Big Data Administrator Interview Questions and Answers

To troubleshoot hive slowness, check for resource contention, optimize queries, and monitor system performance.

• Check for resource contention such as CPU, memory, and disk usage

• Optimize queries by reducing data scanned and avoiding unnecessary joins

• Monitor system performance using tools like Ganglia or Ambari

• Consider partitioning tables to improve query performance

• Use compression to reduce disk I/O and network traffic

ZK and JN play a crucial role in ensuring high availability of Namenode in Hadoop cluster.

• ZK (Zookeeper) is used for leader election and maintaining the state of active and standby Namenodes.

• JN (JournalNode) is responsible for storing the edit logs of Namenode, which are used for recovery in case of failover.

• In case of Namenode failure, ZK helps in electing a new active Namenode from the standby Namenodes, while JN provides the necessary edit logs for recovery.

• Without ZK and ...read more