Big Data Online Practice Test - 14

Q. Below are few statements, with blanks(options in brackets),describing Hadoop features.
a) The default heartbeat interval,from datanode to namenode,is __________ seconds.(5,3)
b) In HDFS, the __________ command is used to copy,a directory present in one node,to another node.(distcp,rcp,dcp)
c) Hadoop offline image viewer command,for older versions of Hadoop is __________(oiv_legacy,oivlegacy,oiv)
Mark the correct combination of options provided from the brackets.

Q. A group of developers,were told to state,a few points, about HDFS Rack awareness policy, in their own words.
Consider the following statements.
Dev 1- Rack awareness,allows placing read/write requests,to the replica's present in the same, or,nearby rack.This leads to minimizing reading,and,writing costs.
Dev 2- The chances of a rack failure,are same as that of a node failure,in a huge Hadoop cluster.This may affect,the overall MapReduce job performance.
Dev 3- When replica's are placed in the same rack,it causes higher bandwidth use and higher latency.
Mark the correct answer.

Q. Some of the Spark framework features are mentioned below.Mark them as True / False.
1) Spark has its own file management system.
2) Cost of Spark data processing is very high,as data is kept in-memory.
3) We can reuse Spark code for batch processing.
4) The Spark job should be manually optimized.
Mark the correct answer.

Q. In a quiz,some of the features,were mentioned. Mark if the feature is of Apache Spark or Storm.
1) This framework processes events one at a time.
2) Framework provides good support,for stateful computation.
3) It guarantees that each record,will be processed at least once.
4) This framework performs data-parallel computations.
Choose the correct option.

Q. In a quiz, leads were asked to mention,the type of metastore,whose description was appropriate.
1) This metastore mode,is suitable for unit testing.
2) Many users can access, hive in this mode, even though,metastore services are running,in the same JVM.
3) This metastore mode offers,more availability, manageability and security.
Choose the correct answer

Q. A developer was told to execute,following statements in MongoDb.
1) Find all documents,where the Beaches is set to Yes,from Travelogue set.
2) Search Null values in Sanctuary column,from Travelogue set.
Mark the correct option.

Q. A fresher was told,to write a query,in Pig query language, that would display,all the capitals of world,in uppercase,from nationsworld.tsv file.
Which of the following,is a correct implementation,of the same.

Q. A developer was told to,change the name of the output filename,from part-* to "result-*".
Since he was not sure,he asked his peers,about the same.He got the following replies
Peer A - I think you should configure it in mapred-site.xml file.
Peer B - Use job.getConfiguration().set("mapreduce.output.basename", "result");
Peer C - Use Java class MultipleOutputFormat, method addNamedOutput,to change the file name.
Peer D - Use Java class OutputFormat.setOutputFormatClass,to change the file name.
Mark the correct option.

Q. A fresher was asked,to mark the correct or incorrect statements,about JPS command.
1) JPS is a part of the java distribution,and, gives information,about the java processes running in the Jvm.
2) JPS command gives information, of the Hadoop daemons and their status.
3) JPS is a part of Java distribution,since its version 1.5.
Choose the correct option.

Q. A technical writer,wrote the following points,on Cassandra tables. Mention,which one of these, are Valid or Invalid.
1) Data is written in the Memtable,after it has been written in the Commit log.
2) Memtable is a temporary location,which acts, as a,recovery crash mechanism.
3) Data in the memtable,is written to the disk, once, they are full,to form SSTables.
4) Data is written in the memtable,during updation or deletion.
Mark the correct option.