Secondary name node
- A secondary name node is another daemon.
- The secondary name node is not a standby name node, so it is not meant as a backup in case of name node failure.
- The primary purpose of secondary name node is to periodically download the name node fsimage and edit the log file from the name node, create a new fsimage by merging the older fsimage and edit the log file, and upload the new fsimage back to the name node.
- By periodically merging the namespace fsimage with the edit log, the secondary name node prevents the edit log from becoming too large.
Nireekshan