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

Question-: You are planning to setup new Cassandra cluster with the single token architecture and should span datacenters. It is ideal to have seed nodes from the single datacenter only?
A. True
B. False

Answer: B
Exp: No, it is not ideal. You have to make sure that the seed nodes are from each datacenter. At least one seed node from each datacenter. General requirement is that you should have 2 to 3 nodes as seed nodes per datacenter.

Dev/Admin


Question-: ___________________ refers to how up-to-date and synchronized a row of data is on all of its replicas.
A. Transaction
B. Compaction
C. Consistency
D. Compression

Answer: C

Explanation: Consistency is any distributed database is a property which refers that how up-to-date and synchronized a row of data is on all of its replicas.

Dev/Admin


Question-: Which of the following command would flush the memtable without listening for connections to other nodes?
A. nodetool drain
B. nodetool flush
C. nodetool commit
D. nodetool tpstats

Answer: A
Exp: You can manually flush the memtable using the “nodetool flush� or “nodetool drain� command. Where “nodetool drain� command flushes the memtables without listening for connections to other nodes). And if you want to reduce the overall replay time of the commit log, in case node restarts needed. Then it is recommended that flush the memtable before restarting the nodes. If a node stops working, then you should replay the commit logs which will restore the writes to the memtable that were there before the node stopped.

Related Questions

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Question-: You are facing performance issue with your Cassandra cluster, specifically you observe particular node is not performing as required and facing the issue of the load balance. Which of the following command would be helpful in this case from the nodetool utility?
A. gossipinfo
B. info
C. gcstat
D. ring
E. assassinate
And : D
Exp : “nodetool ring� provides the status and information about the ring, specially provides the idea of the load balance and if any nodes are down. Suppose your node is correctly configured it may show a different ring. Following information, you can get from the nodetool utility
- It shows the info about the tokens in the ring
- Cluster-level, table level from the perspective of the queried node.
- It can be used to determine the balance of tokens in the cluster.
- Check the load column value to determine the balance of load.
- Even if you see hotspot in your ring you can utilize detail from this command output.



Admin only
Question-: When you run the command “nodetool tablestats -H –keyspace_name� . The output generated is all the tables in the provided keyspace across entire cluster?
A. True
B. False


Question-: By using the “tablestats� command which of the following info is available to us?
A. It would tell us whether the table has been flushed to disk or not.
B. You can get the detail about the resources consumed by a table.
C. It would give the detail, about how much overall size of the database
D. It would let us know overall uptime of the Cassandra cluster.


Question-: You are working in Acmeshell Inc. where they have node cluster setup. One of the data scientists had reported that, while querying the table they see slowness since last couple of hours. Which of the following command you would be using to check this detail?
A. nodetool tablestats
B. nodetool ring
C. nodetool tablehistograms
D. nodetool gcstats
E. nodetool failuredetector


Question-: You run the following command of the nodetool

nodetool tpstats

Which generates initial output as below. What do you think or infer from this output?


A. There is an issue with the Compaction process.
B. JVM is unable to flush the memtable.
C. JVM is unable to reclaim the memory space.
D. There 674 rows which are yet to be processed.
E. There 674 columns which are yet to be processed.



Question-: Which of the following statements are true with regards to garbage collection in the Cassandra, database?
A. You should have as much as low gc as possible.
B. You should have as high as possible gc
C. gc info is just to know, how much data is being ignored. And not that critical.
D. Using the “nodetool gcstats� command you would get to know, what is the current stats of the gc since last time command was executed.


Question-: if you wanted to know that all the nodes are having the same schema info, then which of the following command you would be using?
A. nodetool ring
B. nodetool nodestats
C. nodetool failuredetect
D. nodetool gossipinfo