Hadoop Developer Interview Questions
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Hadoop Developer interview questions shared by candidates
Mostly about Hadoop technologies HDFS, MapReduce, Hbase, Hive.
2 Answers↳
Answered almost all questions
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Hello, Thank you for your interest in Nisum and taking the time to provide feedback. We take all input very seriously here at Nisum, and would like to take this opportunity to help clarify the situation you've referenced. As we discussed and was conveyed to you, Nisum (like many other firms looking for excellent talent) believes in offering the best offer to a candidate after a thorough technical and behavioral assessment. After our evaluation, we found that there was misalignment in expectations between parties. Your expectations seemed to be based on hearsay about working on the west coast. There was also an apparent mismatch between your current views as a contractor versus joining as a full time employee. Finally, we did not say that "you are eligible for less salary." A formal offer was never extended as we could not meet each other's expectations. We apologize if you believe that the interview process was not as you'd hoped. Again, thank you for your interest in Nisum Technologies! Wishing you the best! Nisum HR Less
I was not asked even a single proper technical question. It was more so like an hr round.
Describe how you implemented MapReduce jobs Describe what data is generated when you run a MR/Tez job Which file format is best to store files in?
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Best file format (at the time) was ORC as it was compressed and not cleartext/flat file. Parquet is also a good option and is now considered standard (this was before Delta). Less
CAP theorem
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n theoretical computer science, the CAP theorem, also named Brewer's theorem after computer scientist Eric Brewer, states that it is impossible for a distributed data store to simultaneously provide more than two out of the following three guarantees: Consistency. Availability. Partition tolerance. Less
general questions on Hadoop, and some use case based questions
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standard generic answers, stick to the basics
Hive Static partition vs Dynamic partition
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Insert input data files individually into a partition table is Static Partition, fast, can alter the partition, set hive.mapred.mode = strict Single insert to partition table is known as a dynamic partition, slow, can’t perform alter, don’t know how many columns Less