CASSANDRA Architecture and Data Model 3

Question 1

In Cassandra, what is the 'coordinator node'?

Accepted Answer

The node that receives a client request and routes it to the correct replicas

Answer

The dedicated master node

Answer

The node that holds the schema definition

Answer

The node that performs compaction

Question 2

What is 'read repair' in Apache Cassandra?

Accepted Answer

Synchronizing divergent replicas by comparing and updating them during a read

Answer

Rebuilding corrupt SSTables

Answer

Rewriting outdated partition keys

Answer

Compacting SSTables after a read-heavy period

Question 3

What does the 'NetworkTopologyStrategy' replication strategy allow you to configure?

Accepted Answer

Different replication factors per data center

Answer

Per-table replication factors

Answer

Node rack assignment

Answer

Token range assignment per vnode

Question 4

Which file in a Cassandra SSTable set stores the partition index for fast lookups?

Accepted Answer

Index.db

Answer

Data.db

Answer

Filter.db

Answer

Summary.db

Question 5

What is the purpose of 'gc_grace_seconds' in Cassandra?

Accepted Answer

The period tombstones must persist before being eligible for deletion during compaction

Answer

The time before a node is evicted from the ring

Answer

The grace period for schema change propagation

Answer

The delay before a MemTable flush

Question 6

What mechanism does Cassandra use to detect and recover from failed nodes automatically?

Accepted Answer

Gossip protocol with hinted handoff

Answer

Paxos consensus

Answer

ZooKeeper coordination

Answer

Raft leader election