Here is the list of Top 35 Hadoop interview questions and answers to clear the Hadoop interview
and know about the Hadoop language.
1. What is mesnt by Hadoop?
          Hadoop is a open-sourcr platform that allows to store and it is used to manage the large
amouunt of data in the software environment.
2. What are the advantages of Hadoop?
          1. It is flexible to work
          2. Cost is less
          3. Hadoop is a fastest language
           4. Hadoop is a scalable language
           5. It is flexible to future
3. What are the disadvantages of Hadoop?
          1. security complex
          2. It is not suitable for the small amout of data
          3. For nature it is endangered
          4. general Limitations
          5. potential stability issues
4.    What are the fields comes under the umbrella of big data?
           1. Block box data
           2. Social media data
           3. Stock exchange data
           4. Power grid data
           5. Transport data
           6. Search engine data
5. What are the types of data involved in the big data?
           1. Structured data
           2. Semi structure data
           3. Unstructured data
6. What are the challenges of the Big data?
           1.Data capturing
           2. Data curation
           3. Storage of data
           4. Data searching
           5. Data sharing
           6. Data transferring
           7. Analysis of data
           8. Presentations
7. What are two classes of technology involved in Big data?
        1. Operational big data
        2. Analytical big data
8. What is technology used in used in operational big data?
          In Operational data, NoSQL technology is used.
9. In Analytical big data the queries are selective or unselective?
            It is used unselective queries.
10. How many modules are involved in the hadoop architecture and what are they?
         1. Hadoop common
         2. Hadoop YARN
         3. HDFS
         4. Hadoop Mapreduce
11. Is it hadoop mapreduce is YARN based or not?
            Yes. it is YARN based.
12. What is the job of the hadoop YARN?
             The role of the hadoop YARN is arranging the job scheduling and manage the
bunch of resource.
13. Waht is meant by Mapreduce in hadoop?
            It is a software structure in used to writing applications which is process large amounts
of data in a parallel manner.
14. What is the full form of the HDFS?
             Hadoop Distributed File system is the full form of HDFS
15. Mention the types of nodes available in the HDFS?
          There are types of nodes present.They are
                  1. Namenode
                  2. Data node
16. Whether the HDFS is based on the GFS or not?
            Yes. HDFS is based on the GFS(Google File System)
17. What are the types of operations modes are available in the hadoop?
            There are three types of modes are present
                 1. Local/standalone mode
                 2. Pesudo distributed mode
                 3. Fully distributed mode
18. What are the goals of the HDFS?
              1. It is used to detect the fault and recover that
              2.  It is managing the huge amonut of data sets
              3. Data hardware
19. What are the features of the HDFS?
              1. It is adoptable for spreading the storage and processing
              2. HDFC interact with the help of hadoop commands
              3.  It is used for parallel processing of data
20. What command is used to shutting down the HDFS?
           $ stop-dfs.sh
21. Mentions any four objects inside the HDFS?
         ls <path>
         lsr <path>
         du <path>
        dus <path>
22. What is the command to kill the job?
         $ $HADOOP_HOME/bin/hadoop job -kill<JOB-ID>
23. What is the command used to see the history of the job output?
        $ $HADOOP_HOME/bin/hadoop job -history <DIR-NAME>
24. Give the syntax to see the job status in hadoop?
         $ $HADOOP_HOME/bin/hadoop job -status <JOB-ID>
25. Mention any four generic options available in a hadoop job?
       1. submit<job-file>
       2. status <job-id>
       3. kill<job-id>
       4. events<job-id>
26. Mention any four commands options in hadoop?
       1. namenode-format
       2. secondarynamenode
       3. namenode
       4. datanode
       5. oiv
27. What is the task of the namenode?
        It is used to manage the HDFS in hadoop framework
28. What are the types of terminology there in map reduce?
            1. payload
            2. mapper
            3. namenode
            4. datanode
            6. slavenode
            7. job tracker
            8. task tracker
29. Is it Hadoop handle the streaming data?
      Yes. By using apache spark, apache kafka, apache flume hadoop handle the streaming data.
30. In hadoop namenode is a hardware product or not?
        No. In a hadoop framwork namenode is not a hardware product
31. Mentions the characteristics of Big data?
            1. By using hadoop we can able to mange the high volume of data
            2.  Velocity is high.Here it is a posible to analyzing millions of records.
            3. It is used to mange the different variety of data like image,audio,video
32. If the Namenode is down in hadoop what is the effect?
          If your namenode is down the cluster is automatically will be OFF in the hadoop environment.
33. What is the reason behind for using the hadoop?
          1.For instant approaching in a mobile
          2. suitable for all browsers
          3. Design is flexible
          4. Javascript plugins
34. What are the various dimesnsions of big data?
            1. Volatility
            2. validity
            3. Veracity
            4. Volume
            5. Velocity
35. Mentions some important hadoop tools to consuming big data?
          1. HDFS
          2. Hbase
          3. HIVE
          4. Sqoop
          5. Zookeeper
          6. NoSQL
          7. Mahout