hadoop配置出错信息汇总

1：INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:12200. Already tried 0 time(s).

运行
ximo@ubuntu:~$ hadoop fs -ls

14/01/08 22:01:41 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:12200. Already tried 0 time(s).
14/01/08 22:01:42 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:12200. Already tried 1 time(s).
14/01/08 22:01:43 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:12200. Already tried 2 time(s).
14/01/08 22:01:44 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:12200. Already tried 3 time(s).
14/01/08 22:01:45 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:12200. Already tried 4 time(s).
14/01/08 22:01:46 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:12200. Already tried 5 time(s).
14/01/08 22:01:47 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:12200. Already tried 6 time(s).
14/01/08 22:01:48 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:12200. Already tried 7 time(s).
14/01/08 22:01:49 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:12200. Already tried 8 time(s).
14/01/08 22:01:50 INFO ipc.Client: Retrying connect to server: localhost/127.0.0.1:12200. Already tried 9 time(s).
mkdir: Call From Lenovo-G460-LYH/127.0.0.1 to localhost:12200 failed on connection exception: java.net.ConnectException: 拒绝连接; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused

有几种原因：

1）hadoop配置
主要是$HADOOP_HOME/conf/hdfs-site.xml、mapred-site.xml、core-site.xml中的配置是否正确，伪分布式模式可以参考前面的blog，或是网上的文章，一大堆一大堆的。
2）机器连不通
如果是分布式的，还要看hadoop客户端机器能不能ping通hdfs机器，注意hdfs的端口号
3）namenode没有启动（本人是这种原因）
$stop-all.sh 如果出现no namenode stop则表示是namenode的问题
$hadoop namenode -format
$start-all.sh
4）其他。

2：hadoop datanode无法启动 (一般是由于两次或两次以上的格式化NameNode造成)

＄jps

10309 JobTracker
10430 TaskTracker
11707 Jps
10232 SecondaryNameNode
9966 NameNode

没有dataNode服务

解决方法：

1)删除DataNode的所有资料

（将集群中每个datanode的/hdfs/data/current中的VERSION删掉hdfs为hadoop-src/conf/hdfs-site.xml中name为dfs.data.dir所指向的值/usr/local/hadoop/data/hadoop/data,所以我的/hdfs/data/current/VERSION=/usr/local/hadoop/data/hadoop/data/current/VERSION)

2)$./stop-all.sh

3）＄./hadoop namenode -format

4)$./start-all.sh

5)$jps

12680 NameNode
12807 DataNode
12941 SecondaryNameNode
13158 TaskTracker
13022 JobTracker
14119 Jps

dataNode服务重新启动

持续更新。。。。。。