hadoop ha 读取 activce状态的活动节点

 方式一

package com.xxx.hadoop;

import com.sun.demo.jvmti.hprof.Tracker;
import com.sun.xml.bind.util.Which;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.HAUtil;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.lang.reflect.WildcardType;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.List;

/**
 * @Desription:
 * @CreatedDate: 2018/1/5 10:01
 * @Author：wangel.lee
 */
public class TestNodeActive {
    public static void main(String[] args) throws IOException {
        getActiveNameNode();
    }

    /**
     * 判断hadoop ha的active节点是否存活
     * @throws IOException
     */
    public static void getActiveNameNode() throws IOException {
        String[] mapredJopTrackers = {"hdfs://10.1.1.12:8030","hdfs://10.1.1.11:8030"};
        String[] fsDefaultNames = {"hdfs://10.1.1.12:8020","hdfs://10.1.1.11:8020"};

        String hivePath = "";
        for (int i = 0 ;i <2 ; i++) {
            Configuration conf = createConfigurationDefault(mapredJopTrackers[i],fsDefaultNames[i]);
            // 远程会出现问题 Windows测试需要如下配置
            List<String> data = new ArrayList<String>();
            FileSystem fileSystem = FileSystem.get(conf);
            InetSocketAddress active = null;
            try {
                active = HAUtil.getAddressOfActive(fileSystem);
            } catch ( Exception e ){
                System.out.println("hostname："+mapredJopTrackers[i]+" is not active.");
            }
            if( active == null ) continue;
            InetAddress address = active.getAddress();
            hivePath = "hdfs://" + address.getHostAddress() + ":" + active.getPort();
            break;
        }
        System.out.println(hivePath);
    }

    private static Configuration createConfigurationDefault(String mapredJopTracker, String fsDefaultName) throws IOException {
        Configuration conf = new Configuration();
        // 远程会出现问题 Windows测试需要如下配置
        conf.set("mapred.jop.tracker", mapredJopTracker);
        conf.set("fs.default.name", fsDefaultName);
        System.setProperty("hadoop.home.dir", "E:\ProgramFiles\java\hadoop\hadoop-common-2.2.0-bin-master");

        return conf;
    }
}

方式二

package com.yanheap.hadoop;


import com.alibaba.druid.util.StringUtils;
import org.apache.commons.io.FileUtils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hdfs.HAUtil;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.URI;
import java.util.ArrayList;
import java.util.List;

/**
 * @Desription:
 * @CreatedDate: 2018/1/5 14:48
 * @Author：wangel.lee
 */
public class ZookeeperActive {

    private static String clusterName = "nameservice1";
    private static final String HADOOP_URL = "hdfs://"+clusterName;
    private static Configuration conf;
    static{
        conf = new Configuration();
        conf = new Configuration();
        conf.set("fs.defaultFS", HADOOP_URL);
        conf.set("dfs.nameservices", clusterName);
        conf.set("dfs.ha.namenodes."+clusterName, "nn1,nn2");
        // 高可用的配置：当其中一个变成standy时，打印异常，并自动切换到另一个namedata去取数据
        conf.set("dfs.namenode.rpc-address."+clusterName+".nn1", "10.1.1.12:8020");
        conf.set("dfs.namenode.rpc-address."+clusterName+".nn2", "10.1.1.11:8020");
        //conf.setBoolean(name, value);
        conf.set("dfs.client.failover.proxy.provider."+clusterName,
                "org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider");
    }

    /**
     * 读取ha的active节点
     * @throws IOException
     */
    private static void getActive() throws IOException {
        FileSystem fileSystem = FileSystem.get(URI.create(HADOOP_URL), conf);

        long l1 = System.currentTimeMillis();

        InetSocketAddress active = null;
        //try {
            active = HAUtil.getAddressOfActive(fileSystem);
        //} catch ( Exception e ){
            //e.printStackTrace();
        //}
        InetAddress address = active.getAddress();
        String hivePath = "hdfs://" + address.getHostAddress() + ":" + active.getPort();

        System.out.println("-------------------------------------->"+hivePath);
        System.out.println("-------------------------------------->"+(System.currentTimeMillis()-l1));
    }


    /**
     * 读取hdfs中的文件
     * @throws IOException
     */
    private static void readFile() throws IOException {
        FileSystem fileSystem = FileSystem.get(URI.create(HADOOP_URL), conf);
        FSDataInputStream in = null;
        BufferedReader br = null;

        try {
            fileSystem = FileSystem.get(conf);
            Path srcPath = new Path("/tmp/media_info.csv");
            in = fileSystem.open(srcPath);
            br = new BufferedReader(new InputStreamReader(in));
            String line = null;
            while (null != (line = br.readLine())) {
                if (!StringUtils.isEmpty(line)) {
                    System.out.println("-------->:"+line);
                }
            }
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (Exception e) {
            throw e;
        } finally {
            br.close();
            fileSystem.close();
        }

    }

    public static void main(String[] args)throws IOException  {
        //getActive();
        readFile();
    }

}

另，本地windows执行hadoop需要环境变量的支持，如下提供hadoop命令下载包，下载后直接添加环境变量对他的引用

链接：https://pan.baidu.com/s/1eRIHmdO 密码：ly38