Hadoop eco-system

+/Hdfs architecture:

1-HDFS Client : which responsable for submit request.

2-Name Node: Contains meta-data which are Number of blocks, their locations, on which request and other details.

*Task of Name Node:

a) Manage file system

b)Regulate client access to file

c)Execute file system execution(open and close files,open and close directories…)

3-NameNodes: Are the slaves nodes in HDFS unlike NameNode, DataNode is not an expansive system. The DataNode is block server that stores the data in the local file ext3 or ext4.

4-Secondary NameNode: Secondary NameNode in hadoop is a specially dedicated node in HDFS cluster whose main function is to take checkpoints of the file system metadata present on namenode. It is not a backup namenode. It just checkpoints namenode’s file system namespace. The Secondary NameNode is a helper to the primary NameNode but not replace for primary namenode.