hdfs 中写入文件报错
Permission denied: user=yuanjunhua, access=WRITE,
inode="/":root:supergroup:drwxr-xr-x at
org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkFsPermission(
FSPermissionChecker.java:265) at
org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPermission
Checker.java:251) at
org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPermission
Checker.java:232) at
org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FS
PermissionChecker.java:176) at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkPermission(FSNamesys
tem.java:5523) at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkPermission(FSNamesys
tem.java:5505) at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkAncestorAccess(FSNam
esystem.java:5479) at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.startFileInternal(FSNames
ystem.java:2284) at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.startFileInt(FSNamesystem
.java:2237) at
org.apache.hadoop.hdfs.server.namenode.FSNamesystem.startFile(FSNamesystem.ja
va:2190) at
org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.create(NameNodeRpcSe
rver.java:520) at
org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorP
B.create(ClientNamenodeProtocolServerSideTranslatorPB.java:354) at
org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientName
nodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java) at
org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(Protob
ufRpcEngine.java:585) at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:928)
at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2013) at
java.security.AccessController.doPrivileged(Native Method) at
javax.security.auth.Subject.doAs(Subject.java:422) at
org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.jav
a:1556) at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2007)
问题：hdfs 写入权限不够，被拒
解决方法：在hadoop中的 hdfs.xml 添加就ok
<property>
<name>dfs.permissions</name>
<value>false</value>
</property>jetty run + redis + CentOS7 的web-jps的页面操作
redis拒绝连接
Eclipase 错误显示：
redis.clients.jedis.exceptions.JedisConnectionException:
java.net.ConnectException: Connection refused: connect
在CentOS7上的错误显示：
Could not connect to Redis at 127.0.0.1:6379: Connection refused
解决方法：
在centos7上启动redis服务，此时会出现Connection refused，随后执行命令 redis-server /etc/redis.conf。也许这样还不算完，因为此时系统 会告诉你，没有这条命令。我是遇到了，怎么处理呢？此时就需要你把redis.conf 中的代码daemonize no 改成daemonize yes 并把该文件拷贝一份到目录/etc/ 下，然后再次执行命令 redis-server /etc/redis.conf——>redis-cli 则ok！