DataStax Cassandra Developer Certification Certification Questions and Answer (Dumps and Practice Questions)

Question : Select all correct statements which applies to seed nodes
A. Use the multiple list of seed nodes in a cluster, so all nodes quickly learn about all other nodes in the cluster
B. The seed node designation has no purpose other than bootstrapping the gossip process for new nodes joining the cluster
C. Seed nodes are not a single point of failure
D. Seed nodes are a single point of failure


1. A,B
2. B,C
3. C,D
4. A,D
5. B,D

Correct Answer : 2
Explanation: To prevent problems in gossip communications, use the same list of seed
nodes for all nodes in a cluster. This is most critical the first time a node starts up.
By default, a node remembers other nodes it has gossiped with between subsequent restarts.
The seed node designation has no purpose other than bootstrapping the gossip process
for new nodes joining the cluster. Seed nodes are not a single point of failure, nor do they have any other
special purpose in cluster operations beyond the bootstrapping of nodes.





Question : Select all correct statements which applies to seed nodes
A. In multiple data-center clusters, the seed list should include at least one node from each data center (replication group).
B. More than a single seed node per data center is recommended for fault tolerance
C. Making every node a seed node is recommended for fault tolerance
D. It is recommended to use a small seed list (approximately three nodes per data center).


1. A,B,C
2. B,C,D
3. A,C,D
4. A,B,D

Correct Answer : 4
Explanation: In multiple data-center clusters, the seed list should include at least one node
from each data center (replication group).
More than a single seed node per data center is recommended for fault tolerance. Otherwise, gossip has to
communicate with another data center when bootstrapping a node.
Making every node a seed node is not recommended because of increased maintenance and reduced gossip performance.
Gossip optimization is not critical,
but it is recommended to use a small seed list (approximately three nodes per data center).





Question : In Cassandra database, which of the following help us to put new row on a particular node in a cluster.



1. Hashing

2. Partitioner

3. Gossip protocol

4. Grouping

5. Timestamps


Correct Answer : 2
Explanation: A partitioner determines how data is distributed across the nodes in the cluster (including
replicas).
Basically, a partitioner is a function for deriving a token representing a row from its partition key,
typically by hashing. Each row of data is then distributed across the
cluster by the value of the token.

Related Questions

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Question : You can also specify specific IP addresses of Cassandra cluster nodes, so that you will hit to only specific node
in cluster, initially

1. True
2. False


Question : As soon as you create Cluster instance, you are connected to Cassandra cluster

1. True
2. False


Question : . You should always prefer to use SSD storage on Cassandra node?

1. True
2. False


Question : You can use network attached storage and needs to be avoided for Cassandra node ?

1. True
2. False


Question : Which of the following statements are correct?

A. You can write data on any node in Cassandra cluster
B. Any node in the cluster can work as Coordinator
C. You have to define 1/4 th of total node as Cassandra Cluster
D. Coordinator is optional in Cassandra


1. A,B
2. B,C
3. C,D
4. A,D
5. B,D


Question : Using driver you can connect to specific node, for which your data belongs to and you can do read and write only
on that node in Cassandra ring

1. True
2. False