检查数据节点日志hadoop-hadoop-datanode.log发现有
2012-10-09 09:18:25,661 INFO org.apache.hadoop.ipc.RPC: Server at host137/192.168.6.137:9000 not available yet, Zzzzz...
2012-10-09 09:18:27,662 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: host137/192.168.6.137:9000. Already tried 0 time(s).
2012-10-09 09:18:28,663 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: host137/192.168.6.137:9000. Already tried 1 time(s).
2012-10-09 09:18:29,664 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: host137/192.168.6.137:9000. Already tried 2 time(s).
2012-10-09 09:18:30,665 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: host137/192.168.6.137:9000. Already tried 3 time(s).
2012-10-09 09:18:31,666 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: host137/192.168.6.137:9000. Already tried 4 time(s).
2012-10-09 09:18:32,667 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: host137/192.168.6.137:9000. Already tried 5 time(s).
2012-10-09 09:18:33,667 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: host137/192.168.6.137:9000. Already tried 6 time(s).
2012-10-09 09:18:34,668 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: host137/192.168.6.137:9000. Already tried 7 time(s).
2012-10-09 09:18:35,669 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: host137/192.168.6.137:9000. Already tried 8 time(s).
2012-10-09 09:18:36,670 INFO org.apache.hadoop.ipc.Client: Retrying connect to server: host137/192.168.6.137:9000. Already tried 9 time(s).
这样的信息。DataNode无法连接到NameNode造成。
之前无此问题，后检查到/etc/hosts发现有人修改了主机到ip的映射内容。