什么是hadoop namenode格式？ [英] What exactly is hadoop namenode formatting?

问题描述

namenode格式化涉及到什么。如果我在我的hadoop安装文件夹中输入以下命令到我的终端：

$ $ $ $ $ bin $ hadoop namenode -format

完成的是什么？我期待了解namenode格式化的原理。其意义。谢谢...

解决方案

Hadoop NameNode是一个HDFS文件系统的集中的地方，它保持所有文件的目录树在文件系统，并跟踪整个群集中文件数据的保存位置。总之，它保持与datanodes相关的元数据。当我们格式化namenode时，它会格式化与数据节点相关的元数据。通过这样做，datanode上的所有信息都将丢失，并且可以重新用于新数据。

What exactly is involved in namenode formatting. If I type in the following command into my terminal within my hadoop installation folder:

  bin/hadoop namenode -format

What exactly does it accomplish? I am looking to understand principles of namenode formatting & its significance. Thanks...

解决方案

Hadoop NameNode is the centralized place of an HDFS file system which keeps the directory tree of all files in the file system, and tracks where across the cluster the file data is kept. In short, it keeps the metadata related to datanodes. When we format namenode it formats the meta-data related to data-nodes. By doing that, all the information on the datanodes are lost and they can be reused for new data.

这篇关于什么是hadoop namenode格式？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！