第五步：启动ZooKeeper集群
在ZooKeeper集群的每个结点上，执行启动ZooKeeper服务的脚本，如下所示：
Hadoop@slave-01:~/installation/zookeeper-3.3.4$ bin/zkServer.sh start hadoop@slave-02:~/installation/zookeeper-3.3.4$ bin/zkServer.sh start hadoop@slave-03:~/installation/zookeeper-3.3.4$ bin/zkServer.sh start
以结点slave-01为例，日志如下所示：hadoop@slave-01:~/installation/zookeeper-3.3.4$ tail -500f zookeeper.out 2012-01-08 06:51:19,117 - INFO [main:QuorumPeerConfig@90] - Reading configuration from: /home/hadoop/installation/zookeeper-3.3.4/bin/../conf/zoo.cfg 2012-01-08 06:51:19,133 - INFO [main:QuorumPeerConfig@310] - Defaulting to majority quorums 2012-01-08 06:51:19,167 - INFO [main:QuorumPeerMain@119] - Starting quorum peer 2012-01-08 06:51:19,227 - INFO [main:NIOServerCnxn$Factory@143] - binding to port 0.0.0.0/0.0.0.0:2181 2012-01-08 06:51:19,277 - INFO [main:QuorumPeer@819] - tickTime set to 2000 2012-01-08 06:51:19,278 - INFO [main:QuorumPeer@830] - minSessionTimeout set to -1 2012-01-08 06:51:19,279 - INFO [main:QuorumPeer@841] - maxSessionTimeout set to -1 2012-01-08 06:51:19,281 - INFO [main:QuorumPeer@856] - initLimit set to 5 2012-01-08 06:51:19,347 - INFO [Thread-1:QuorumCnxManager$Listener@473] - My election bind port: 3888 2012-01-08 06:51:19,393 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumPeer@621] - LOOKING 2012-01-08 06:51:19,396 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@663] - New election. My id = 1, Proposed zxid = 0 2012-01-08 06:51:19,400 - INFO [WorkerReceiver Thread:FastLeaderElection@496] - Notification: 1 (n.leader), 0 (n.zxid), 1 (n.round), LOOKING (n.state), 1 (n.sid), LOOKING (my state) 2012-01-08 06:51:19,416 - WARN [WorkerSender Thread:QuorumCnxManager@384] - Cannot open channel to 2 at election address slave-02/192.168.0.178:3888 Java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371) at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:340) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333) at java.lang.Thread.run(Thread.java:662) 2012-01-08 06:51:19,420 - WARN [WorkerSender Thread:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888 java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371) at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:340) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333) at java.lang.Thread.run(Thread.java:662) 2012-01-08 06:51:19,612 - WARN [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 2 at election address slave-02/192.168.0.178:3888 java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404) at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688) at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622) 2012-01-08 06:51:19,615 - WARN [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888 java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404) at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688) at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622) 2012-01-08 06:51:19,616 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 400 2012-01-08 06:51:20,019 - WARN [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 2 at election address slave-02/192.168.0.178:3888 java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404) at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688) at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622) 2012-01-08 06:51:20,021 - WARN [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888 java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404) at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688) at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622) 2012-01-08 06:51:20,022 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 800 2012-01-08 06:51:20,825 - WARN [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 2 at election address slave-02/192.168.0.178:3888 java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404) at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688) at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622) 2012-01-08 06:51:20,827 - WARN [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888 java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404) at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688) at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622) 2012-01-08 06:51:20,828 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 1600 2012-01-08 06:51:22,435 - WARN [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 2 at election address slave-02/192.168.0.178:3888 java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404) at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688) at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622) 2012-01-08 06:51:22,439 - WARN [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888 java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:404) at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:688) at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:622) 2012-01-08 06:51:22,441 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@697] - Notification time out: 3200 2012-01-08 06:51:22,945 - INFO [WorkerReceiver Thread:FastLeaderElection@496] - Notification: 2 (n.leader), 0 (n.zxid), 1 (n.round), LOOKING (n.state), 2 (n.sid), LOOKING (my state) 2012-01-08 06:51:22,946 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FastLeaderElection@721] - Updating proposal 2012-01-08 06:51:22,949 - WARN [WorkerSender Thread:QuorumCnxManager@384] - Cannot open channel to 3 at election address slave-03/192.168.0.177:3888 java.net.ConnectException: Connection refused at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method) at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:567) at sun.nio.ch.SocketAdaptor.connect(SocketAdaptor.java:100) at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:371) at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:340) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:360) at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:333) at java.lang.Thread.run(Thread.java:662) 2012-01-08 06:51:22,951 - INFO [WorkerReceiver Thread:FastLeaderElection@496] - Notification: 2 (n.leader), 0 (n.zxid), 1 (n.round), LOOKING (n.state), 1 (n.sid), LOOKING (my state) 2012-01-08 06:51:23,156 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:QuorumPeer@643] - FOLLOWING 2012-01-08 06:51:23,170 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Learner@80] - TCP NoDelay set to: true 2012-01-08 06:51:23,206 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:zookeeper.version=3.3.3-1203054, built on 11/17/2011 05:47 GMT 2012-01-08 06:51:23,207 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:host.name=slave-01 2012-01-08 06:51:23,207 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.version=1.6.0_30 2012-01-08 06:51:23,208 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.vendor=Sun Microsystems Inc. 2012-01-08 06:51:23,208 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.home=/home/hadoop/installation/jdk1.6.0_30/jre 2012-01-08 06:51:23,209 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.class.path=/home/hadoop/installation/zookeeper-3.3.4/bin/../build/classes:/home/hadoop/installation/zookeeper-3.3.4/bin/../build/lib/*.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../zookeeper-3.3.4.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/log4j-1.2.15.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/jline-0.9.94.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/commons-lang-2.4.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/commons-collections-3.2.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/commons-cli-1.1.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/apache-rat-tasks-0.6.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../lib/apache-rat-core-0.6.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../src/java/lib/*.jar:/home/hadoop/installation/zookeeper-3.3.4/bin/../conf:/home/hadoop/installation/jdk1.6.0_30/lib/*.jar:/home/hadoop/installation/jdk1.6.0_30/jre/lib/*.jar 2012-01-08 06:51:23,210 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.library.path=/home/hadoop/installation/jdk1.6.0_30/jre/lib/i386/client:/home/hadoop/installation/jdk1.6.0_30/jre/lib/i386:/home/hadoop/installation/jdk1.6.0_30/jre/../lib/i386:/usr/java/packages/lib/i386:/lib:/usr/lib 2012-01-08 06:51:23,210 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.io.tmpdir=/tmp 2012-01-08 06:51:23,212 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:java.compiler=<NA> 2012-01-08 06:51:23,212 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:os.name=Linux 2012-01-08 06:51:23,212 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:os.arch=i386 2012-01-08 06:51:23,213 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:os.version=3.0.0-14-generic 2012-01-08 06:51:23,213 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:user.name=hadoop 2012-01-08 06:51:23,214 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:user.home=/home/hadoop 2012-01-08 06:51:23,214 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Environment@97] - Server environment:user.dir=/home/hadoop/installation/zookeeper-3.3.4 2012-01-08 06:51:23,223 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:ZooKeeperServer@151] - Created server with tickTime 2000 minSessionTimeout 4000 maxSessionTimeout 40000 datadir /home/hadoop/storage/zookeeper/version-2 snapdir /home/hadoop/storage/zookeeper/version-2 2012-01-08 06:51:23,339 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Learner@294] - Getting a snapshot from leader 2012-01-08 06:51:23,358 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:Learner@325] - Setting leader epoch 1 2012-01-08 06:51:23,358 - INFO [QuorumPeer:/0:0:0:0:0:0:0:0:2181:FileTxnSnapLog@254] - Snapshotting: 0 2012-01-08 06:51:25,511 - INFO [WorkerReceiver Thread:FastLeaderElection@496] - Notification: 3 (n.leader), 0 (n.zxid), 1 (n.round), LOOKING (n.state), 3 (n.sid), FOLLOWING (my state) 2012-01-08 06:51:42,584 - INFO [WorkerReceiver Thread:FastLeaderElection@496] - Notification: 3 (n.leader), 0 (n.zxid), 2 (n.round), LOOKING (n.state), 3 (n.sid), FOLLOWING (my state)
我启动的顺序是slave-01>slave-02>slave-03，由于ZooKeeper集群启动的时候，每个结点都试图去连接集群中的其它结点，先启动的肯定连不上后面还没启动的，所以上面日志前面部分的异常是可以忽略的。通过后面部分可以看到，集群在选出一个Leader后，最后稳定了。其他结点可能也出现类似问题，属于正常。