ccah-500 question 46th which scenario'll go undetected

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46.You is running Hadoop cluster with all monitoring facilities properly configured.

Which scenario would go undetected?

A. HDFS is almost full

B. The NameNode goes down

C. A DataNode is disconnected from the cluster

D. Map or reduce tasks that is stuck in an infinite loop

E. MapReduce jobs is causing excessive memory swaps

ANSWER:B-D

Reference

http://www.aiotestking.com/cloudera/which-scenario-will-go-undeselected/

B Zookeeper monitors NameNode.

http://stackoverflow.com/questions/15642688/ what-happens-when-name-node-fails-which-process-will-monitor-name-node-heart-be

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