InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Why is Checkpointing Important in Hadoop? |
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| 2. |
Can Hadoop handle streaming data? |
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| 3. |
What is speculative execution in Hadoop? |
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| 4. |
What are Problems with small files and HDFS? |
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| 5. |
Suppose Hadoop spawned 100 tasks for a job and one of the task failed. What will Hadoop do? |
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| 6. |
Consider case scenario: In M/R system, - HDFS block size is 64 MB |
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| 7. |
What is a Combiner? |
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| 8. |
What does "file could only be replicated to 0 nodes, instead of 1" mean? |
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| 9. |
What happens when two clients try to write into the same HDFS file? |
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| 10. |
Can we search for files using wildcards? |
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| 11. |
How to make a large cluster smaller by taking out some of the nodes? |
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| 12. |
What happens if one Hadoop client renames a file or a directory containing this file while another client is still writing into it? |
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| 13. |
Does the name-node stay in safe mode till all under-replicated files are fully replicated? |
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| 14. |
How do you gracefully stop a running job? |
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| 15. |
The requirement is to add a new data node to a running Hadoop cluster; how do I start services on just one data node? |
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| 16. |
Is there a hdfs command to see available free space in hdfs |
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| 17. |
Which file does the Hadoop-core configuration? |
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| 18. |
What is rack awareness? |
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| 19. |
Default replication factor to a file is 3. |
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| 20. |
Copy a directory from one node in the cluster to another |
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| 21. |
Why ‘Reading‘ is done in parallel and ‘Writing‘ is not in HDFS? |
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| 22. |
Explain how do ‘map’ and ‘reduce’ works. |
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| 23. |
What is a Secondary Namenode? Is it a substitute to the Namenode? |
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| 24. |
What is a rack? |
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| 25. |
What is the communication channel between client and namenode/datanode? |
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| 26. |
Are job tracker and task trackers present in separate machines? |
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| 27. |
How indexing is done in HDFS? |
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| 28. |
What are the benefits of block transfer? |
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| 29. |
What is a ‘block’ in HDFS? |
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| 30. |
What is a heartbeat in HDFS? |
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| 31. |
What is a task tracker? |
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| 32. |
What is a job tracker? |
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| 33. |
Why do we use HDFS for applications having large data sets and not when there are lot of small files? |
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| 34. |
What is a Datanode? |
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| 35. |
Is Namenode also a commodity hardware? |
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| 36. |
What is a Namenode? |
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| 37. |
Since the data is replicated thrice in HDFS, does it mean that any calculation done on one node will also be replicated on the other two? |
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| 38. |
Replication causes data redundancy, then why is it pursued in HDFS? |
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| 39. |
What is Fault Tolerance? |
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| 40. |
What is the basic difference between traditional RDBMS and Hadoop? |
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| 41. |
Why do we need Hadoop? |
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| 42. |
How is analysis of Big Data useful for organizations? |
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| 43. |
What are the four characteristics of Big Data? |
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| 44. |
What is Big Data? |
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| 45. |
What happens to job tracker when Namenode is down? |
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| 46. |
What if a Namenode has no data? |
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| 47. |
What does /etc /init.d do? |
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| 48. |
Which are the three modes in which Hadoop can be run? |
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| 49. |
How to restart Namenode? |
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| 50. |
What does ‘jps’ command do? |
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