Interview Questions and Answers

Apache Cassandra is a highly scalable and distributed NoSQL database system designed to handle large amounts of data across multiple commodity servers without a single point of failure.

A key space in Cassandra is a namespace that defines data replication on nodes. It is the outermost container for data, similar to a database in the relational database world.

A node in Cassandra is an individual server that stores data. Nodes work together to form a distributed and decentralized database system.

In Cassandra, a column family is a container for rows. It is similar to a table in a relational database and consists of columns and rows.

A Cassandra data center is a logical grouping of nodes that are geographically close to each other. Data centers are used for replication and fault tolerance purposes.

Cassandra achieves fault tolerance through data replication. Each piece of data is replicated across multiple nodes in the cluster, ensuring that if a node fails, the data is still available on other nodes.

Nodetool is a command-line utility in Cassandra that provides various administrative tasks, such as monitoring the cluster, managing compaction, and performing other maintenance operations.

CQL is a query language for interacting with Cassandra databases. It is similar to SQL but is specifically designed for NoSQL databases and includes support for creating, updating, and querying data in Cassandra.