问题描述：在集群上，用hive分析数据出现如下错误
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. MetaException(message:Got exception: org.apache.hadoop.security.AccessControlException Permission denied: user=root, access=WRITE, inode="/data/${ip}/20180713":hdfs:supergroup:drwxr-xr-x at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.checkFsPermission(DefaultAuthorizationProvider.java:257) at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.check(DefaultAuthorizationProvider.java:238) at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.check(DefaultAuthorizationProvider.java:216) at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.checkPermission(DefaultAuthorizationProvider.java:145) at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:138) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkPermission(FSNamesystem.java:6609) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkPermission(FSNamesystem.java:6591) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkAncestorAccess(FSNamesystem.java:6543) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirsInternal(FSNamesystem.java:4333) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirsInt(FSNamesystem.java:4303) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirs(FSNamesystem.java:4276) at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.mkdirs(NameNodeRpcServer.java:867) at org.apache.hadoop.hdfs.server.namenode.AuthorizationProviderProxyClientProtocol.mkdirs(AuthorizationProviderProxyClientProtocol.java:322) at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.mkdirs(ClientNamenodeProtocolServerSideTranslatorPB.java:603) at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java) at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:617) at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:1060) at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2086) at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2082) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:422) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1707) at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2080) )
问题分析与解决：
根据报错信息是hdfs文件的权限问题，命令进入集群执行的用户为root，而hdfs文件所有者为hdfs。
要么以用户hdfs执行命令，要么调整hdfs文件的权限
解决方案1：
vim /etc/profile
增加内容
export HADOOP_USER_NAME=hdfs
解决方案2：
vim $HADOOP_HOME/etc/hadoop/hdfs-site.xml
增加内容
<property> <name>dfs.permissions.enabled</name> <value>false</value> <description> If "true", enable permission checking in HDFS. If "false", permission checking is turned off, but all other behavior is unchanged. Switching from one parameter value to the other does not change the mode, owner or group of files or directories. </description> </property>
之后重启hdfs namenode
hadoop-daemon.sh stop namenode hadoop-daemon.sh start namenode
执行完之后，namenode可能会进入安全模式一段时间，
这时候可能会报错：
name node is in safe mode
稍等一下重试一下即可。
如果，时间太长了，可以手动停止：
dfsadmin -safemode enter #进入安全模式 dfsadmin -safemode leave #离开安全模式 dfsadmin -safemode wait #等待，一直到安全模式结束