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

Question : You are working in an Investment Bank, and they have subscribed data feeds from BloomBerg, which delivers
data in various different format e.g. CSV file, Direst database access either RDBMS or NOSQL(Cassandra)
and daily incremental data. Which of the following you can use in Cassandra to load data or migrate data from one
Cassandra cluster to another.
A. CQL INSERT command
B. CQL COPY command
C. Loading CSV file directly.
D. sstableloader


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

Correct Answer : 4
Explanation: Data is inserted using the CQL INSERT command, the CQL COPY command and CSV files, or
sstableloader. But in reality, you need to consider how your client application will query
the tables, and do data modeling first. The paradigm shift between relational and NoSQL means that a straight
move of data from an RDBMS database to Cassandra will be doomed to failure.





Question : A file to which Cassandra appends changed data for recovery in the event of a hardware failure is called.


1. commit log

2. memtable

3. SSTable

4. redo log


Correct Answer : 1
Explanation: A sequentially written commit log on each node captures write activity to ensure data durability.




Question : Cassandra addresses the problem of failures by employing



1. Master-slave Architecture

2. peer-to-peer gossip communication protocol

3. peer-to-peer TCP communication protocol

4. peer-to-peer UDP communication protocol


Correct Answer : 2
Explanation: Cassandra is designed to handle big data workloads across multiple nodes with no
single point of failure. Its architecture is based on the understanding
that system and hardware failures can and do occur. Cassandra addresses the problem of failures by employing
a peer-to-peer distributed system across
homogeneous nodes where data is distributed among all nodes in the cluster. Each node frequently exchanges state
information about itself and other nodes
across the cluster using peer-to-peer gossip communication protocol.

Related Questions

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Question : Please map the bwlow.
A. Murmur3Partitioner
B. RandomPartitioner
C. ByteOrderedPartitioner

1. Provides fast hashing and good performance
2. Uniformly distributes data across the cluster based on MD5 hash values
3. Partitioner for ordered partitioning


1. A-3 B-2 C-1

2. A-2 B-1 C-3
3. A-1 B-3 C-2
4. A-1 B-2 C-3


Question : Both RandomPartitioner and MurmurPartitioner uses a cryptographic hash to generates the token hash values



1. True
2. False


Question : You are designing Cassandra cluster, and you have been asked to span cluster in Geneva,
Nevada and Hyderabad. Which of the following replication strategies you will use for this.


1. SimpleStrategy

2. NetworkTopologyStrategy

3. Murmur3Strategy

4. RandomStrategy



Question : You are designing Cassandra cluster, and you have been asked to span cluster in Geneva, Nevada and Hyderabad.
You can configure consistency level of LOCAL_QUORUM or ONE.
The two primary considerations are
(1) being able to satisfy reads locally, without incurring cross data-center latency, and
(2) failure scenarios :
Which is the best strategy to configure replications.

1. Two replicas in each data center e.g. 2 copy in each DC Geneva, Nevada and Hyderabad
2. Three replicas in each data center e.g. 2 copy in each DC Geneva, Nevada and Hyderabad
3. One replica in each data center e.g. 1 copy in each DC Geneva, Nevada and Hyderabad
4. You can have three replicas in one data center e.g. Geneva and single replica in either Nevada and
Hyderabad


Question : Replication strategy is set during



1. Keyspace creation

2. Cluster creation

3. Table Creation

4. ColumnFamily Creation



Question : Which of the following components of Cassandra help you to determine which data centers and racks nodes belong
to.


1. Network topology

2. Replication Strategy

3. Snitch

4. Partitioner