Cloudera Certified Administrator for Apache Hadoop CDH4 認定 CCA-410 試験問題:

1. Where does a MapReduce job store the intermediate data output from Mappers?

A) On the underlying filesystem of the local disk of the machine on which the Mapper ran.
B) On the underlying filesystem of the local disk machine on which the JobTracker ran.
C) Stores on the underlying filesystem of the local disk of the machine on which the Reducer.
D) In HDFS, in temporary directory defined mapred.tmp.dir.
E) In HDFS, in the job's output directory.

2. Under which scenario would it be most appropriate to consider using faster (e.g 10 Gigabit) Ethernet as the network fabric for your Hadoop cluster?

A) When the typical workloads consists of processor-intensive tasks.
B) When the typical workloads consumes a large amount of input data, relative to the entire capacity of HDFS.
C) When the typical workloads generates a large amount of output data, significantly larger than the amount of intermediate data.
D) When the typical workloads generates a large amount of intermediate data, on the order of the input data itself.

3. You configure Hadoop cluster with both MapReduce frameworks, MapReduce v1 (MRv1) and MapReduce v2 (MRv2/YARN). Which two MapReduce (computational) daemons do you need to configure to run on your master nodes?

A) JournalNode
B) ResourceManager
C) JobTracker
D) NodeManager
E) ApplicationMaster

4. What action occurs automatically on a cluster when a DataNode is marked as dead?

A) The NameNode forces re-replication of all the blocks which were stored on the dead DataNode.
B) The NameNode informs the client which write the blocks that are no longer available; the client then re-writes the blocks to a different DataNode.
C) The replication factor of the files which had blocks stored on the dead DataNode is temporarily reduced, until the dead DataNode is recovered and returned to the cluster.
D) The next time a client submits job that requires blocks from the dead DataNode, the JobTracker receives no heart beats from the DataNode. The JobTracker tells the NameNode that the DataNode is dead, which triggers block re-replication on the cluster.

5. Once a client application validates its identity and is granted access to file in a cluster. What is the reminder of read path back to the client?

A) the namenode maps the read request against the block locations in its stored metadata and reads those blocks from the datanodes. The client applications then read the block from the namenode
B) The namenode maps the read request against the block locations in it's stored metadata the block id's are stored by their distance to the client and moved to the datanode closest to the client according to hadoop rac topology. The client application then reads the blocks from the single datanode
C) The namenode gives the client the block ID's and a list of Datanodes on which those blocks are found. And the application reads the block directly from the datanodes

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