Well, if you are looking for Hadoop HDFS interview questions and aspire to become a Hadoop Certified Developer from the Hadoop Course or a Hadoop Certified Admin from the Hadoop Admin Course, you have come to the right place. This list of interview questions on HDFS will prepare you to match the expectations of the employer. Before moving ahead in this Hadoop HDFS Interview Questions blog, let us know about the trends and demands in the field of Hadoop.
- What are the different vendor-specific distributions of Hadoop? …
- What are the different Hadoop configuration files? …
- What are the three modes in which Hadoop can run? …
- What are the differences between regular FileSystem and HDFS? …
- Why is HDFS fault-tolerant? …
- Explain the architecture of HDFS.
HDFS interview Questions and Answers |Hadoop| Bigdata|
11. What are the basic characteristics of Hadoop?
Written in Java, Hadoop framework has the capability of solving issues involving Big Data analysis. Its programming model is based on Google MapReduce and infrastructure is based on Google’s Big Data and distributed file systems. Hadoop is scalable and more nodes can be added to it.
Get to know the history, timeline and architecture of Hadoop!
19. What is meant by streaming access?
HDFS works on the principle of “write once, read many” and the focus is on fast and accurate data retrieval. Steaming access refers to reading the complete data instead of retrieving single record from the database.
21. Which one is the master node in HDFS? Can it be commodity?
Name node is the master node in HDFS and job tracker runs on it. The node contains metadata and works as high availability machine and single pint of failure in HDFS. It cannot be commodity as the entire HDFS works on it.
25. What is the role played by task trackers?
Daemons that run on What data nodes, the task tracers take care of individual tasks on slave node as entrusted to them by job tracker.
Learn more about HDFS in this Hadoop Developer Training Course to get ahead in your career!
10. What are the characteristics of data scientists?
Data scientists analyze data and provide solutions for business problems. They are gradually replacing business and data analysts.
Most Valuable Data Science Skills Of 2020 to learn more about must-have Data Science skills.
27. Can multiple clients write into an HDFS file concurrently?
No, multiple clients can’t write into an HDFS file concurrently. HDFS follows single writer multiple reader model. The client which opens a file for writing is granted a lease by the NameNode. Now suppose, in the meanwhile, some other client wants to write into that very file and asks NameNode for the write permission. At first, the NameNode will check whether the lease for writing into that very particular file has been granted to someone else or not. Then, it will reject the write request of the other client if the lease has been acquired by someone else, who is currently writing into the very file.
28. What is meant by ‘block’ in HDFS?
Block in HDFS refers to minimum quantum of data for reading or writing. Default block size is 64 MB in HDFS. If a file is 52 MB then HDFS would store it and leave 12 MB empty and ready to use.
