Apache HDFS Architecture and Components HDFS means Hadoop Distributed File System and it manages big data sets with high volume. HDFS stores the data at distributed manner and it is the primary storage system. HDFS allows read and write the files but cannot updated the files in HDFS. When we move file in HDFS that file are splited into small files. HDFS are implemented by Master Slave architecture. Main Components of HDFS: 1. NameNode 2. Secondary NameNode 3. DataNode 4. Block NameNode: NameNode is the heart and master oh Hadoop It maintains the namespace system of hadoop NameNode stores the metadata of data blocks that data are permanently stored on Local disk It reduced disk space also. Secondary NameNode: Main role of secondary namenode is copy and merge the namespace. Secondary namenode requires huge amount of memory to merge the files. If namenode failure namespace images are stored in secondary namenode and it can be restart the namenode. Data