HBASE-24525 [branch-1] Support ZooKeeper 3.6.0+ (#1879)

Signed-off-by: Bharath Vissapragada <bharathv@apache.org>

hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/HQuorumPeer.java

@@ -85,14 +85,26 @@ public class HQuorumPeer {
   }
 
   private static void runZKServer(QuorumPeerConfig zkConfig) throws UnknownHostException, IOException {
-    if (zkConfig.isDistributed()) {
-      QuorumPeerMain qp = new QuorumPeerMain();
-      qp.runFromConfig(zkConfig);
-    } else {
-      ZooKeeperServerMain zk = new ZooKeeperServerMain();
-      ServerConfig serverConfig = new ServerConfig();
-      serverConfig.readFrom(zkConfig);
-      zk.runFromConfig(serverConfig);
+    try {
+      if (zkConfig.isDistributed()) {
+        QuorumPeerMain qp = new QuorumPeerMain();
+        qp.runFromConfig(zkConfig);
+      } else {
+        ZooKeeperServerMain zk = new ZooKeeperServerMain();
+        ServerConfig serverConfig = new ServerConfig();
+        serverConfig.readFrom(zkConfig);
+        zk.runFromConfig(serverConfig);
+      }
+    } catch (UnknownHostException e) {
+      throw e;
+    } catch (Exception e) {
+      // The current signature proposes we throw IOException or
+      // UnknownHostException. ZK 3.6 throws another type of checked
+      // exception, which causes a compilation error. Therefore we catch
+      // that and potentially others, and wrap it into an IOE. Adding a
+      // new checked exception to the signature would cause a compilation 
+      // problem with 3.4.
+      throw new IOException(e);
     }
   }
 

hbase-client/src/main/java/org/apache/hadoop/hbase/zookeeper/ZKUtil.java

@@ -1811,9 +1811,10 @@ public class ZKUtil {
    */
   public static void multiOrSequential(ZooKeeperWatcher zkw, List<ZKUtilOp> ops,
       boolean runSequentialOnMultiFailure) throws KeeperException {
-    if (ops == null) return;
+    if (ops == null || ops.isEmpty()) {
+      return;
+    }
     boolean useMulti = zkw.getConfiguration().getBoolean(HConstants.ZOOKEEPER_USEMULTI, false);
-
     if (useMulti) {
       List<Op> zkOps = new LinkedList<Op>();
       for (ZKUtilOp op : ops) {
@@ -1846,7 +1847,6 @@ public class ZKUtil {
       // run sequentially
       processSequentially(zkw, ops);
     }
-
   }
 
   private static void processSequentially(ZooKeeperWatcher zkw, List<ZKUtilOp> ops)

hbase-server/src/main/jamon/org/apache/hadoop/hbase/tmpl/master/MasterStatusTmpl.jamon

@@ -294,7 +294,7 @@ AssignmentManager assignmentManager = master.getAssignmentManager();
                 </tr>
                 <tr>
                     <td>ZooKeeper Client Version</td>
-                    <td><% org.apache.zookeeper.Version.getVersion() %>, revision=<% org.apache.zookeeper.Version.getRevision() %></td>
+                    <td><% org.apache.zookeeper.Version.getVersion() %></td>
                     <td>ZooKeeper client version and revision</td>
                 </tr>
                 <tr>

hbase-server/src/main/jamon/org/apache/hadoop/hbase/tmpl/regionserver/RSStatusTmpl.jamon

@@ -168,7 +168,7 @@ org.apache.hadoop.hbase.zookeeper.MasterAddressTracker;
         </tr>
         <tr>
             <td>ZooKeeper Client Version</td>
-            <td><% org.apache.zookeeper.Version.getVersion() %>, revision=<% org.apache.zookeeper.Version.getRevision() %></td>
+            <td><% org.apache.zookeeper.Version.getVersion() %></td>
             <td>ZooKeeper client version and revision</td>
         </tr>
         <tr>

hbase-server/src/main/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperMainServer.java

@@ -66,8 +66,20 @@ public class ZooKeeperMainServer {
      * @throws IOException
      * @throws InterruptedException
      */
-    void runCmdLine() throws KeeperException, IOException, InterruptedException {
-      processCmd(this.cl);
+    void runCmdLine() throws IOException, InterruptedException {
+      try {
+        processCmd(this.cl);
+      } catch (IOException | InterruptedException e) {
+        throw e;
+      } catch (Exception e) {
+        // The current signature proposes we throw IOException or
+        // InterruptedException. ZK 3.6 throws another type of checked
+        // exception, which causes a compilation error. Therefore we catch
+        // that and potentially others, and wrap it into an IOE. Adding a
+        // new checked exception to the signature would cause a compilation 
+        // problem with 3.4.
+        throw new IOException(e);
+      }
       System.exit(0);
     }
   }

hbase-server/src/test/java/org/apache/hadoop/hbase/zookeeper/TestHQuorumPeer.java

@@ -21,6 +21,9 @@ package org.apache.hadoop.hbase.zookeeper;
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.net.InetSocketAddress;
 import java.util.Map;
 import java.util.Properties;
 
@@ -111,25 +114,45 @@ public class TestHQuorumPeer {
     QuorumPeerConfig config = new QuorumPeerConfig();
     config.parseProperties(properties);
 
-    assertEquals(this.dataDir.toString(), config.getDataDir());
+    assertEquals(this.dataDir.toString(), config.getDataDir().toString());
     assertEquals(2181, config.getClientPortAddress().getPort());
     Map<Long,QuorumServer> servers = config.getServers();
     assertEquals(3, servers.size());
     assertTrue(servers.containsKey(Long.valueOf(0)));
     QuorumServer server = servers.get(Long.valueOf(0));
-    assertEquals("localhost", server.addr.getHostName());
+    assertEquals("localhost", getHostName(server));
 
     // Override with system property.
     System.setProperty("hbase.master.hostname", "foo.bar");
     is = new ByteArrayInputStream(s.getBytes());
     properties = ZKConfig.parseZooCfg(conf, is);
     assertEquals("foo.bar:2888:3888", properties.get("server.0"));
-
     config.parseProperties(properties);
 
     servers = config.getServers();
     server = servers.get(Long.valueOf(0));
-    assertEquals("foo.bar", server.addr.getHostName());
+    assertEquals("foo.bar", getHostName(server));
+  }
+
+  // The reflection in this method is needed to smooth over internal differences
+  // between ZK 3.4 and 3.6. The type of 'addr' in 3.4 is InetSocketAddress. In
+  // 3.6 it becomes org.apache.zookeeper.server.quorum.MultipleAddresses, a set
+  // of InetSocketAddress.
+  private static String getHostName(QuorumServer server) throws Exception {
+    String hostname;
+    switch (server.addr.getClass().getName()) {
+      case "org.apache.zookeeper.server.quorum.MultipleAddresses":
+        // ZK 3.6 and up
+        Method m = server.addr.getClass().getDeclaredMethod("getOne");
+        hostname = ((InetSocketAddress)m.invoke(server.addr)).getHostName();
+        break;
+      default:
+        // ZK <= 3.5
+        Field f = server.getClass().getField("addr");
+        hostname = ((InetSocketAddress)f.get(server)).getHostName();
+        break;
+    }
+    return hostname;
   }
 
   @Test public void testShouldAssignDefaultZookeeperClientPort() {