Datastax Cassandra Administrator Certification Questions and Answer (Pratice Questions and Dumps)

Question-: In which of the following situation you would be using DSBulk tool?
A. If we have a lot of files which needs to be loaded in different tables then we should use DSBulk tool.
B. If you wanted to take the backup of data from the Cassandra cluster then we should use this tool.
C. If data model changes for our existing data and we wanted to move it to the new data model then you should use this tool.
D. While migrating data from one Cassandra database to another Cassandra database.
E. While converting JSON data to csv data.


Answer: A, B, C, D
Exp: DSBulk tool can be used for loading huge volume of data to Cassandra database. And it supports gigabytes of data load/unload. So, this is one of the convenient tools for loading bigger volume of data. Even if you are using multiple files which needs to be loaded into many tables in the same Cassandra database then you should use this tool. If you wanted to take the backup of your present Cassandra database then just download the data or export the data using this tool and create a backup file.

At the later stage if you have found that your data model is not efficient and you need to change this data model so what you can do you download your existing data from the existing cluster and Same data can be uploaded into the new data model using the DSBulk tool.



Question-: To get the backup of the data you run the snapshot command; it would create a snapshot for the data which are in the as SSTable as well as in the memtable?
A. True
B. False

Answer: B
Exp: When you are going to take the snapshot of the existing data in the database. It will create the snapshot from the SSTable files only and does not consider the data which is in the Memtable. So if you want to take the backup of the current data in the memtable as well then you should first flush the data to SSTable, then take the snapshot.



Question-: When you take up Snapshot for one of the SSTable on a particular node then it would not take a backup of the entire cluster?
A. True
B. False

Answer: A
Exp: When you take a backup using the snapshot then it would create a snapshot of SSTable only for the data which exist on that node. It would not consider the data which are residing on any other node in the cluster, even for the same table.

Related Questions

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Question-: In Cassandra cluster you should initiate the repair command for?
A. Adding or removing new nodes to the cluster.
B. if node goes out of the cluster then using repair command you can bring it back in the cluster.
C. using the repair command you can synchronize all the replicas in the Cassandra cluster.
D. using repair command client can reconnect with the Cassandra cluster if connection is broken.


Question-: You have set up a Cassandra cluster with nodes, three nodes in each datacenter. It was found that because of network disconnect for almost minutes one of the data center got disconnected. And you are worried that there were lot of write happening on the database during that time. What would you do in this case when network connectivity re-established?

A. You would execute it nodetool synchronize command.
B. you would execute nodetool repair command.
C. you would execute nodetool rejoin command
D. you would execute nodetool reconnect command


Question-: In Cassandra cluster to repair dropped writes, which of the following data structure is used to compare the data between two nodes?
A. B- tree
B. Merkel tree
C. Hashtable
D. Log data structure


Question-: You are trying to repair a table using nodetool repair command, but you have found that repair is not executed on that table. What could be the possible reason?
A. Because NodeSync is already enabled on the table
B. Repairing disable on that table
C. The node which is hosting the table is down.
D. This table was already repaired 6 hours before.


Question-: Which of the following is/are correct for repairing table on a particular node?
A. You should run when node was disconnected from the cluster for some time.
B. You should run repair command at least once before gc_grace_second expire
C. You have to make sure that your repair can finish before gc_grace_second window expire
D. You should run repair command when node is under high utilization.



Question-: Please map the following options for the Nodetool repair command.

A. - -par
B. - -pr
C. - - st
D. - - local

1. Parallel repair
2. Repairs only the primary token range
3. Access Mostly Uused Products by 50000+ Subscribers
4. Apply repairs only in the local datacenter.