hadoop-2.x --new features

  as of hadoop-2.5.1,there  are some important features of hadoop 2.x for me to learn these days

 

new key features	abstract
NN HA (high availability)	standby meta node,failure over anytime,maybe same as  hbase-backup master
HDFS Federation	union all nameapes from different rights
HDFS snapshot
short circuit reads
exeuction framework YARN	run any type apps what you want on it,eg. MR,DAG...
RM HA	same as above

 

  of  course,relate to hadoop 1.x,increasing learnings are important,as this will save you lot of time to study from scatch,you only need to focus the key features or new components what you want to see only!

 

ref:

useful official docs about hadoop architecture

 Hadoop0.23.0初探1

Hadoop0.23.0初探2

Hadoop 0.23.x/NameNode federation原理、编译、安装、体验