CCA-500 無料問題集「Cloudera Certified Administrator for Apache Hadoop (CCAH)」

（A）nn01 is fenced, and nn02 becomes the active NameNode

（B）nn01 becomes the standby NameNode and nn02 becomes the active NameNode

（C）nn02 becomes the standby NameNode and nn01 becomes the active NameNode

（D）nn02 is fenced, and nn01 becomes the active NameNode

（A）Set vm.swapfile file on the node

（B）Delete the /etc/swap file on the node

（C）Set the ram.swap parameter to 0 in core-site.xml

（D）Delete the /dev/vmswap file on the node

（E）Delete the /swapfile file on the node

（A）Root access to the cluster for users hdfs and mapred but non-root access for clients

（B）User authentication on all remote procedure calls (RPCs)

（C）Authentication for user access to the cluster against a central server

（D）Encryption for data during transfer between the Mappers and Reducers

（E）Encryption for data on disk ("at rest")

（A）In YARN, the ApplicationMaster is responsible for requesting the resource required for a
specific launch. Thus, executing -D yarn.applicationmaster.reduce.tasks=2 will specify that the
ApplicationMaster launch two task contains on the worker nodes.

（B）Developers specify reduce tasks in the exact same way for both MapReduce version 1 (MRv1)
and MapReduce version 2 (MRv2) on YARN. Thus, executing -D mapreduce.job.reduces-2 will
specify reduce tasks.

（C）In YARN, resource allocation is function of virtual cores specified by the ApplicationManager
making requests to the NodeManager where a reduce task is handeled by a single container (and
thus a single virtual core). Thus, the developer needs to specify the number of virtual cores to the
NodeManager by executing -p yarn.nodemanager.cpu-vcores=2

（D）In YARN, resource allocations is a function of megabytes of memory in multiples of 1024mb.
Thus, they should specify the amount of memory resource they need by executing -D mapreducereduces.
memory-mb-2048

（E）MapReduce version 2 (MRv2) on YARN abstracts resource allocation away from the idea of "tasks" into memory and
virtual cores, thus eliminating the need for a developer to specify the number of reduce tasks, and indeed preventing
the developer from specifying the number of
reduce tasks.

（A）Hadoop fs -getemerge westUsers westUsers.txt

（B）Hadoop fs -get westUsers westUsers.txt

（C）Hadoop fs -getmerge -R westUsers.txt

（D）Hadoop fs -cp westUsers/* westUsers.txt

（A）Install the impalad daemon and the impala shell on your gateway machine, and the statestored daemon and
catalogd daemon on one of the nodes in the cluster

（B）Install the impalad daemon, statestored daemon, and catalogd daemon on each machine in the cluster and on the
gateway node

（C）Install the impalad daemon statestored daemon, and daemon on each machine in the cluster, and the impala shell
on your gateway machine

（D）Install the impalad daemon on each machine in the cluster, the statestored daemon and catalogd daemon on one
machine in the cluster, and the impala shell on your gateway machine

（E）Install the impalad daemon, the statestored daemon, the catalogd daemon, and the impala shell on your gateway
machine