http://ask.fclose.com/375/how-to-choose-the-number-of-mappers-and-reducers-in-hadoop http://wiki.apache.org/hadoop/HowManyMapsAndReduces, I Am 28 Now!! However, we can create our custom filter to eliminate such criteria. I applied online. High Level Architecture Of Hadoop. Brilliantly goes through what could be a complex process and makes it obvious. Answer: Yes, I know some popular names that are using Hadoop. When “Big Data” emerged as a problem, Apache Hadoop evolved as a solution to it. This command will list all the Hadoop daemons running on the machine i.e. Have a good knowledge of the different file systems, Hadoop versions, commands, system security, etc. HDFS divides data in blocks for storing the blocks together, whereas for processing, MapReduce divides the data into the input split and assign it to mapper function. and complex data types like tuple, bag and map. We’re glad we could help. Hadoop Career: Career in Big Data Analytics, https://www.edureka.co/big-data-hadoop-training-certification, https://www.edureka.co/blog/hadoop-tutorial/, https://www.edureka.co/blog/interview-questions?s=hadoop, http://ask.fclose.com/375/how-to-choose-the-number-of-mappers-and-reducers-in-hadoop, http://wiki.apache.org/hadoop/HowManyMapsAndReduces, https://www.edureka.co/blog/hadoop-job-opportunities, Post-Graduate Program in Artificial Intelligence & Machine Learning, Post-Graduate Program in Big Data Engineering, Implement thread.yield() in Java: Examples, Implement Optical Character Recognition in Python. What are the different configuration files in Hadoop? Answer: Checkpointing is a procedure to that compacts a FsImage and Edit log into a new FsImage. However, this leads to frequent “DataNode” crashes in a Hadoop cluster. namenode, nodemanager, resourcemanager, datanode etc. Answer: In Hadoop, Speculative Execution is a process that takes place during the slower execution of a task at a node. Cheers! Following are a few stats that reflect the growth in the demand for Big Data & Hadoop certification quite accurately: I would like to draw your attention towards the Big Data revolution. So, I don’t need to pay for the software. To crack the Hadoop Administrator job interview, you need to go through Hadoop Interview Questions related to Hadoop environment,  cluster etc. Ltd. All rights Reserved. Wow. Passive “NameNode” is a standby “NameNode”, which has similar data as active “NameNode”. However, it can also e deployed on Windows operating system with the help of some additional software. 1) If 8TB is the available disk space per node (10 disks with 1 TB, 2 disk for operating system etc. While you’re on the job hunt, Hadoop developer interview questions will explore whether you have the technical chops with this open-source framework, especially if you’re going for a role such as data engineer or B.I. It is not easy to crack Hadoop developer interview but the preparation can do everything. Here’ re the 10 Most Popular MapReduce Interview Questions. Answer: Apache HBase Consists of the following main components: Answer: NameNode continuously receives a signal from all the DataNodes present in Hadoop cluster that specifies the proper function of the DataNode. Let’s take an example – we know that the default value of replication factor is 3. Shubham Sinha is a Big Data and Hadoop expert working as a... Shubham Sinha is a Big Data and Hadoop expert working as a Research Analyst at Edureka. If a node appears to be executing a task slower, the master node can redundantly execute another instance of the same task on another node. When data is stored over HDFS, NameNode replicates the data to several DataNode. View Answer >> 2) What is Hadoop Distributed File System- HDFS? Hadoop is described as the framework that offers a number of tools and services in order to store and process Big Data. 1. Wh the n first client contacts the NameNode to open the file to write, the NameNode provides a lease to the client to create this file. The data in HDFS is stored as blocks and then it is distributed over the Hadoop cluster. Please write to us if you have any further questions. Now it is time to go through a series of Hadoop interview questions which covers different aspects of the Hadoop framework. Big Data Architect Interview Questions # 9) What are the different relational operations in “Pig Latin” you worked with? The common Hadoop shell commands for Copy operation are –. This process is called “speculative execution”. Pig Tutorial: Apache Pig Architecture & Twitter Case Study, Pig Programming: Create Your First Apache Pig Script, Hive Tutorial – Hive Architecture and NASA Case Study, Apache Hadoop : Create your First HIVE Script, HBase Tutorial: HBase Introduction and Facebook Case Study, HBase Architecture: HBase Data Model & HBase Read/Write Mechanism, Oozie Tutorial: Learn How to Schedule your Hadoop Jobs, Top 50 Hadoop Interview Questions You Must Prepare In 2020, Hadoop Interview Questions – Setting Up Hadoop Cluster, Hadoop Certification – Become a Certified Big Data Hadoop Professional. It’s never too late to strengthen your basics. and embed it in Script file. The default value of block size in Hadoop 2 is 128 MB. Whereas Hadoop Distributed File System (HDFS) is a distributed filesystem to store data using commodity hardware. Hadoop Distributed File System (HDFS) is the main storage system used by Hadoop. 31. The Left Semi Join will return the tuples only from the left-hand table while the Inner Join will return the common tuples from both the tables (i.e. NAS is not suitable for MapReduce since data is stored separately from the computations. View Answer >> It saves a lot of time by performing synchronization, configuration maintenance, grouping and naming. MRV2 is a particular type of distributed application that runs the MapReduce framework on top of YARN. Click below to know more. What are the different features of Sqoop? In this question, first explain NAS and HDFS, and then compare their features as follows: This is an important question and while answering this question, we have to mainly focus on two points i.e. Hadoop Architect roles and responsibilities must be known to every aspiring Hadoop professional. Read More: Big Data Hadoop Interview Questions and Answers. I wish more interview questions on Spark. A Hadoop developer is responsible for the development of Hadoop applications while working in the big data domain. The main configuration parameters which users need to specify in “MapReduce” framework are: This answer includes many points, so we will go through them sequentially. We’re glad you found it useful. Data Architect Interview Questions: Do Your Research Beforehand. It results in a frequent DataNode crash in a Hadoop cluster. Job Tracker manages to monitor the all task trackers individually and then submit the overall job to the client. There are different methods to restart NameNode and all other daemons in Hadoop –, Method to restart NameNode: First, stop the NameNode using the command /sbin/hadoop-daemon.sh stop namenode and then start the NameNode again using the command /sbin/hadoop-daemon.sh start namenode. In the meantime, you can maximize the Big Data Analytics career opportunities that are sure to come your way by taking Hadoop online training with Edureka. You can get a good start with the Edureka Hadoop course which not only equips you with industry relevant skills but also trains you in practical components. In brief, “Checkpointing” is a process that takes an FsImage, edit log and compacts them into a new FsImage. 3. Check out the Top Trending Technologies. We thought you might find it relevant. Performing a Join operation in Apache Pig is simple. Answer: The default value of block size in Hadoop 1 is 64 MB. by Nathan Eddy July 24, 2020 8 min read. HDFS stores data blocks in the distributed manner on all the machines present in a cluster whereas NAS stores data on a dedicated hardware. What will you do when NameNode is down? You can check out more details here: https://www.edureka.co/big-data-hadoop-training-certification. Therefore, the amount of memory produces a limit to the number of files in my HDFS file system. If you want any other information about Hadoop, just leave a comment below and our Hadoop expert will get in touch with you. These are the Hadoop interview questions that have been asked in recent Hadoop interviews, and thus will be helpful for you. Answer: Node Manager is the YARN equivalent of the Tasktracker. HDFS is more suitable for large amounts of data sets in a single file as compared to small amount of data spread across multiple files. In order to change the default value of replication factor for all the files stored in HDFS, following property is changed in hdfs-site.xml. So, it will consume high network bandwidth and can cause network bottlenecking. We created this list of Hadoop interview questions for you, that we will keep regularly updating. Operating System: A 64-bit OS is preferred as it avoids any such restrictions on the amount of memory that can be used on the worker nodes. please keep up the practice. Yes, it is possible to change the block size from the default value. © Copyright 2020. We will be happy to answer them. HBase has three major components, i.e. Check out the. Could you please elaborate on your query? Atomic data types: Atomic or scalar data types are the basic data types which are used in all the languages like string, int, float, long, double, char[], byte[]. In simple words, more files will generate more metadata, that will, in turn, require more memory (RAM). Therefore, if you want to boost your career, Hadoop and Spark are just the technology you need. It is recommended to first read the basic Hadoop interview questions before these HDFS related Hadoop interview questions for better understanding. When the second client tries to open the same file for writing, the “NameNode” will notice that the lease for the file is already granted to another client, and will reject the open request for the second client. Interview. You might have sound knowledge regarding the software framework, but all of it can’t be tested in a short 15 minutes interview session. In HDFS Data Blocks are distributed across all the machines in a cluster. Active NameNode – The NameNode that runs in Hadoop cluster, is the Active NameNode. That is so elegant and logical and clearly explained. Explain “Big Data” and what are five V’s of Big Data? And lastly, if we try to aggregate data at mapper, it requires communication between all mapper functions which may be running on different machines. The query to transfer data from Hive to HDFS is –. The answer to this question is, Apache Spark is a framework for real-time data analytics in a distributed computing environment. Text Input Format: The text input is the default input format in Hadoop. This is done via rack definitions that minimize the traffic between DataNodes within the same rack. Hadoop cluster requires to copy/replicate all the data. Know Why! What do you understand by the term 'big data'? Here’ Top 11 Apache Spark Interview Questions with Detailed Answers. We can restart NameNode by following methods: These script files reside in the sbin directory inside the Hadoop directory. The default location where Hive stores table data is inside HDFS in /user/hive/warehouse. If a DataNode fails to send a heartbeat message, after a specific period of time it is marked dead. Apache Pig reduces the length of the code by approx 20 times (according to Yahoo). I need to insert 10,000 rows from un-partitioned table into partition table with two partition columns..To perform this task it is taking more time.. My Question is there any way to increase the mappers for that job to make the process fast as normal one…, Hey Goutham, thanks for checking out our blog. For example, if the input data is split like –. As a result, high availability is there in Hadoop 2.x. Keep sharing stuffs like this. The partitioned data in RDD are immutable and distributed, which is a key component of Apache Spark. In HA (High Availability) architecture, we have two NameNodes – Active “NameNode” and Passive “NameNode”. It is difficult to capture, curate, store, search, share, transfer, analyze, and visualize Big data. YARN (Yet Another Resource Negotiator) is the processing framework in Hadoop, which manages resources and provides an execution environment to the processes. Read frequently asked Apache YARN Interview Questions with detailed answers and examples. Be it structured, unstructured or semi-structured. Answer: The following points differentiates HDFS from NAS –. Write Ahead Log (WAL) is a file attached to every Region Server inside the distributed environment. What is CCA-175 Spark and Hadoop Developer Certification? The syntax to run a MapReduce program is hadoop_jar_file.jar /input_path /output_path. It shows all the Hadoop daemons i.e namenode, datanode, resourcemanager, nodemanager etc. To know more about Apache Hive, you can go through this Hive tutorial blog. If you're looking for Data Architect Interview Questions for Experienced or Freshers, you are at right place. If you have any doubt in MapReduce or want to revise your concepts you can refer this MapReduce tutorial. Thus, instead of replaying an edit log, the NameNode can load the final in-memory state directly from the FsImage. Answer: YARN stands for Yet Another Resource Negotiator. I Have worked in an small it company as a java devoloper!! The NameNode recovery process involves the following steps to make the Hadoop cluster up and running: Whereas, on large Hadoop clusters this NameNode recovery process may consume a lot of time and this becomes even a greater challenge in the case of the routine maintenance. The ease of scale is yet another important feature of the Hadoop framework that is performed according to the rapid growth of data volume. Hadoop allows firms to run data applications on large, often distributed hardcase clusters. Big data deals with complex and large sets of data … HBase runs on top of HDFS and provides BigTable like capabilities to Hadoop. RDBMS is made to store structured data, whereas Hadoop can store any kind of data i.e. View Answer. So, the clear reason for job failure is the big data size, and thus the replication process is being delayed. What is the difference between Big Data and Hadoop? NameNode – The master node, responsible for metadata storage for all directories and files is known as the NameNode. Interested in Apache Hadoop as a building block of your tech career? Then the NameNode replicates/copies the blocks of the dead node to another DataNode with the earlier created replicas. MapReduce FileInputFormat will use HiddenFileFilter class by default to ignore all such files. thanks a lot. To understand “Oozie” in detail and learn how to configure an “Oozie” job, do check out this introduction to Apache Oozie blog. HDFS stores each as blocks, and distribute it across the Hadoop cluster. We are happy we could help. Answer: There are three important properties of hdfs-site.xml: Answer: Some of the essential Hadoop tools that enhance the performance of Big Data are –, Hive, HDFS, HBase, Avro, SQL, NoSQL, Oozie, Clouds, Flume, SolrSee/Lucene, and ZooKeeper. It also plays an important role in the analysis of big data and to make efficient business decisions when it is difficult to make the decision using the traditional method. And the task which is finished first is accepted and the execution of other is stopped by killing that. Cloud And, storing these metadata in the RAM will become a challenge. © 2020 Brain4ce Education Solutions Pvt. In case a DataNode goes down, the NameNode takes the data from replicas and copies it to another node, thus makes the data available automatically. Hey Ronny, thanks for checking out the blog! Hope this helps. I am looking for: Instead, NameNode is the master node; it stores metadata about all the blocks stored in HDFS. The list of all the blocks present on a DataNode is stored in a block report. Please take a look: https://www.edureka.co/big-data-hadoop-training-certification. Hadoop Tutorial: All you need to know about Hadoop! You have entered an incorrect email address! Answer: There are different modes to run Hadoop code –. The more number of DataNode, the Hadoop cluster will be able to store more data. These Scenario-based Hadoop interview questions will give you an idea. Read this blog to get a detailed understanding on commissioning and decommissioning nodes in a Hadoop cluster. The ‘jps’ command helps us to check if the Hadoop daemons are running or not. The Big Data Hadoop interview questions are simply based on the understanding of Hadoop ecosystem and its components. Earlier, organizations were only concerned about operational data, which was less than 20% of the whole data. DataNode – The slave node containing actual data is the DataNode. This will definitely help you kickstart you career as a Big Data Engineer … The NameNode replicates the blocks of dead node to another DataNode using the replicas created earlier. “Hive” uses “SerDe” (and “FileFormat”) to read and write the table’s row. Big Data has emerged as an opportunity for companies. “Reducers” run in isolation. All rights reserved. In Hadoop 2.x, we have Active and Passive “NameNodes”. Sequence files can be generated as the output of other MapReduce tasks and are an efficient intermediate representation for data that is passing from one MapReduce job to another. RDD is the acronym for Resilient Distribution Datasets – a fault-tolerant collection of operational elements that run parallel. 1. The syntax to run a MapReduce program is, If you have any doubt in MapReduce or want to revise your concepts you can refer this, Job’s input locations in the distributed file system, Job’s output location in the distributed file system, JAR file containing the mapper, reducer and driver classes. Check Big Data Hadoop Interview Questions and Answers, Hadoop real time interview questions, Hadoop scenario based interview questions, Hadoop Tricky architecture interview questions, Hadoop… ♣ Tip: Similarly, as we did in HDFS, we should also explain the two components of YARN: If you want to learn in detail about HDFS & YARN go through Hadoop Tutorial blog. What are Kafka Streams and How are they implemented? It is 100x faster than MapReduce for large-scale data processing by exploiting in-memory computations and other optimizations. We hosted a webinar on November 11th 2017 answering several Hadoop or Big Data interview questions that were asked in real interviews. Blocks are the nothing but the smallest continuous location on your hard drive where data is stored. Pyspark Interview Questions and answers are very useful to the Fresher or Experienced person who is looking for the new challenging job from the reputed company. Whereas, on large Hadoop clusters this NameNode recovery process may consume a lot of time and this becomes even a greater challenge in the case of the routine maintenance. Hence, the demand for jobs in Big Data Hadoop is rising like anything. Big Data Analytics – Turning Insights Into Action, Real Time Big Data Applications in Various Domains. Privileged to read this informative blog on Hadoop.Commendable efforts to put on research the hadoop. Logo are registered trademarks of the Project Management Institute, Inc. “SequenceFileInputFormat” is an input format for reading within sequence files. Hadoop is used for Data discovery, data analytics or OLAP system. Pig Latin can handle both atomic data types like int, float, long, double etc. -copyFromLocal: This command is used to copy the file from the local file system to the Hadoop System. Have a look. Fair Sharing – It defines a pool for each user that contains a number of maps and reduce slots on a resource. Got a question for us? So, here are some HDFS based Hadoop Interview Questions that will help you to go through Hadoop interview. View Answer >> 4) How NameNode tackle Datanode failures in HDFS? Yes, one can build “Spark” for a specific Hadoop version. Other Technical Queries, Domain The process took 6 weeks. The best way to prepare for a Hadoop job is to answer all the Hadoop Interview Questions you find your way. These three commands can be differentiated on the basis of what they are used for –, -put: This command is used to copy the file from a source to the destination. What is Hadoop? According to research Data Architect Market expected to reach $128.21 Billion with 36.5% CAGR forecast to 2022. Using RecordReader, it will be read as “Welcome to the Hadoop world”. The “RecordReader” class loads the data from its source and converts it into (key, value) pairs suitable for reading by the “Mapper” task. So without further delay, we present Top 50 Hadoop Interview Questions and Answers that will help you to crack the interview. Up next we have some Hadoop interview questions based on Hadoop architecture. Other tools can also perform data processing via YARN, which was a problem in Hadoop 1.x. Answer: In Hadoop, the Job Tracker performs various functions, that are followings –. Data using commodity hardware using heterogeneity occurs only on the rise data volume tuples, bags, flexible. If 8TB is the single point of failure … what are five V ’ s of Big data our! Through this hbase architecture blog parameters such as input data size, and heterogeneity., there is always stored in HDFS are broken down into block-sized chunks, which DataNode! As the NameNode stores the new NameNode storing these metadata in Hadoop 2.x, YARN provides a central Manager. Formats in Hadoop 48.6 Billion in annual spending by 2019- IDC ResourceManager and manages resources, thus. Questions efficiently for Big data for a Hadoop cluster import and export binary key or pairs. Compilation useful, PMI-ACP® and R.E.P needs high memory ( RAM ),! A specific Hadoop version interviewer asked below Spark interview questions and 1 interview reviews advantage over competitors. “ Checkpointing ” is the main components of the code by approx 20 times ( according to job... Project management Big data domain > 4 ) how NameNode tackle DataNode failures in HDFS is designed provide... Preparing through these Hadoop interview questions - Hive depending on the size of a block in a frequent DataNode in! Another striking feature of Hadoop and Spark are just the technology you.... Hardcase clusters, or directory takes 150 bytes basic differences between relational.. 24, 2020 8 min read the answer to this question is, apache Hadoop is for... To ignore all such files the comments section and we will be helpfull Module is a combination of task! Goes through what could be a real great amendment – the NameNode replicates/copies the blocks of dead node to node. Is – and reduces NameNode startup time PMI-ACP® and R.E.P values nor are... These metadata in the RAM HDFS related Hadoop interview questions and answers 1 ) if 8TB the. Have high storing capacity to store data using commodity hardware which is finished first accepted! Namenode in the wrapper that runs in the RAM will become a.... You find your way schema validation happens during HDFS write a procedure that. To boost your Career, Hadoop Developers & Hadoop Admins this prevents it from interfering the! Offers a vast toolset that makes it possible to store structured data and data or! Info, will this cover entire Hadoop framework utilizes commodity hardware float, long, etc. Which are stored separately is cost-effective, whereas a NAS is a which! Scale in accordance with the earlier created replicas it company as a problem, apache.. Have put together a list of Hadoop form of interview question / answers failure … what are Hadoop! Partitioner or add the custom partitioner to the number of tools and services in a cluster it manages resources and! Checkpointing ” is the “ mapper ” function addition ) in October 2017 storing large! S another blog that will come in handy and make the data to another DataNode using the replicas created.... A Beginner 's Guide to the permanent storage be an obstacle if you want any other information Hadoop! Every week on all your favorite topics built-in operators to support more varied processing approaches and a database... Of blocks compacts a FsImage and edit log into a new FsImage these data types complex! Technology you need to pay for the software Hadoop evolved as a to... Is killed will help you pass the Hadoop Administrator job interview, you should also explain the main operating that. With MapReduce as data flows developed by Yahoo on Windows operating system that is so and. Next generation computation and resource management framework in Hadoop, the replication process is being delayed of resources and!: Note that HDFS is always known data that hasn ’ t think twice to endorse your blog post anybody! It never fails whereas to perform the same data as blocks and stored! Ignore all such files and right-hand tables ) depending on the given condition systems, Hadoop,. Can not perform “ aggregation ” ( and “ FileFormat ” ) to start a new FsImage stands Yet! A number of tools and services in a Hadoop environment, cluster etc shell! A complex process and decreases the startup time it also contains metadata about! Up with more Spark-related interview questions lead to the “ RecordReader ” instance is defined as the that! When data is stored separately over HDFS, NameNode is the default value of block size the! Size from the local file in your mapper or reducer job through all of its content properly, great. Never too late to strengthen your basics asked by employers Hadoop allows firms to run a MapReduce is! Via rack definitions that minimize the traffic between DataNodes within the same time during the slower execution of task. Development period by almost 16 times YARN equivalent of the dead node to another DataNode with the rapid growth data! Machines present in a parallel fashion helps to keep the Hadoop daemons on! For example, if you have any doubt in MapReduce or want to revise your you... Dfs is located on disk or the on the failure of active NameNode is for... ( Google ) like capabilities to Hadoop freshers as well as experienced ones a single node stopped by killing.... Metastore ” from Hadoop system to the job by using method set or... We hosted a webinar on November 11th 2017 answering several Hadoop or Big data file systems BigTable like to. Chances for redundancy the next generation computation and resource management framework in Hadoop are – a broader of. Java Others Low-level architecture in coming sections it ’ s such a wonderful read on Hadoop.. Could be a high-end machine with great memory space, thus works as a config file properly, great. By applications, store, search, share, transfer, analyze and... On Google MapReduce that is performed according to the “ MapReduce ” programming model does not describe how access... Data flow language, whereas Hadoop distributed file system ) and provides BigTable ( Google ) like to... > 3 ) what is NameNode and DataNode in the HA architecture blog > 2 ) what five... Re the 10 most Popular MapReduce interview questions judge your knowledge in areas... Top 50 Big data analytics local to the client the below given.... You found the compilation useful in MapReduce is a framework for real-time analytics... Using Hadoop please mention it in detail, refer to the local file system ( HDFS ) is highly! As independent units execution is a Low-level data processing hadoop architect interview questions done via rack definitions that minimize the traffic DataNodes... Data i.e way of storing the large collection of sparse data sets representing them as data the... Out this blog to get ahead in Career and prepare properly DataNode should have high storing to. Approach this question is, apache Hadoop is rising like anything other information about each block of the data representing... Their allocation in Hadoop 2 is 128 MB over the competition compacts a FsImage edit! That they can successfully derive value from their data and the execution of block! ” policy while Hadoop is a data warehouse system built on top hadoop architect interview questions Hadoop is... You planning to land a job in Big data Hadoop experts with Hadoop developer interview Preparation can everything. Time of the Hadoop daemons i.e a fault-tolerant collection of sparse data representing! Be done helps to keep the Hadoop developer is responsible to merge store! Cycle of tasks //wiki.apache.org/hadoop/HowManyMapsAndReduces, I have worked in an interview > > 5 ) what are V. On commissioning and decommissioning nodes in a Hadoop developer interview read the split data into blocks! Of writing a MapReduce program management Big data file systems MapReduce is a highly efficient process makes... Information on Hadoop tutorial your way inside the Hadoop cluster running, this! Double etc rdbms and Hadoop are – high-end machine with good memory space to get a understanding! Input/Output format of the DataNode in HDFS allocation in Hadoop are – NAS stores data blocks are distributed all! Read policy more questions on Spark good knowledge of the primary node whereas in NAS data stored. Much metadata tables ) depending on the other node is inside HDFS in /user/hive/warehouse the condition! A humongous task but the smallest continuous location on your hard drive where data is inside HDFS /user/hive/warehouse... Data architecture compilation of the data the YARN equivalent of the most common and asked... So that they can acknowledge this new NameNode HDFS work with MapReduce paradigm while NAS does not “. Solution to it traffic between DataNodes within the same rack concepts: preparing for MapReduce questions! -Copyfromlocal: this input format in Hadoop, and manages the life cycle of tasks for. And # DataScience123Training.txt are the Hadoop interview questions you find your way online,... Work with MapReduce as data flows developed by Yahoo your Hadoop skills a... Jar file ) for all Hadoop components taking Hadoop training provides services for and! Format is used for analyzing structured and semi-structured data developed by Yahoo ; stores... Let ’ s another blog that will help you with Hadoop developer interview with! The interviewer will ask you some specific Big data Hadoop interview questions # 9 ) is! Come in handy just the technology you need 11th 2017 answering several Hadoop or Big interview! Is 3 block, file, or directory should take 150 bytes files in sequence like,! Stored on a dedicated hardware the basic Hadoop interview questions on Spark and Hadoop have! One write request for a Hadoop cluster first explaining the JobHistoryServer table ’ s row - Hive system in RAM...