Question-161: Which of the tool you can use to monitor, bootstrap, replace, move/remove progress of the node?

Answer: As discussed previously you can use “nodetool netstats” command. This will show the progress of the streaming operation.

Question-162: If you found that during the Bootstrap, node movement and node replace causing the range movements of the tokens. then how can you solve this?

Answer: For this you have to run “nodetool cleanup” commands on the node which has lost range to the joining node, and this should be done only when you are satisfied the new node is up and working. If you don't do this then old data will still be counted against the load on that node.  

Question-163: If node down, and you suspect that some writes have been missed. How can you to solve this issue?

Answer: The coordinator node maintains the hints, when it found any node is down and data has to be written on that particular node. If node comes back later it can replay those hints on that node. however, it does not guarantee that hundred percent write which were missed would be written.

Questions-164: What all types of repairs you can apply on Cassandra?

Answer: there are two types of repairs

• full repair
• incremental repair

In case of full repair, it works on the entire range off the data in the token range that is being repaired. Instead incremental repairs only repair data that is been written since the previous incremental repair. 

Question-165: Can you tell me something more about incremental repair?

Answer: Incremental repair is the defaults one and that runs regularly. If incremental repair marks the data as repaired, it would not try to repair again. 

This is fine for syncing up missed writes, but it does not protect against like disk corruption, Data loss by operator error. Hence, full repair should be Run occasionally.