Daily Archives: April 9, 2014

Backup Node in Hadoop 4

Backup Node: Backup Node in hadoop is an extended checkpoint node that performs checkpointing and also supports online streaming of file system edits. The advantage over the checkpoint node is that the namespace (meta-data) present in it’s main memory is always in sync with primary namenode file system namespace, Since it maintains an in-memory, up-to-date copy of file system namespace and accepts a real time online stream of file system […]

Checkpoint Node in hadoop 2

Checkpoint Node Checkpoint node in hadoop is a new implementation of the Secondary NameNode to solve the drawbacks of Secondary NameNode. Main function of the Checkpoint Node in hadoop is to create periodic checkpoints of file system metadata by merging edits file with fsimage file. Usually the new fsimage¬†from merge operation is called as a checkpoint. Checkpoint Node periodically downloads the fsimage and edits log files from primary NameNode and […]