Hadoop 1 MCQs
Q.1 What should be the first step if a block of data is missing or corrupt in HDFS?
A. Run fsck command to identify and fix
B. Restart the NameNode
C. Reformat the DataNode
D. Ignore the error
Q.2 How can you view the list of blocks and their locations for a file in HDFS?
A. hadoop fsck -files -blocks -locations
B. hadoop fs -check
C. hadoop fs -filestatus
D. hadoop fs -blockinfo
Q.3 Which command is used to set the replication factor for a file in HDFS?
A. hadoop fs -setrep
B. hadoop fs -replicate
C. hadoop fs -replicationFactor
D. hadoop fs -setReplication
Q.4 How do you display the last kilobyte of a file in HDFS?
A. hadoop fs -tail
B. hadoop fs -end
C. hadoop fs -last
D. hadoop fs -showtail
Q.5 What is the default HDFS command to create a directory?
A. hadoop fs -mkdir
B. hadoop fs -createDir
C. hadoop fs -makeDir
D. hadoop fs -newDir
Q.6 Which factor influences the block size in HDFS?
A. The amount of RAM available
B. The type of data being stored
C. The total storage capacity of the cluster
D. The network bandwidth
Q.7 What is the role of the Secondary NameNode in HDFS?
A. To replace the primary NameNode in case of failure
B. To take over data node responsibilities
C. To periodically merge changes to the FS image with the edit log
D. To store secondary copies of data
Q.8 What type of data write operation does HDFS optimize for?
A. Random writes
B. Sequential writes
C. Simultaneous writes
D. Indexed writes
Q.9 How does HDFS handle very large files?
A. By breaking them into smaller parts and distributing them
B. By compressing them
C. By ignoring them
D. By storing them on a single node
Q.10 Which data storage method is used by HDFS to enhance performance and fault tolerance?
A. Data mirroring
B. Data replication
C. Data striping
D. Data encryption
Q.11 What is a fundamental characteristic of HDFS?
A. Fault tolerance
B. Speed optimization
C. Real-time processing
D. High transaction rates
Q.12 When a DataNode is reported as down, what is the first action to take?
A. Restart the DataNode
B. Check network connectivity to the DataNode
C. Delete and reconfigure the DataNode
D. Perform a full cluster reboot
Q.13 What should you check first if the NameNode is not starting?
A. Configuration files
B. DataNode status
C. HDFS health
D. Network connectivity
Q.14 What is the purpose of the hadoop balancer command?
A. To balance the load on the network
B. To balance the storage usage across the DataNodes
C. To upgrade nodes
D. To restart failed tasks
Q.15 Which command can you use to check the health of the Hadoop file system?
A. fsck HDFS
B. hadoop fsck
C. check HDFS
D. hdfs check
Q.16 How do you list all nodes in a Hadoop cluster using the command line?
A. hadoop dfsadmin -report
B. hadoop fs -ls nodes
C. hadoop dfs -show nodes
D. hadoop nodes -list
Q.17 What mechanism allows Hadoop to scale processing capacity?
A. Adding more nodes to the network
B. Increasing the storage space on existing nodes
C. Upgrading CPU speed
D. Using more efficient algorithms
Q.18 How does the Hadoop framework handle hardware failures?
A. Ignoring them
B. Re-routing tasks
C. Replicating data
D. Regenerating data
Q.19 Which type of file system does Hadoop use?
A. Distributed
B. Centralized
C. Virtual
D. None of the above
Q.20 In Hadoop, what is the function of a DataNode?
A. Stores data blocks
B. Processes data blocks
C. Manages cluster metadata
D. Coordinates tasks
Q.21 What role does the NameNode play in Hadoop Architecture?
A. Manages the cluster’s storage resources
B. Executes user applications
C. Handles low-level data processing
D. Serves as the primary data node
Q.22 Which component in Hadoop’s architecture is responsible for processing data?
A. NameNode
B. DataNode
C. JobTracker
D. TaskTracker
Q.23 Which command is used to view the contents of a directory in HDFS?
A. hadoop fs -ls
B. hadoop fs -dir
C. hadoop fs -show
D. hadoop fs -display
Q.24 Which programming model is primarily used by Hadoop to process large data sets?
A. Object-oriented programming
B. Functional programming
C. Procedural programming
D. MapReduce
Q.25 What mechanism does Hadoop use to ensure data is not lost in case of a node failure?
A. Data mirroring
B. Data partitioning
C. Data replication
D. Data encryption
Q.26 Which feature of Hadoop makes it suitable for processing large volumes of data?
A. Fault tolerance
B. Low cost
C. Single-threaded processing
D. Automatic data replication
Q.27 Hadoop can process data that is:
A. Structured only
B. Unstructured only
C. Semi-structured only
D. All of the above
Q.28 What type of architecture does Hadoop use to process large data sets?
A. Peer-to-peer
B. Client-server
C. Master-slave
D. Decentralized
Q.29 Which core component of Hadoop is responsible for data storage?
A. MapReduce
B. Hive
C. HDFS
D. YARN
Q.30 What is Hadoop primarily used for?
A. Big data processing
B. Web hosting
C. Real-time transaction processing
D. Network monitoring
Q.31 How does HBase provide fast access to large datasets?
A. By using a column-oriented storage format
B. By employing a row-oriented storage format
C. By using traditional indexing methods
D. By replicating data across multiple nodes
Q.32 In the Hadoop ecosystem, what is the role of Oozie?
A. Job scheduling
B. Data replication
C. Cluster management
D. Security enforcement
Q.33 What is the primary function of Apache Flume?
A. Data serialization
B. Data ingestion into Hadoop
C. Data visualization
D. Data archiving
Q.34 How does Pig differ from SQL in terms of data processing?
A. Pig processes data in a procedural manner, while SQL is declarative
B. Pig is static, while SQL is dynamic
C. Pig supports structured data only, while SQL supports unstructured data
D. Pig runs on top of Hadoop only, while SQL runs on traditional RDBMS
Q.35 Which tool in the Hadoop ecosystem is best suited for real-time data processing?
A. Hive
B. Pig
C. HBase
D. Storm
Q.36 What is Hive primarily used for in the Hadoop ecosystem?
A. Data warehousing operations
B. Real-time analytics
C. Stream processing
D. Machine learning
Q.37 If you notice that applications in YARN are frequently being killed due to insufficient memory, what should you adjust?
A. Increase the container memory settings in YARN
B. Upgrade the physical memory on nodes
C. Reduce the number of applications running simultaneously
D. Optimize the application code
Q.38 What should be your first step if a YARN application fails to start?
A. Check the application logs for errors
B. Restart the ResourceManager
C. Increase the memory limits for the application
D. Reconfigure the NodeManagers
Q.39 What command would you use to check the logs for a specific YARN application?
A. yarn logs -applicationId
B. yarn app -logs
C. yarn -viewlogs
D. yarn application -showlogs
Q.40 How can you kill an application in YARN using the command line?
A. yarn application -kill
B. yarn app -terminate
C. yarn job -stop
D. yarn application -stop
Q.41 Which command is used to list all running applications in YARN?
A. yarn application -list
B. yarn app -status
C. yarn service -list
D. yarn jobs -show
Q.42 How does YARN handle the failure of an ApplicationMaster?
A. It pauses all related jobs until the issue is resolved
B. It automatically restarts the ApplicationMaster
C. It reassigns the tasks to another master
D. It shuts down the failed node
Q.43 In YARN, what does the ApplicationMaster do?
A. Manages the lifecycle of an application
B. Handles data storage on HDFS
C. Configures nodes for the ResourceManager
D. Operates the cluster’s security protocols
Q.44 Which YARN component is responsible for monitoring the health of the cluster nodes?
A. ResourceManager
B. NodeManager
C. ApplicationMaster
D. DataNode
Q.45 What role does the NodeManager play in a YARN cluster?
A. It manages the user interface
B. It coordinates the DataNodes
C. It manages the resources on a single node
D. It schedules the reducers
Q.46 How does YARN improve the scalability of Hadoop?
A. By separating job management and resource management
B. By increasing the storage capacity of HDFS
C. By optimizing the MapReduce algorithms
D. By enhancing data security
Q.47 What is the primary function of the Resource Manager in YARN?
A. Managing cluster resources
B. Scheduling jobs
C. Monitoring job performance
D. Handling job queues
Q.48 What is an effective way to resolve data skew during the reduce phase of a MapReduce job?
A. Adjusting the number of reducers
B. Using a combiner
C. Repartitioning the data
D. Optimizing the partitioner function
Q.49 What common issue should be checked first when a MapReduce job is running slower than expected?
A. Incorrect data formats
B. Inadequate memory allocation
C. Insufficient reducer tasks
D. Network connectivity issues
Q.50 What does the WritableComparable interface in Hadoop define?
A. Data types that can be compared and written in Hadoop
B. Methods for data compression
C. Protocols for data transfer
D. Security features for data access
Q.51 What is the purpose of the Partitioner class in MapReduce?
A. To decide the storage location of data blocks
B. To divide the data into blocks for mapping
C. To control the sorting of data
D. To control which key-value pairs go to which reducer
Q.52 How do you specify the number of reduce tasks for a Hadoop job?
A. Set the mapred.reduce.tasks parameter in the job configuration
B. Increase the number of nodes
C. Use more mappers
D. Manually partition the data
Q.53 Which MapReduce method is called once at the end of the task?
A. map()
B. reduce()
C. cleanup()
D. setup()
Q.54 What happens if a mapper fails during the execution of a MapReduce job?
A. The job restarts from the beginning
B. Only the failed mapper tasks are retried
C. The entire map phase is restarted
D. The job is aborted
Q.55 What determines the number of mappers to be run in a MapReduce job?
A. The size of the input data
B. The number of nodes in the cluster
C. The data processing speed required
D. The configuration of the Hadoop cluster
Q.56 In which scenario would you configure multiple reducers in a MapReduce job?
A. When there is a need to process data faster
B. When the data is too large for a single reducer
C. When output needs to be partitioned across multiple files
D. All of the above
Q.57 What is the role of the Combiner function in a MapReduce job?
A. To manage the job execution
B. To reduce the amount of data transferred between the Map and Reduce tasks
C. To finalize the output data
D. To distribute tasks across nodes
Q.58 How does the MapReduce framework typically divide the processing of data?
A. Data is processed by key
B. Data is divided into rows
C. Data is split into blocks, which are processed in parallel
D. Data is processed serially
Q.59 Which operation is NOT a typical function of the Reduce phase in MapReduce?
A. Summation of values
B. Sorting the map output
C. Merging records with the same key
D. Filtering records based on a condition
Q.60 What action should you take if you notice that the HDFS capacity is unexpectedly decreasing?
A. Check for under-replicated blocks
B. Increase the block size
C. Decrease the replication factor
D. Add more DataNodes
Q.61 How does HBase handle scalability?
A. Through horizontal scaling by adding more nodes
B. Through vertical scaling by adding more hardware to existing nodes
C. By increasing the block size in HDFS
D. By partitioning data into more manageable pieces
Q.62 What is the primary storage model used by HBase?
A. Row-oriented
B. Column-oriented
C. Graph-based
D. Key-value pairs
Q.63 If a Pig script is unexpectedly slow, what should be checked first to improve performance?
A. The script’s logical plan.
B. The amount of data being processed.
C. The network latency.
D. The disk I/O operations.
Q.64 What is the first thing you should check if a Pig script fails due to an out-of-memory error?
A. The data sizes being processed.
B. The number of reducers.
C. The script’s syntax.
D. The JVM settings.
Q.65 How do you filter rows in Pig that match a specific condition?
A. FILTER data BY condition;
B. SELECT data WHERE condition;
C. EXTRACT data IF condition;
D. FIND data MATCHING condition;
Q.66 What Pig function aggregates data to find the total?
A. SUM(data.column);
B. TOTAL(data.column);
C. AGGREGATE(data.column, ‘total’);
D. ADD(data.column);
Q.67 How do you group data by a specific column in Pig?
A. GROUP data BY column;
B. COLLECT data BY column;
C. AGGREGATE data BY column;
D. CLUSTER data BY column;
Q.68 What Pig command is used to load data from a file?
A. LOAD ‘data.txt’ AS (line);
B. IMPORT ‘data.txt’;
C. OPEN ‘data.txt’;
D. READ ‘data.txt’;
Q.69 How can Pig scripts be optimized to handle large datasets more efficiently?
A. By increasing memory allocation for each task.
B. By using parallel processing directives.
C. By minimizing data read operations.
D. By rewriting scripts in Java.
Q.70 How does Pig handle schema-less data?
A. By inferring the schema at runtime.
B. By converting all inputs to strings.
C. By requiring manual schema definition before processing.
D. By rejecting schema-less data.
Q.71 In Pig, what is the difference between ‘STORE’ and ‘DUMP’?
A. ‘STORE’ writes the output to the filesystem, while ‘DUMP’ displays the output on the screen.
B. ‘STORE’ and ‘DUMP’ both write data to the filesystem but in different formats.
C. ‘DUMP’ writes data in compressed format, while ‘STORE’ does not compress data.
D. Both commands are used for debugging only.
Q.72 What makes Pig different from traditional SQL in processing data?
A. Pig processes data iteratively and allows multiple outputs from a single query.
B. Pig only allows batch processing.
C. Pig supports fewer data types.
D. Pig requires explicit data loading.
Q.73 What is Pig primarily used for in the Hadoop ecosystem?
A. Data transformations
B. Real-time analytics
C. Data encryption
D. Stream processing
Q.74 What should you check if a Hive job is running longer than expected without errors?
A. The complexity of the query
B. The configuration parameters for resource allocation
C. The data volume being processed
D. The network connectivity
Q.75 What is a common fix if a Hive query returns incorrect results?
A. Reboot the Hive server
B. Re-index the data
C. Check and correct the query logic
D. Increase the JVM memory for Hive
Q.76 How can you optimize a Hive query to limit the number of MapReduce jobs it generates?
A. Use multi-table inserts whenever possible
B. Reduce the number of output columns
C. Use fewer WHERE clauses
D. Increase the amount of memory allocated
Q.77 In Hive, which command would you use to change the data type of a column in a table?
A. ALTER TABLE table_name CHANGE COLUMN old_column new_column new_type
B. ALTER TABLE table_name MODIFY COLUMN old_column new_type
C. CHANGE TABLE table_name COLUMN old_column TO new_type
D. RETYPE TABLE table_name COLUMN old_column new_type
Q.78 How do you add a new column to an existing Hive table?
A. ALTER TABLE table_name ADD COLUMNS (new_column type)
B. UPDATE TABLE table_name SET new_column type
C. ADD COLUMN TO table_name (new_column type)
D. MODIFY TABLE table_name ADD (new_column type)
Q.79 What is the correct HiveQL command to list all tables in the database?
A. SHOW TABLES
B. LIST TABLES
C. DISPLAY TABLES
D. VIEW TABLES
Q.80 How does partitioning in Hive improve query performance?
A. By decreasing the size of data scans
B. By increasing data redundancy
C. By simplifying data complexities
D. By reducing network traffic
Q.81 Which Hive component is responsible for converting SQL queries into MapReduce jobs?
A. Hive Editor
B. Hive Compiler
C. Hive Driver
D. Hive Metastore
Q.82 What type of data models does Hive support?
A. Only structured data
B. Structured and unstructured data
C. Only unstructured data
D. Structured, unstructured, and semi-structured data
Q.83 How does Hive handle data storage?
A. It uses its own file system
B. It utilizes HDFS
C. It relies on external databases
D. It stores data in a proprietary format
Q.84 What is Hive mainly used for in the Hadoop ecosystem?
A. Data warehousing
B. Real-time processing
C. Data encryption
D. Stream processing
Q.85 If a Hive query runs significantly slower than expected, what should be checked first?
A. The structure of the tables and indexes
B. The configuration of the Hive server
C. The data size being processed
D. The network connectivity between Hive and HDFS
Q.86 What should you verify first if a Sqoop import fails?
A. The database connection settings
B. The format of the imported data
C. The version of Sqoop
D. The cluster status
Q.87 What functionality does the sqoop merge command provide?
A. Merging two Hadoop clusters
B. Merging results from different queries
C. Merging two datasets in HDFS
D. Merging updates from an RDBMS into an existing Hadoop dataset
Q.88 What is the primary command to view the status of a job in Oozie?
A. oozie job -info job_id
B. oozie -status job_id
C. oozie list job_id
D. oozie -jobinfo job_id
Q.89 How do you create a new table in Hive?
A. CREATE TABLE table_name (columns)
B. NEW TABLE table_name (columns)
C. CREATE HIVE table_name (columns)
D. INITIALIZE TABLE table_name (columns)
Q.90 Which command in HBase is used to scan all records from a specific table?
A. scan ‘table_name’
B. select * from ‘table_name’
C. get ‘table_name’, ‘row’
D. list ‘table_name’
Q.91 How does encryption at rest differ from encryption in transit within the context of Hadoop security?
A. Encryption at rest secures stored data, whereas encryption in transit secures data being transferred
B. Encryption at rest uses AES, while in transit uses TLS
C. Encryption at rest is optional, whereas in transit is mandatory
D. Encryption at rest is managed by HDFS, whereas in transit by YARN
Q. 92 What is the primary purpose of Kerberos in Hadoop security?
A. To encrypt data stored on HDFS
B. To manage user authentication and authorization
C. To audit data access
D. To ensure data integrity during transmission
Q.93 What should you do if the Hadoop cluster is running slowly after adding new nodes?
A. Check the configuration of new nodes
B. Rebalance the cluster
C. Increase the heap size of NameNode
D. All of these
Q.94 What common issue should be checked if a DataNode is not communicating with the NameNode?
A. Network issues
B. Disk failure
C. Incorrect NameNode address in configuration
D. All of these
Q.95 How do you manually rebalance the Hadoop filesystem to ensure even data distribution across the cluster?
A. hdfs balancer
B. hdfs dfs -rebalance
C. hdfs fsck -rebalance
D. hadoop dfs -balance
Q.96 What command is used to check the status of all nodes in a Hadoop cluster?
A. hdfs dfsadmin -report
B. yarn node -status
C. hadoop checknode -status
D. mapred liststatus
Q.97 How do you start all Hadoop daemons at once?
A. start-all.sh
B. start-dfs.sh && start-yarn.sh
C. run-all.sh
D. launch-hadoop.sh
Q.98 How can you ensure high availability of the NameNode in a Hadoop cluster?
A. By using a secondary NameNode
B. By configuring a standby NameNode
C. By increasing the memory of the NameNode
D. By replicating the NameNode data on all DataNodes
Q.99 Which configuration file in Hadoop is used to specify the replication factor for HDFS?
A. core-site.xml
B. hdfs-site.xml
C. mapred-site.xml
D. yarn-site.xml
Q.100 What role does the NameNode play in a Hadoop cluster?
A. It stores actual data blocks
B. It manages the file system namespace and controls access to files
C. It performs data processing
D. It manages resource allocation across the cluster
Q.101 What is the first step in setting up a Hadoop cluster?
A. Installing Hadoop on a single node
B. Configuring HDFS properties
C. Setting up the network configuration
D. Installing Java on all nodes
Q.102 When experiencing data inconsistency issues after a Flume event transfer, what should be checked first?
A. The configuration of source and sink channels
B. The network connectivity
C. The data serialization format
D. The agent configuration
Q.103 What should be the first check if a Sqoop import operation fails to start?
A. The database connection settings
B. The Hadoop cluster status
C. The syntax of the Sqoop command
D. The version of Sqoop
Q.104 What is the command to export data from HDFS to a relational database using Sqoop?
A. sqoop export –connect –table –export-dir
B. sqoop send –connect –table –export-dir
C. sqoop out –connect –table –export-dir
D. sqoop transfer –connect –table –export-dir
Q.105 How do you specify a target directory in HDFS when importing data using Sqoop?
A. –target-dir /path/to/dir
B. –output-dir /path/to/dir
C. –dest-dir /path/to/dir
D. –hdfs-dir /path/to/dir
Q.106 Which Sqoop command is used to import data from a relational database to HDFS?
A. sqoop import –connect –table
B. sqoop load –connect –table
C. sqoop fetch –connect –table
D. sqoop transfer –connect –table
Q.107 How do Sqoop and Flume complement each other in a big data ecosystem?
A. Sqoop handles batch data imports while Flume handles real-time data flow
B. Flume handles data imports while Sqoop handles data processing
C. Both are used for real-time processing
D. Both are used for batch data processing
Q.108 What kind of data can Flume collect and transport?
A. Only structured data
B. Only unstructured data
C. Both structured and unstructured data
D. Only semi-structured data
Q.109 What is the primary benefit of using Sqoop for data transfer between Hadoop and relational databases?
A. Minimizing the need for manual coding
B. Reducing the data transfer speed
C. Eliminating the need for a database
D. Maximizing data security
Q.110 How does Flume handle data flow from source to destination?
A. By using a direct connection method
B. By using a series of events and channels
C. By creating temporary storage in HDFS
D. By compressing data into batches
Q.111 What is Sqoop primarily used for?
A. Importing data from relational databases into Hadoop
B. Exporting data from Hadoop to relational databases
C. Real-time data processing
D. Stream processing
Q.112 When an HBase region server crashes, what recovery process should be checked to ensure it is functioning correctly?
A. The recovery of write-ahead logs
B. The rebalancing of the cluster
C. The replication of data to other nodes
D. The flushing of data from RAM to disk
Q. 113 What should be checked first if you encounter slow read speeds in HBase?
A. The configuration of the RegionServer
B. The health of Zookeeper nodes
C. The compaction settings of the table
D. The network configuration between clients and servers
Q.114 How can you create a snapshot of an HBase table for backup purposes?
A. SNAPSHOT ‘table_name’, ‘snapshot_name’
B. BACKUP TABLE ‘table_name’ AS ‘snapshot_name’
C. EXPORT ‘table_name’, ‘snapshot_name’
D. SAVE ‘table_name’ AS ‘snapshot_name’
Q.115 What HBase shell command is used to compact a table to improve performance by rewriting and merging smaller files?
A. COMPACT ‘table_name’
B. MERGE ‘table_name’
C. OPTIMIZE ‘table_name’
D. REDUCE ‘table_name’
Q.116 How do you increase the number of versions of cells stored in an HBase column family?
A. ALTER ‘table_name’, SET ‘column_family’, VERSIONS => number
B. SET ‘table_name’: ‘column_family’, VERSIONS => number
C. MODIFY ‘table_name’, ‘column_family’, SET VERSIONS => number
D. UPDATE ‘table_name’ SET ‘column_family’ VERSIONS = number
Q.117 What is the command to delete a column from an HBase table?
A. DELETE ‘table_name’, ‘column_name’
B. DROP COLUMN ‘column_name’ FROM ‘table_name’
C. ALTER ‘table_name’, DELETE ‘column_name’
D. ALTER TABLE ‘table_name’ DROP ‘column_name’
Q.118 In what way does HBase’s architecture differ from traditional relational databases when it comes to data modeling?
A. HBase does not support joins natively and relies on denormalized data models
B. HBase uses SQL for data manipulation
C. HBase structures data into tables, rows, and fixed columns
D. HBase requires data to be structured as cubes
Q.119 How does HBase perform read and write operations so quickly, particularly on large datasets?
A. By using RAM for initial storage of data
B. By employing advanced indexing techniques
C. By compressing data before storage
D. By using SSDs exclusively
Q.120 What mechanism does HBase use to ensure data availability and fault tolerance?
A. Data replication across multiple nodes
B. Writing data to multiple disk systems simultaneously
C. Automatic data backups
D. Checksum validations
Q.121 How do you optimize memory usage for MapReduce tasks to handle large datasets without running into memory issues?
A. Increase the Java heap space setting
B. Implement in-memory data management
C. Optimize data processing algorithms
D. Adjust task configuration
Q.122 How do you diagnose and resolve data skew in a Hadoop job that causes some reducers to take much longer than others?
A. Check and adjust the partitioner logic
B. Increase the number of reducers
C. Reconfigure the cluster to add more nodes
D. Manually redistribute the input data
Q.123 What should you check first if MapReduce jobs are taking longer than expected to write their output?
A. The configuration of the output format
B. The health of the HDFS nodes
C. The network conditions
D. The reducer phase settings
Q.124 How can you specifically control the distribution of data to reducers in a Hadoop job?
A. Specify mapreduce.job.reduces in the job’s configuration
B. Use a custom partitioner
C. Modify mapred-site.xml
D. Adjust reducer capacity
Q.125 How do you enable compression for MapReduce output in Hadoop?
A. Set mapreduce.output.fileoutputformat.compress to true in the job configuration
B. Set mapreduce.job.output.compression to true
C. Set hadoop.mapreduce.compress.map.output to true
D. Enable compression in core-site.xml
Q.126 What is the benefit of using compression in Hadoop data processing?
A. It increases the storage capacity on HDFS
B. It speeds up data transfer across the network by reducing the amount of data transferred
C. It simplifies data management
D. It enhances data security
Q.127 How does increasing the block size in HDFS affect performance?
A. It increases the overhead of managing metadata
B. It decreases the time to read data due to fewer seek operations
C. It increases the complexity of data replication
D. It decreases the efficiency of data processing
Q.128 What is the impact of data locality on Hadoop performance?
A. It increases data redundancy
B. It decreases job execution time
C. It increases network traffic
D. It decreases data availability
Q.129 What steps should be taken when a critical Hadoop daemon such as the NameNode or ResourceManager crashes?
A. Immediately restart the daemon
B. Analyze logs to determine the cause before restarting
C. Increase virtual memory settings
D. Contact support
Q.130 How do you identify and handle memory leaks in a Hadoop cluster?
A. By restarting nodes regularly
B. By monitoring garbage collection logs and Java heap usage
C. By increasing the memory allocation to Java processes
D. By reconfiguring Hadoop’s use of swap space
Q.131 What should you check first if a node in a Hadoop cluster is unexpectedly slow in processing tasks?
A. Network connectivity between the node and the rest of the cluster
B. Disk health of the node
C. CPU utilization rates of the node
D. Configuration settings of Hadoop on the node
Q.132 How can you configure the logging level of a running Hadoop daemon without restarting it?
A. By modifying the log4j.properties file and reloading it via the command line
B. By using the hadoop log -setlevel command with the appropriate daemon and level
C. By editing the hadoop-env.sh file
D. By updating the Hadoop configuration XMLs and performing a rolling restart
Q.133 What command is used to view the current status of all nodes in a Hadoop cluster?
A. hdfs dfsadmin -report
B. hadoop fs -status
C. yarn node -list
D. mapred listnodes
Q.134 What role does log aggregation play in Hadoop troubleshooting?
A. It decreases the volume of logs for faster processing
B. It centralizes logs for easier access and analysis
C. It encrypts logs for security
D. It filters out unnecessary log information
Q.135 How do resource managers contribute to the troubleshooting process in a Hadoop cluster?
A. They allocate resources optimally to prevent job failures
B. They provide logs for failed jobs
C. They reroute traffic during node failures
D. They automatically correct configuration errors
Q.136 What is the primary tool used for monitoring Hadoop cluster performance?
A. Ganglia
B. Nagios
C. Ambari
D. HDFS Audit Logger
Q.137 What is a crucial step in troubleshooting a slow-running MapReduce job in Hadoop?
A. Check the configuration of task trackers
B. Examine the job’s code for inefficiencies
C. Monitor network traffic
D. Review data input sizes and formats
Q.138 What should you check if a node repeatedly fails in a Hadoop cluster?
A. Node hardware issues
B. HDFS permissions
C. The validity of data blocks
D. The JobTracker status
Q.139 What command is used to rebalance the Hadoop cluster to ensure even distribution of data across all nodes?
A. hadoop balancer
B. dfsadmin -rebalance
C. hdfs dfs -rebalance
D. hadoop fs -balance
Q.140 How do you manually start the Hadoop daemons on a specific node?
A. start-daemon.sh
B. hadoop-daemon.sh start
C. start-node.sh
D. node-start.sh
Q.141 How can administrators optimize a Hadoop cluster’s performance during high data load periods?
A. By increasing the memory of each node
B. By adding more nodes to the cluster
C. By prioritizing high-load jobs
D. By reconfiguring network settings
Q.142 What is the impact of a poorly configured Hadoop cluster on data processing?
A. Increased processing speed
B. Decreased data security
C. Irregular data processing times
D. Reduced resource utilization
Q.143 How does Hadoop handle hardware failures to maintain data availability?
A. By immediately replicating data to other data centers
B. By using RAID configurations
C. By replicating data blocks across multiple nodes
D. By storing multiple copies of data in the same node
Q.144 What is the main purpose of the Hadoop JobTracker?
A. To store data on HDFS
B. To manage resources across the cluster
C. To track the execution of MapReduce tasks
D. To coordinate data replication
Q.145 How do you resolve issues related to data encryption keys not being accessible in Hadoop?
A. Reconfigure the key management service settings
B. Restart the Hadoop cluster
C. Update the encryption policies
D. Generate new encryption keys
Q.146 What is the first step to troubleshoot if you cannot authenticate with a Hadoop cluster using Kerberos?
A. Verify the Kerberos server status
B. Check the network connectivity
C. Review the Hadoop and Kerberos configuration files
D. Check the system time settings on your machine
Q.147 How can you configure Hadoop to use a custom encryption algorithm for data at rest?
A. Define the custom algorithm in the hdfs-site.xml under the dfs.encrypt.data.transfer.algorithm property
B. Update hdfs-site.xml with dfs.encryption.key.provider.uri set to your key provider
C. Modify core-site.xml with hadoop.security.encryption.algorithm set to your algorithm
D. Adjust hdfs-site.xml with dfs.data.encryption.algorithm set to your algorithm
Q.148 How do you enable HTTPS for a Hadoop cluster to secure data in transit?
A. Set dfs.http.policy to HTTPS_ONLY in hdfs-site.xml
B. Change hadoop.ssl.enabled to true in core-site.xml
C. Update hadoop.security.authentication to ssl
D. Modify the dfs.datanode.https.address property
Q.149 What is the primary security challenge that Hadoop faces due to its distributed computing model?
A. Coordination between different data nodes
B. Protection of data integrity across multiple systems
C. Ensuring consistent network performance
D. Managing varying data formats
Q.150 What role does Apache Ranger play in Hadoop security?
A. It provides a framework for encryption
B. It is primarily used for data auditing
C. It manages detailed access control policies
D. It is used for network traffic monitoring
