ZOOKEEPER集群搭建及测试

     ①. zk是由java编写的须要java运行环境,因此你们首先要安装JDK

具体安装步骤,再也不赘述

     ②. 首先进入zk的conf目录,将zoo_sample.cfg文件更名为zoo.cfg,并修改内容

tickTime=2000 #ZK中的一个时间单元。ZK中全部时间都是以这个时间单元为基础，进行整数倍配置的。例如，session的最小超时时间是2*tickTime。
initLimit=5 #Leader容许Follower在 initLimit 时间内完成这个工做
syncLimit=2 #心跳检测,Leader发出心跳包在syncLimit以后，尚未从F那里收到响应，那么就认为这个F已经不在线了
dataDir=/usr/local/zookeeper/data #咱们须要在此目录下建立myid用于标识zk节点,对应server.x,事务日志也会存储在这里
dataLogDir=/usr/local/zookeeper/logs #事务日志输出目录
clientPort=2181 #对外提供的端口号,默认2181
server.1=zk1:2888:3888 #server.x跟myid对应,两个通讯端口第一个端口用于F和L之间的数据同步和其它通讯，第二个端口用于Leader选举过程当中投票通讯。
server.2=zk2:2888:3888
server.3=zk3:2888:3888

      ③. 设置myid, 在zk根目录建立前面zoo.cfg中配置的dataDir指定的文件夹,建立myid,myid中的值需与server.x保持一致

    ④. 都设置完以后,记得检查一下各节点端口是否打通,而且关闭防火墙

     ⑤. 进入bin目录,执行 sh zkServer.sh start &  命令,经过JPS检查是否启动,而且查看日志:

  tail -fn 100 zookeeper.out,第一个节点启动,会报以下异常:

此时不作理会,当全部节点启动完成以后即恢复正常

2017-09-14 14:50:24,993 [myid:2] - INFO  [QuorumPeer[myid=2]/0:0:0:0:0:0:0:0:2181:QuorumPeer$QuorumServer@149] - Resolved hostname: 192.168.116.127 to address: /zk2
2017-09-14 14:50:24,995 [myid:2] - WARN  [QuorumPeer[myid=2]/0:0:0:0:0:0:0:0:2181:QuorumCnxManager@400] - Cannot open channel to 3 at election address /zk2:3888
java.net.ConnectException: 拒绝链接
	at java.net.PlainSocketImpl.socketConnect(Native Method)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
	at java.net.Socket.connect(Socket.java:579)
	at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:381)
	at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectAll(QuorumCnxManager.java:426)
	at org.apache.zookeeper.server.quorum.FastLeaderElection.lookForLeader(FastLeaderElection.java:843)
	at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:822)

,使用 sh zkServer.sh status检查节点状态,通常myid大的为leader

    客户端验证是否成功:

private final static String CONNECT_STRING = "zk1:2181,zk2:2181,zk3:2181";
	private final static int SESSION_TIMEOUT = 2000;
	private ZooKeeper zk = null;

	@Before
	public void init() throws Exception {
		zk = new ZooKeeper(CONNECT_STRING, SESSION_TIMEOUT, new ZKWatcher());
	}

	@Test
	public void create() throws Exception {
		String cResponse = zk.create("/app-01", "hello this is app-01 node".getBytes(),
		        Ids.OPEN_ACL_UNSAFE,
		        CreateMode.PERSISTENT);
		Thread.sleep(1000);
		System.out.println("--->create:" + cResponse);
	}

	@Test
	public void get() throws Exception {
		System.out.println(zk.getChildren("/", new ZKWatcher()));
	}

	@Test
	public void set() throws Exception {
		System.out.println(zk.setData("/app-01", "this is app-01 node.update count 4".getBytes(), -1));
	}

	@Test
	public void getData() throws Exception {
		System.out.println(new String(zk.getData("/app-01/hello", new ZKWatcher(), null)));
//		Thread.sleep(Long.MAX_VALUE);
	}

或使用工具:ZooInspector链接,检查使用状况以及服务端状态