1：Hadoop 启动节点Datanode失败解决

查看日志文件 [root@hadoop current]#  vim /usr/local/hadoop1.1/logs/hadoop-root-datanode-hadoop.log STARTUP_MSG:  version = 1.1.2 STARTUP_MSG:  build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.1 -r 1440782; compiled by 'hortonfo' on Thu Jan 31 02:03:24 UTC 2013 ************************************************************/ 2014-10-31 19:24:28,543 INFO org.apache.hadoop.metrics2.impl.MetricsConfig: loaded properties from hadoop-metrics2.properties 2014-10-31 19:24:28,565 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source MetricsSystem,sub=Stats registered. 2014-10-31 19:24:28,566 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Scheduled snapshot period at 10 second(s). 2014-10-31 19:24:28,566 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: DataNode metrics system started 2014-10-31 19:24:28,728 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source ugi registered. 2014-10-31 19:24:29,221 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException:  Incompatible namespaceIDs in /usr/local/hadoop/tmp/dfs/data:  namenode namespaceID = 942590743; datanode namespaceID = 463031076 （2）进入datanode的 dfs.data.dir 的 current目录，修改里面的文件VERSION 由于我是默认的，所以路径是/usr/local/hadoop/tmp/dfs/data/current/VERSION。 这个版本不同，可能路径也不同，最好自己去找找。 [root@hadoop current]#  vim /usr/local/hadoop/tmp/dfs/data/current/VERSION ..................................................................................................................................... #Thu Oct 30 04:52:01 PDT 2014 namespaceID=463031076 storageID=DS-1787154912-192.168.0.100-50010-1413940826285 cTime=0 storageType=DATA_NODE layoutVersion=-32 改掉clusterID=namenode namespaceID = 942590743; 2：HIVE报错： FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. MetaException(message:For direct MetaStore DB connections, we don't support retries at the client level.)

这是由于字符集的问题，需要配置MySQL的字符集：

mysql> alter database hive character set latin1；

mysql和hive的关联除了要在hivelib下安装mysqlconnted外还需要在 hive-site.xml中把

<value>jdbc:mysql://localhost:3306/hive?createDatabaseIfNotExist=true</value

问题：

create table years (year string, event string) row format delimited fields terminated by '\t'; FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. MetaException(message:For direct MetaStore DB connections, we don't support retries at the client level.)

解决：

1，在hdfs中添加权限：

hadoop dfs -chmod -R 777 /tmp hadoop dfs -chmod -R 777 /user/hive/warehouse

2,在mysql中手动创建hive数据库

create hive ；

修改编码：

mysql> alter database hive character set latin1; Query OK, 1 row affected (0.00 sec) mysql> exit