编程知识 cdmana.com

1、Hadoop Several modes of operation ?

Hadoop The operation mode includes : Local mode 、 Pseudo distributed mode 、 Fully distributed mode
2、SCP Command to use

Secure copy , It can copy data between servers
3、rsync Command to use

Remote synchronization tool . Mainly used for backup and mirroring . Fast speed 、 Advantages of avoiding the same content and supporting symbolic links .
4、rsync\SCP Different

use rsync Make a copy of the file than scp Fast ,rsync Only update the difference file ,scp It's copying all the files .

5、DataNode and NameNode Processes can only work one at a time , Investigation plan .

First jps Command to check , The problem may be that the formatting is not turned off DataNode, Then close it DataNode and NameNode

then , Delete the generated data Contents and logs Catalog , Finally, execute the format command again

版权声明
本文为[Lu Zhenliang]所创,转载请带上原文链接,感谢

Scroll to Top