All the data nodes put together form a storage area i.e. the physical location of the data nodes is referred to as Rack in HDFS. The rack information i.e. the rack id of each data node is acquired by the NameNode. The process of selecting closer data nodes depending on the rack information is known as Rack Awareness.
The contents present in the file are divided into data block as soon as the client is ready to load the file into the hadoop cluster. After consulting with the NameNode, client allocates 3 data nodes for each data block. For each data block, there exists 2 copies in one rack and the third copy is present in another rack. This is generally referred to as the Replica Placement Policy.
Posted Date:- 2021-11-01 08:37:12
Name the common input formats in Hadoop.
What happens to a NameNode that has no data?
What is a rack awareness and on what basis is data stored in a rack?
Explain about the indexing process in HDFS.
What are the challenges in the Virtualization of Big Data testing?
Explain Rack Awareness in Hadoop.
Name some outlier detection techniques.
How are Big Data and Data Science related?
Which language is preferred for Big Data - R, Python or any other language?
What are the challenges in Automation of Testing Big data?
Name the three modes in which you can run Hadoop.
What is the process to change the files at arbitrary locations in HDFS?
Talk about the different tombstone markers used for deletion purposes in HBase.
Explain the core methods of a Reducer.
What are some of the data management tools used with Edge Nodes in Hadoop?
What are Edge Nodes in Hadoop?
What is the difference Big data Testing vs. Traditional database Testing regarding Infrastructure?
What do you mean by indexing in HDFS?
Explain the different features of Hadoop.
What do you mean by Performance of the Sub - Components?
Explain about the process of inter cluster data copying.
What is Data Processing in Hadoop Big data testing?
What is a block and block scanner in HDFS?
What are the steps involved in deploying a big data solution?
What are the most commonly defined input formats in Hadoop?
What is the best hardware configuration to run Hadoop?
What is "MapReduce" Validation?
What do you understand by Data Staging?
How is data quality being tested?
Name the different commands for starting up and shutting down Hadoop Daemons.
What is the purpose of the JPS command in Hadoop?
What are the main components of a Hadoop Application?
Define and describe the term FSCK.
What do you mean by commodity hardware?
Differentiate between Structured and Unstructured data.
How big data analysis helps businesses increase their revenue? Give example.
Define HDFS and YARN, and talk about their respective components.
How is big data analysis helpful in increasing business revenue?
How is Hadoop related to Big Data?