如何查看hadoop 是否启动 检查hadoop进程是否存在

1、检查hadhoop进程是否启动：/usr/jdk1.7.0_51/bin/jps， masters上看到如下显示：
      ubuntu@ubuntu-K50ID:~/hadoop-1.2.1$ /usr/jdk1.7.0_51/bin/jps
      25174 SecondaryNameNode
      25263 JobTracker
      25366 Jps
      24911 NameNode
      slaves上看到：
      ubuntu@ubuntu1-VirtualBox:~/hadoop-1.2.1$ /usr/jdk1.7.0_51/bin/jps
      5643 DataNode
      5834 TaskTracker
      5880 Jps

2、在/home/ubuntu目录下创建文件夹input，在input目录下生成2个测试文件。
       mkdir input
       echo "hello world" >test1.txt
       echo "hello hadoop" >test2.txt
       在/home/ubuntu目录下执行命令（可以在其他目录执行，但是参数input目录必须设置正确）：
       /home/ubuntu/hadoop-1.2.1/bin/hadoop  fs -put input ./in
       察看in目录下文件情况：

ubuntu@ubuntu-K50ID:~$ /home/ubuntu/hadoop-1.2.1/bin/hadoop fs -ls ./in/ 

        Found 3 items 

        drwxr-xr-x   - ubuntu supergroup          0 2014-03-08 11:46 /user/ubuntu/in/input 

        -rw-r--r--   1 ubuntu supergroup         12 2014-02-17 20:56 /user/ubuntu/in/test1.txt 

        -rw-r--r--   1 ubuntu supergroup         13 2014-02-17 20:56 /user/ubuntu/in/test2.txt

3、测试统计in目录下的文件中各单词数目，命令如下：
   

ubuntu@ubuntu-K50ID:~/hadoop-1.2.1$ bin/hadoop jar hadoop-examples-1.2.1.jar wordcount in out 

       14/03/08 12:01:39 INFO input.FileInputFormat: Total input paths to process : 2 

       14/03/08 12:01:39 INFO util.NativeCodeLoader: Loaded the native-hadoop library 

       14/03/08 12:01:39 WARN snappy.LoadSnappy: Snappy native library not loaded 

       14/03/08 12:01:40 INFO mapred.JobClient: Running job: job_201403081130_0004 

       14/03/08 12:01:41 INFO mapred.JobClient:  map 0% reduce 0% 

       14/03/08 12:01:56 INFO mapred.JobClient:  map 100% reduce 0% 

       14/03/08 12:02:15 INFO mapred.JobClient:  map 100% reduce 100% 

       14/03/08 12:02:16 INFO mapred.JobClient: Job complete: job_201403081130_0004 

       14/03/08 12:02:16 INFO mapred.JobClient: Counters: 29 

       14/03/08 12:02:16 INFO mapred.JobClient:   Job Counters 

       14/03/08 12:02:16 INFO mapred.JobClient:     Launched reduce tasks=1 

       14/03/08 12:02:16 INFO mapred.JobClient:     SLOTS_MILLIS_MAPS=23911 

       14/03/08 12:02:16 INFO mapred.JobClient:     Total time spent by all reduces waiting after reserving slots (ms)=0 

       14/03/08 12:02:16 INFO mapred.JobClient:     Total time spent by all maps waiting after reserving slots (ms)=0 

       14/03/08 12:02:16 INFO mapred.JobClient:     Launched map tasks=2 

       14/03/08 12:02:16 INFO mapred.JobClient:     Data-local map tasks=2 

       14/03/08 12:02:16 INFO mapred.JobClient:     SLOTS_MILLIS_REDUCES=17925 

       14/03/08 12:02:16 INFO mapred.JobClient:   File Output Format Counters 

       14/03/08 12:02:16 INFO mapred.JobClient:     Bytes Written=25 

       14/03/08 12:02:16 INFO mapred.JobClient:   FileSystemCounters 

       14/03/08 12:02:16 INFO mapred.JobClient:     FILE_BYTES_READ=55 

       14/03/08 12:02:16 INFO mapred.JobClient:     HDFS_BYTES_READ=253 

       14/03/08 12:02:16 INFO mapred.JobClient:     FILE_BYTES_WRITTEN=171697 

       14/03/08 12:02:16 INFO mapred.JobClient:     HDFS_BYTES_WRITTEN=25 

       14/03/08 12:02:16 INFO mapred.JobClient:   File Input Format Counters 

       14/03/08 12:02:16 INFO mapred.JobClient:     Bytes Read=25 

       14/03/08 12:02:16 INFO mapred.JobClient:   Map-Reduce Framework 

       14/03/08 12:02:16 INFO mapred.JobClient:     Map output materialized bytes=61 

       14/03/08 12:02:16 INFO mapred.JobClient:     Map input records=2 

       14/03/08 12:02:16 INFO mapred.JobClient:     Reduce shuffle bytes=61 

       14/03/08 12:02:16 INFO mapred.JobClient:     Spilled Records=8 

       14/03/08 12:02:16 INFO mapred.JobClient:     Map output bytes=41 

       14/03/08 12:02:16 INFO mapred.JobClient:     Total committed heap usage (bytes)=415674368 

       14/03/08 12:02:16 INFO mapred.JobClient:     CPU time spent (ms)=2410 

       14/03/08 12:02:16 INFO mapred.JobClient:     Combine input records=4 

       14/03/08 12:02:16 INFO mapred.JobClient:     SPLIT_RAW_BYTES=228 

       14/03/08 12:02:16 INFO mapred.JobClient:     Reduce input records=4 

       14/03/08 12:02:16 INFO mapred.JobClient:     Reduce input groups=3 

       14/03/08 12:02:16 INFO mapred.JobClient:     Combine output records=4 

       14/03/08 12:02:16 INFO mapred.JobClient:     Physical memory (bytes) snapshot=319578112 

       14/03/08 12:02:16 INFO mapred.JobClient:     Reduce output records=3 

       14/03/08 12:02:16 INFO mapred.JobClient:     Virtual memory (bytes) snapshot=1042714624 

       14/03/08 12:02:16 INFO mapred.JobClient:     Map output records=4

      察看目的文件目录下的执行结果，看到_SUCCESS表示任务执行成功了，命令如下：

ubuntu@ubuntu-K50ID:~/hadoop-1.2.1$ bin/hadoop fs -ls ./out 

       Found 3 items 

       -rw-r--r--   1 ubuntu supergroup          0 2014-03-08 12:02 /user/ubuntu/out/_SUCCESS 

       drwxr-xr-x   - ubuntu supergroup          0 2014-03-08 12:01 /user/ubuntu/out/_logs 

       -rw-r--r--   1 ubuntu supergroup         25 2014-03-08 12:02 /user/ubuntu/out/part-r-00000

      察看执行结果part-r-00000的内容，命令如下：
      ubuntu@ubuntu-K50ID:~/hadoop-1.2.1$ bin/hadoop fs -cat ./out/part-r-00000

hadoop    1 

       hello    2 

       world    1

      至此，测试统计分析完成，hadoop启动运行正常。

4、页面访问hadoop
      通过浏览器访问jobtracker所在节点的50030端口监控jobtracker：http://192.168.1.104:50030/
      通过浏览器访问namenode所在节点的50070端口监控集群：http://192.168.1.104:50070/
      hadoop的安全机制还不完善，最好运行在内网。