通过Java代码获取Zookeeper服务器状态

有的时候，我们想知道Zookeeper集群中哪些服务器属于Leader，哪些属于Follower，哪些属于Observer。

通过命令，可以很容易的获取到Zookeeper服务器的状态：

 

[hadoop@hadoopcluster84 bin]$ ./zkServer.sh status
JMX enabled by default
Using config: /home/hadoop/apache/zookeeper-3.4.5/bin/../conf/zoo.cfg
Mode: follower

下面我们用Java代码来获取Zookeeper服务器的状态：

 

 

public class ServerStatus {
	@Test
	public void serverStatus() throws IOException {
		String host = "10.0.1.84";
		int port = 2181;
		String cmd = "stat";

		Socket sock = new Socket(host, port);
		BufferedReader reader = null;
		try {
			OutputStream outstream = sock.getOutputStream();
			// 通过Zookeeper的四字命令获取服务器的状态
			outstream.write(cmd.getBytes());
			outstream.flush();
			sock.shutdownOutput();

			reader = new BufferedReader(new InputStreamReader(sock.getInputStream()));
			String line;
			while ((line = reader.readLine()) != null) {
				if (line.indexOf("Mode: ") != -1) {
					System.out.println(line.replaceAll("Mode: ", "").trim());
				}
			}
		} finally {
			sock.close();
			if (reader != null) {
				reader.close();
			}
		}
	}
}

输出结果：

 

 

follower

上面的代码可以改改，通过其他四字命令获取zookeeper集群的状态。