Which two are features of Hadoop’s rack topology?
A.
Even for small clusters on a single rack, configuring rack awareness will improve
performance
B.
Configuration of rack awareness is accomplished using a configuration file. You cannot
use a rack topology script.
C.
Hadoop gives preference to intra-rack data transfer in order to conserve bandwidth
D.
Rack location is considered in the HDFS block placement policy
E.
HDFS is rack aware but MapReduce daemon are not
B,D
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C & D are the correct answers.
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C,D
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C,D
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https://hadoop.apache.org/docs/r2.7.2/hadoop-project-dist/hadoop-common/RackAwareness.html
Correct:
C. Intra-rack because network bandwidth between machines in the same rack is greater than
network bandwidth between machines in different racks
D. HDFS block placement Configuration of rack awareness is accomplished using a configuration filewill use rack awareness for fault tolerance by placing one block replica on a different rack
Incorrect:
B. You can use a rack topology script.
E. Also MapReduce is rack awareness, example: mapreduce.jobtracker.taskcache.levels
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C,D
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