linux日志文件在哪 大数据集群常见问题总结(4)

atorg.apache.hadoop.dfs.DFSClient$DFSOutputStream.processDatanodeError(DFSClient.java:2158)at org.apache.hadoop.dfs.DFSClient$DFSOutputStream.access$1400(DFSClient.java:1735

at org.apache.hadoop.dfs.DFSClient$DFSOutputStream$DataStreamer.run(DFSClient.java:1889)

java.io.IOException: Could not get block locations. Aborting…at org.apache.hadoop.dfs.DFSClient$DFSOutputStream.processDatanodeError(DFSClient.java:2143)

at org.apache.hadoop.dfs.DFSClient$DFSOutputStream.access$1400(DFSClient.java:1735)

at org.apache.hadoop.dfs.DFSClient$DFSOutputStream$DataStreamer.run(DFSClient.java:1889)

问题原因是linux机器打开了过多的文件导致。解决方法：用命令ulimit -n可以发现linux默认的文件打开数目为1024，修改/ect/security/limit.conf，增加hadoop soft 65535，再重新运行程序（最好所有的datanode都修改），问题解决。

12. bin/hadoop jps后报如下异常：

Exception in thread "main" java.lang.NullPointerException

atsun.jvmstat.perfdata.monitor.protocol.local.LocalVmManager.activeVms(LocalVmManager.java:127)atsun.jvmstat.perfdata.monitor.protocol.local.MonitoredHostProvider.activeVms(MonitoredHostProvider.java:133)at sun.tools.jps.Jps.main(Jps.java:45)

解决方法：系统根目录/tmp文件夹被删除了。重新建立/tmp文件夹即可。

13. bin/hive中出现 unable to create log directory /tmp/

解决办法：系统根目录/tmp文件夹被删除了。linux日志文件在哪重新建立/tmp文件夹即可。

14．MySQL报错

[root@localhost mysql]# ./bin/mysqladmin -u root password ‘123456‘

./bin/mysqladmin: connect to server at ‘localhost‘ failed

error: ‘Can‘t connect to local MySQL server through socket ‘/tmp/mysql.sock‘ (2)‘

Check that mysqld is running and that the socket: ‘/tmp/mysql.sock‘ exists!

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