Bytes.toBytes("1"), Bytes.toBytes("2"),
         Bytes.toBytes("3"), Bytes.toBytes("4"), Bytes.toBytes("5") };
 
       String tableName = "testLogSplittingAfterMasterRecoveryDueToZKExpiry";
       HTableDescriptor htd = new HTableDescriptor(TableName.valueOf(tableName));
       HColumnDescriptor hcd = new HColumnDescriptor("col");
       htd.addFamily(hcd);
       admin.createTable(htd, SPLIT_KEYS);
       ZooKeeperWatcher zooKeeperWatcher = HBaseTestingUtility.getZooKeeperWatcher(TEST_UTIL);
       ZKAssign.blockUntilNoRIT(zooKeeperWatcher);
       table = new HTable(TEST_UTIL.getConfiguration(), htd.getTableName());
       Put p;
       int numberOfPuts;
       for (numberOfPuts = 0; numberOfPuts < 6; numberOfPuts++) {
         p = new Put(Bytes.toBytes(numberOfPuts));
         p.add(Bytes.toBytes("col"), Bytes.toBytes("ql"), Bytes.toBytes("value" + numberOfPuts));
         table.put(p);
       }
       m.getZooKeeper().close();
       m.abort("Test recovery from zk session expired",
         new KeeperException.SessionExpiredException());
       assertTrue(m.isStopped()); // Master doesn't recover any more
       cluster.getRegionServer(0).abort("Aborting");
       // Without patch for HBASE-6046 this test case will always timeout
       // with patch the test case should pass.
       Scan scan = new Scan();
       int numberOfRows = 0;
       ResultScanner scanner = table.getScanner(scan);
       Result[] result = scanner.next(1);
       while (result != null && result.length > 0) {
         numberOfRows++;
         result = scanner.next(1);
       }
       assertEquals("Number of rows should be equal to number of puts.", numberOfPuts,
         numberOfRows);
     } finally {
       if (table != null) table.close();
       admin.close();
     }
   }
 
   static class MockLoadBalancer extends SimpleLoadBalancer {
     static boolean retainAssignCalled = false;
 
     @Override
     public Map<ServerName, List<HRegionInfo>> retainAssignment(
         Map<HRegionInfo, ServerName> regions, List<ServerName> servers) {
       retainAssignCalled = true;
       return super.retainAssignment(regions, servers);
     }
   }
 
 }