Hadoop-hdfs, MapReduce Learning Essays

Hdfs:

1. Distributed File System: A file system stored across multiple computers in the management network

2, Hadoop defines an abstract file system concept, specifically a Java abstract class: Org.apache.hadoop.fs.FileSystm, as long as a file system implementation of the interface, it can be used as a Hadoop supported file system

3. Data BLOCK:

The default storage in HDFs is a block of 64M, and if one file is less than 64M, it does not occupy the entire block of data

Hadoop Dfsadmin-report View basic statistics for HDFS

Feel good to explain the article link:

Http://www.cnblogs.com/sharpxiajun/archive/2013/06/15/3137765.html

Http://www.cnblogs.com/xia520pi/archive/2012/05/28/2520813.html

Mapreduce:

Http://www.cnblogs.com/sharpxiajun/p/3151395.html

Hadoop-hdfs, MapReduce Learning Essays