CASSANDRA Professional Development 3 — Questions and Answers
Question 1: A Cassandra professional is asked to estimate cluster sizing for a new project. Which factor is most important to establish first?
- Number of developers on the team
- Expected read/write throughput and data volume (Correct answer)
- Preferred programming language
- Budget for licensing fees
Correct answer: Expected read/write throughput and data volume
Throughput requirements and data volume directly determine the number of nodes, replication factor, and hardware specs needed.
Question 2: Which hands-on practice activity best prepares someone for a Cassandra production role?
- Building a multi-node cluster, simulating node failures, and observing repair behavior (Correct answer)
- Reading whitepapers without running any queries
- Practicing SQL joins on PostgreSQL
- Configuring Oracle RAC for high availability
Correct answer: Building a multi-node cluster, simulating node failures, and observing repair behavior
Simulating failures and running repairs on a real cluster builds the operational intuition needed for production incidents.
Question 3: When writing a resume for a Cassandra DBA position, which metric best demonstrates operational competence?
- Number of tables created
- Cluster size managed, uptime maintained, and throughput handled (Correct answer)
- Number of SELECT queries written
- Lines of CQL code produced
Correct answer: Cluster size managed, uptime maintained, and throughput handled
Employers look for scale indicators like nodes managed, SLA uptime, and data throughput to gauge operational experience.
Question 4: Which Cassandra-specific skill is most valued when joining a team that already has a large production cluster?
- Ability to rewrite the cluster from scratch
- Diagnosing performance issues using nodetool and system tables (Correct answer)
- Migrating the cluster to MySQL
- Adding foreign key constraints to existing tables
Correct answer: Diagnosing performance issues using nodetool and system tables
On an existing cluster, the immediate value-add is operational diagnostics using nodetool stats, tpstats, and system tables.
Question 5: What does the DataStax Academy free online training primarily offer for Cassandra learners?
- Live instructor-led sessions only, no self-paced content
- Self-paced courses on Cassandra fundamentals, data modeling, and administration (Correct answer)
- Exclusively exam prep for AWS certifications
- Only advanced research papers with no labs
Correct answer: Self-paced courses on Cassandra fundamentals, data modeling, and administration
DataStax Academy provides free self-paced courses covering CQL, data modeling, drivers, and cluster administration.
Question 6: A Cassandra engineer is asked to mentor a junior developer. Which topic should be taught first?
- Advanced compaction strategy tuning
- The CAP theorem and how Cassandra's consistency levels map to it (Correct answer)
- Writing Cassandra drivers from scratch
- Configuring JVM garbage collection for G1GC
Correct answer: The CAP theorem and how Cassandra's consistency levels map to it
Understanding the CAP theorem and consistency levels gives juniors the conceptual foundation for all Cassandra decisions.
Question 7: Which career path is a natural progression for a senior Cassandra DBA with strong distributed systems knowledge?
- Transitioning to mainframe COBOL development
- Becoming a distributed systems architect or site reliability engineer (Correct answer)
- Moving to spreadsheet-based data management
- Specializing in single-node SQLite deployments
Correct answer: Becoming a distributed systems architect or site reliability engineer
Deep expertise in distributed databases like Cassandra translates directly into distributed systems architecture and SRE roles.
CASSANDRA Professional Development 3
A Cassandra professional is asked to estimate cluster sizing for a new project.
Which factor is most important to establish first?