📚 AKTU · B.Tech Sem VI · BCS061 / KCS061

Big Data Exam Prep
Guide 2025

Complete PYQ analysis · sure-shot questions · unit-wise diagrams · model answers · 3-day strategy — all in one place.

2PYQs Analysed
5Units
24+Sure-Shot Qs
5Diagrams
70Max Marks

Overview

PYQ Analysis & Exam Strategy

Deep analysis of AKTU 2023-24 (KCS061, 100 marks) and 2024-25 (BCS061, 70 marks) papers — repeated topics, weightage, and scoring strategy.

2
PYQs
5
Units
24+
Sure-Shot Qs
5
Key Diagrams
70
Max Marks
⚠️
Paper changed in 2024-25: now 70 marks (was 100). Section C = 7 marks each (was 10). Write concisely and always include diagrams.
✅
Paper pattern: Section A = all 7 short 2-mark Qs, Section B = attempt 3 of 5 (7 marks each), Section C = attempt 1 of 2 per question (7 marks each, 5 questions).
💡
New in 2024-25: Master-Slave vs Peer-Peer Replication, Spark components, and detailed Pig comparisons appeared for the first time. Prepare as bonus topics.

Most Repeated Topics — Frequency Table

Topic2023-242024-25Priority
5 Vs of Big Data✅ 10 marks✅ 7 marks🔥 MUST DO
HDFS Architecture✅ 10+10 marks✅ 7 marks🔥 MUST DO
MapReduce Architecture✅ 10 marks✅ 7 marks🔥 MUST DO
Hadoop Ecosystem Components✅ 10 marks✅ Asked Twice🔥 MUST DO
YARN Architecture✅ 2 marks✅ 7 marks🔥 MUST DO
Apache Hive Architecture✅ 10 marks✅ 7 marks🔥 MUST DO
Hadoop in Cloud (AWS/Azure/GCP)✅ 10 marks✅ 7 marks🔥 MUST DO
Analysis vs Reporting✅ 10 marks✅ 7 marks⭐ Very Imp
Spark / RDDs✅ 10 marks✅ 7 marks⭐ Very Imp
Apache Pig / Pig Latin✅ 2+2 marks✅ 7 marks⭐ Very Imp
NoSQL Databases✅ 10 marks—Medium
MongoDB CRUD✅ 10 marks—Medium
HBase Architecture✅ 10 marks—Medium
Master-Slave / Peer-Peer Replication—✅ 7 marks🆕 New 2025
Types of Analytics—✅ 7 marks🆕 New 2025

Unit-wise Weightage & Priority

Unit 1 Big Data Introduction
Weight: 20–25% · Priority: High
5 Vs, Analytics types, Analysis vs Reporting
Unit 2 Hadoop & MapReduce
Weight: 25–30% · Priority: Highest
Ecosystem, MapReduce phases, Streaming
Unit 3 HDFS & Hadoop Env
Weight: 20–25% · Priority: High
HDFS Read/Write, NameNode/DataNode, Cloud
Unit 4 YARN, NoSQL, Spark
Weight: 20–25% · Priority: High
YARN Architecture, RDDs, MongoDB CRUD
Unit 5 Pig, Hive, HBase
Weight: 15–20% · Priority: High
Hive Architecture, Pig vs Hive, HBase

AKTU Paper Pattern (2024-25)

SectionQuestionsMarksTotalStrategy
Section AAttempt ALL 7 short Qs2 each14Definition + 2 bullet points. Do this first — easy 14 marks.
Section BAttempt any 3 of 57 each21Pick your strongest 3 topics. Always draw a diagram.
Section C (Q3–Q7)Attempt 1 of 2 per question7 each35One topic per question pair. Diagrams are mandatory here.
Total70—

Unit 1 · 6 Hours

Introduction to Big Data

The 5 Vs and Analysis vs Reporting are guaranteed questions — both appeared in both PYQs (7–10 marks each).

🔥
5 Vs of Big Data appeared in BOTH years — 10 marks in 2023-24 and 7 marks in 2024-25. The single highest-probability question in the entire Big Data paper. Know it cold.

Core Topics

🔥 5 Vs of Big Data Both Years
Volume, Velocity, Variety, Veracity, Value. Appears as Section A (2-mark), Section B, and Section C. The most repeated Big Data topic in AKTU history.
⭐ Analysis vs Reporting Both Years
Advanced analytics uncovers hidden patterns (predictive); reporting summarises known data (descriptive). 7–10 mark question in both papers.
Types of Digital Data Short 2-mark
Structured: SQL tables, Excel sheets.
Semi-structured: JSON, XML, CSV.
Unstructured: Images, videos, emails, social media posts.
Big Data Platforms Short 2-mark
Hadoop, Apache Spark, Apache Kafka, Apache Flink, Google BigQuery, Amazon Redshift, Apache Storm, Azure HDInsight.

5 Vs — Complete Revision Table

VNameMeaningReal-World Example
V₁VolumeMassive quantity of data generated every secondFacebook: 500TB/day; YouTube: 500 hrs video/min uploaded
V₂VelocitySpeed at which data is generated and must be processedTwitter: 6,000 tweets/sec; Stock exchange: microsecond feeds
V₃VarietyMultiple data types and formats from diverse sourcesText, images, video, audio, sensor data, log files
V₄VeracityQuality, accuracy and trustworthiness of dataNoisy IoT sensors; duplicate records; fake social media accounts
V₅ValueActionable business insight extracted after processingNetflix recommendations; Amazon product suggestions; fraud detection
🧠 Memory Trick: "Very Vast Varieties Verify Value" → V · V · V · V · V

Analysis vs Reporting — Comparison Table

FeatureData AnalysisReporting
PurposeDiscover hidden patterns & insightsSummarise and present known facts
ApproachExploratory, hypothesis-drivenDescriptive, structured, periodic
OutputActionable insights, predictions, modelsCharts, tables, dashboards, KPIs
TechniquesML, statistical modelling, data miningSQL queries, pivot tables, aggregation
UsersData scientists, ML engineersBusiness managers, executives
Example QuestionWhy are customers churning?How many customers left this month?

4 Types of Big Data Analytics New 2024-25

📊 Descriptive Analytics
Answers: What happened?
Summarises historical data. Example: Monthly sales report, website traffic dashboard, page view counts.
🔍 Diagnostic Analytics
Answers: Why did it happen?
Identifies root causes through drill-down. Example: Why did Q3 sales drop? Root cause analysis.
🔮 Predictive Analytics
Answers: What will happen?
Uses ML and statistical models. Example: Customer churn prediction, demand forecasting, weather prediction.
⚙️ Prescriptive Analytics
Answers: What should we do?
Recommends actions and decisions. Example: Optimal pricing engine, supply chain optimisation, route planning.

📌 Unit 1 — Quick Revision & 5 Vs Diagram

5 Vs Pentagon — Draw This in Exam for Extra Marks

BIG DATA V1 Volume Huge scale V2 Velocity High speed V3 Variety Many types V4 Veracity Data quality V5 Value Insights

Fig 1.1 — 5 Vs of Big Data (Pentagon Model) — Label each circle with name + brief meaning

🔴 Must-Know Definitions

  • Volume: Scale of data (PB, EB level)
  • Velocity: Speed of data generation & processing
  • Variety: Structured / semi / unstructured types
  • Veracity: Data quality & accuracy
  • Value: Business insights extracted from data

⭐ Expected 2-Mark Answers

  • List 5 Big Data platforms
  • Structured vs Unstructured data examples
  • What is Big Data? (definition)
  • What is data analytics?
  • What is Veracity in Big Data?

🏆 High-Mark Focus Topics

  • 5 Vs full explanation with diagram (7–10 marks)
  • Analysis vs Reporting comparison table (7–10 marks)
  • Real-world Big Data applications
  • 4 types of Big Data analytics

Unit 1 — Expected Questions

[Q1 SURE SHOT] Describe the 5 Vs of Big Data. What does each represent and why are they essential for data management? Repeated Both Years
[Q2 VERY IMP] Distinguish between data analysis and reporting in Big Data. How does advanced analytics uncover hidden patterns beyond traditional reporting? Both Years
[Q3] Discuss the various types of analytics used in Big Data (Descriptive, Diagnostic, Predictive, Prescriptive). New 2024-25
[Q4] Provide real-world Big Data examples in healthcare, finance, e-commerce, and transportation industries.
[Short 2-mark] What are structured, semi-structured, and unstructured data? Give examples of each.
[Short 2-mark] List any five Big Data platforms.

Unit 2 · 8 Hours

Hadoop & MapReduce

Highest-weightage unit. Hadoop ecosystem components and MapReduce architecture appear in every AKTU paper. "Hadoop ecosystem" was asked twice in 2024-25.

🔥
"Hadoop Ecosystem Components" appeared TWICE in the 2024-25 paper (Q1e and Q4b). Prepare a complete 11-component table and reproduce it from memory.

Hadoop Ecosystem — All 11 Components

ComponentCategoryPurpose
HDFSStorageDistributed file system — stores data reliably across cluster nodes in 128 MB blocks
MapReduceProcessingDistributed batch processing framework (Map → Shuffle → Reduce)
YARNResource MgmtManages CPU/RAM; schedules and monitors all jobs on the cluster
HiveQuerySQL-like querying (HiveQL) on Hadoop — used by data analysts
PigScriptingHigh-level ETL scripting using Pig Latin; translates to MapReduce jobs
HBaseDatabaseColumn-oriented NoSQL database on top of HDFS — random read/write
ZooKeeperCoordinationDistributed coordination and synchronisation service for the cluster
SqoopIngestionTransfers structured data between RDBMS ↔ Hadoop (bulk import/export)
FlumeIngestionCollects and moves streaming/log data into HDFS in real time
SparkProcessingFast in-memory processing engine — up to 100× faster than MapReduce
OozieWorkflowJob scheduling and workflow coordination for Hadoop job pipelines

MapReduce — Step by Step

1
Input Splits: Input data in HDFS is divided into fixed-size chunks (default 128 MB). Each split is processed in parallel by a separate Mapper task.
2
Map Phase: Mapper processes each record. Input: (key, value) pairs. Output: intermediate (key, value) pairs. Example: word → (word, 1).
3
Combiner (Optional): Mini-reducer running locally on each mapper node. Reduces network traffic before shuffle. Acts as local pre-aggregation.
4
Shuffle & Sort: Framework sorts all intermediate pairs by key and transfers to the appropriate Reducer. Same key always goes to same Reducer.
5
Reduce Phase: Reducer aggregates all values for a given key into a single output value. Example: (word,[1,1,1]) → (word,3).
6
Output to HDFS: Each Reducer writes one output file to HDFS. Client reads the final results from these files.
Classic Word Count Example
Input: "Big Data is Big and Big Data is Fast"
-- Map Phase --
(Big,1) (Data,1) (is,1) (Big,1) (and,1) (Big,1) (Data,1) (is,1) (Fast,1)

-- After Shuffle & Sort (grouped by key) --
(Big,[1,1,1]) (Data,[1,1]) (Fast,[1]) (and,[1]) (is,[1,1])

-- Reduce Output --
(Big,3) (Data,2) (Fast,1) (and,1) (is,2)

Hadoop Streaming — Short Note

Hadoop Streaming is a utility that allows developers to write MapReduce programs in any language that can read from stdin and write to stdout — Python, Ruby, Perl, or bash scripts.

The Streaming API creates Map and Reduce tasks as standard processes, then pipes data in/out via stdin/stdout.

Key Advantage: No need to write Java. Data scientists can use Python directly to write MapReduce jobs.
Usage: hadoop jar streaming.jar -mapper mapper.py -reducer reducer.py -input /data -output /result

📌 Unit 2 — Quick Revision & MapReduce Diagram

MapReduce Architecture — Draw This in Exam

INPUT Data HDFS Split 1 Split 2 Split 3 Mapper 1 Mapper 2 Mapper 3 SHUFFLE & SORT Reducer 1 Reducer 2 OUTPUT HDFS ① Input ② Splits ③ Map ④ Shuffle & Sort ⑤ Reduce ⑥ Output

Fig 2.1 — MapReduce Architecture (Input → Splits → Map → Shuffle & Sort → Reduce → Output to HDFS)

🔴 Key Facts to Memorise

  • Default split size = 128 MB
  • JobTracker manages jobs (Hadoop 1.x)
  • TaskTracker runs tasks on each node
  • YARN replaces JobTracker in Hadoop 2.x
  • Combiner is optional — acts as local Reducer

⚠️ Common Exam Mistakes

  • MapReduce is a processing framework — NOT a database
  • Combiner is not always present in MapReduce
  • Same key always goes to the same Reducer (after shuffle)
  • Shuffle & Sort is done by the framework, not the developer

Unit 2 — Expected Questions

[Q1 SURE SHOT] Explain Apache Hadoop and its role in Big Data processing. What are the core components of the Hadoop ecosystem and how do they work together? Both Years — asked twice in 2024-25
[Q2 SURE SHOT] Discuss the detailed architecture of MapReduce — Map phase, Shuffle & Sort, Reduce phase — with a diagram. Both Years
[Q3 VERY IMP] Discuss the process of developing a MapReduce application. What are the key steps in writing, testing, and deploying?
[Short 2-mark] What is Hadoop Streaming?
[Short 2-mark] Discuss data formats commonly used in Hadoop (SequenceFile, Avro, Parquet, ORC, Text).
[Short 2-mark] How does Apache Hadoop help process data?

Unit 3 · 8 Hours

HDFS & Hadoop Environment

HDFS architecture and read/write operations appear in every paper. Cloud deployment appeared in both PYQs. The NameNode vs Secondary NameNode distinction is a very common trap.

⚠️
Most common exam trap: Secondary NameNode is NOT a backup of NameNode! It only periodically checkpoints metadata (merges fsimage + edit logs). If you write this incorrectly, marks will be deducted.

HDFS Architecture — All Components

🗄️ NameNode (Master)
• Stores all metadata (file names, block locations, permissions, directory structure)
• Does NOT store actual file data — only the directory tree
• Single point of failure → solved by HA NameNode in Hadoop 2.x
• Maintains fsimage (filesystem snapshot) and edit logs (change transactions)
• Runs on the master node of the cluster
💾 DataNode (Slave)
• Stores actual data blocks on local disk
• Sends heartbeat to NameNode every 3 seconds (proof of life)
• Sends block report to NameNode every 6 hours
• Handles read/write requests directly from clients
• Reports full block list to NameNode on startup
🔄 Secondary NameNode
• NOT a backup — it is a checkpoint node only
• Periodically merges fsimage + edit logs (checkpointing process)
• Reduces NameNode restart time after failure
• Runs on a separate machine from primary NameNode
📦 Block Replication
• Default block size = 128 MB
• Default replication factor = 3 (configurable)
• Rack-aware placement: 2 replicas on same rack, 1 on different rack
• If a DataNode fails, data is still available from other replicas

HDFS Read Operation (5 Steps)

1
Client → NameNode: Client opens the file by calling open() on DistributedFileSystem with the file path.
2
NameNode Response: NameNode returns block locations — IP addresses of DataNodes containing each block, sorted by proximity to the client.
3
Client → Nearest DataNode: Client connects to the closest DataNode using FSDataInputStream and reads the first block.
4
Checksum Verification: Client verifies data integrity using checksums stored with each block. If corrupted, reads from next replica automatically.
5
Repeat & Assemble: Client reads all blocks sequentially. If a DataNode fails mid-read, moves to the next replica. All blocks assembled to reconstruct the complete file.

HDFS Write Operation (7 Steps)

1
Client → NameNode: Client calls create() on DistributedFileSystem. NameNode checks permissions and ensures the file doesn't already exist.
2
DataNode Assignment: NameNode selects 3 DataNodes using rack-aware algorithm and returns their addresses to the client.
3
Pipeline Setup: DataNodes form a replication pipeline: Client → DataNode₁ → DataNode₂ → DataNode₃.
4
Data Packets: Client breaks data into packets and writes to DataNode₁ through FSDataOutputStream.
5
Replication: DataNode₁ replicates to DataNode₂; DataNode₂ replicates to DataNode₃ — simultaneously down the pipeline.
6
Acknowledgments: Each DataNode sends an ACK back up the pipeline to the client confirming successful receipt of the packet.
7
Close & Notify NameNode: Client closes the file. NameNode updates metadata with final block locations and marks the file as complete.

Hadoop in Cloud — Appeared Both Years

✅ Advantages
• No upfront hardware cost (pay-as-you-go)
• Auto-scaling based on workload demand
• Managed services reduce administration overhead
• Global availability & built-in disaster recovery
• Integration with native cloud storage (S3, Blob, GCS)
⚠️ Challenges
• Data transfer latency and bandwidth costs
• Security and compliance concerns (data sovereignty)
• Vendor lock-in risk when using proprietary features
• Unpredictable billing for variable workloads
• Network dependency for distributed computation
Cloud ProviderManaged Hadoop ServiceCloud Storage
Amazon Web ServicesAmazon EMR (Elastic MapReduce)Amazon S3
Microsoft AzureAzure HDInsightAzure Blob Storage
Google Cloud PlatformGoogle Cloud DataprocGoogle Cloud Storage

📌 Unit 3 — Quick Revision & HDFS Architecture Diagram

HDFS Architecture — Most Important Diagram in the Entire Course

CLIENT Application NAMENODE Stores Metadata Only fsimage + edit logs (Master Node) SECONDARY NAMENODE Checkpoint only ⚠️ NOT a backup! DATANODE 1 Block A · Block B Rack 1 DATANODE 2 Block A · Block C Rack 1 DATANODE 3 Block B · Block C Rack 2 1. Metadata request 2. Block locations 3. R/W Checkpoint Client request NameNode response Heartbeat / Block report Checkpoint (Secondary NN)

Fig 3.1 — HDFS Architecture (Client, NameNode, Secondary NameNode, 3 DataNodes with Rack Awareness)

🔴 Critical Facts

  • Block size = 128 MB (default)
  • Replication factor = 3 (default)
  • Secondary NameNode = Checkpoint only — NOT backup
  • DataNode heartbeat = every 3 seconds
  • DataNode declared dead if no heartbeat for 10 minutes

☁️ Cloud Platforms (Both Years!)

  • AWS → Amazon EMR
  • Azure → Azure HDInsight
  • GCP → Cloud Dataproc
  • Key advantage: Auto-scaling
  • Key challenge: Data transfer latency

Unit 3 — Expected Questions

[Q1 SURE SHOT] Explain HDFS — NameNode, DataNode, file system namespace. How does HDFS manage storage and replication across a distributed cluster? Both Years
[Q2 SURE SHOT] Explain how HDFS stores, reads, and writes files. Describe the complete sequence of operations for each process. Both Years
[Q3 VERY IMP] Discuss advantages and challenges of deploying Hadoop in cloud (AWS EMR / Azure HDInsight / GCP Dataproc). Both Years
[Q4] Discuss cluster specification. Describe how to set up a Hadoop Cluster step by step. New 2024-25
[Short 2-mark] What is HDFS in the context of Hadoop?
[Short 2-mark] What are block sizes and block abstraction in HDFS?
[Short 2-mark] What are the benefits and challenges of HDFS for distributed storage?

Unit 4 · 9 Hours

YARN, NoSQL, Spark & MongoDB

YARN architecture and Spark RDDs appeared in both PYQs. NoSQL and MongoDB are common Section B choices. Scala is low-priority for AKTU.

YARN Architecture — All 4 Components

ComponentRuns WhereDetailed Role
ResourceManager1 per cluster (master node)Global resource allocator. Two sub-components: Scheduler (allocates resources to apps) and ApplicationsManager (accepts job submissions, restarts failed AppMasters).
NodeManagerEvery worker nodePer-node agent. Monitors CPU/RAM usage on that node, manages containers, reports resource availability to ResourceManager, kills containers as instructed.
ApplicationMaster1 per application (worker node)Per-application coordinator. Negotiates resources with ResourceManager, works with NodeManager to execute tasks, monitors task progress, handles task failures.
ContainerWorker nodesBasic unit of resource allocation (specific CPU + RAM amount). All actual computation tasks (Mappers, Reducers, Spark executors) run inside containers.
💡
Why YARN matters: In Hadoop 1.x, MapReduce handled BOTH resource management AND processing — limiting the cluster to MapReduce only. YARN separates these, allowing Spark, Hive, Pig, and more to share the same cluster (multi-tenancy).

YARN Schedulers Short 2-mark

⚖️ Fair Scheduler
Resources shared equally among all running applications. Short jobs finish quickly. Good for mixed small/large workloads. Default in CDH (Cloudera).
📊 Capacity Scheduler
Cluster resources divided into queues with guaranteed capacity per team/department. Unused capacity shared with others. Default in Apache Hadoop (HDP).

Apache Spark & RDDs

What is an RDD?
Resilient = Fault-tolerant (recomputes lost partitions from lineage)
Distributed = Data spread across cluster nodes in partitions
Dataset = Immutable collection of elements processed in parallel
Why Spark is 100× faster?
MapReduce reads/writes to disk after every step (slow I/O).
Spark stores intermediate results in RAM between steps.
Critical for iterative ML algorithms that run 100+ passes over data.
Operation TypeExamplesWhen Executed?Returns
Transformations (Lazy)map(), filter(), flatMap(), groupByKey(), reduceByKey()NOT immediately — only when an action is calledNew RDD
Actions (Eager)count(), collect(), reduce(), saveAsTextFile(), first()Immediately triggers full computation on the clusterValue or side-effect

NoSQL Database Types

TypeStorage ModelExamplesBest Use Case
Key-ValueSimple key → value pairsRedis, DynamoDB, RiakCaching, session storage, shopping carts
DocumentJSON / BSON documentsMongoDB, CouchDB, FirestoreCatalogs, user profiles, content management
Column-FamilyRows + column families (wide columns)HBase, Cassandra, BigtableTime-series, IoT sensor data, analytics
GraphNodes + Edges + PropertiesNeo4j, Amazon NeptuneSocial networks, fraud detection, recommendations

MongoDB CRUD Operations

OperationCommandExample Syntax
CreateinsertOne() / insertMany()db.students.insertOne({name:"Raj", marks:85, dept:"CS"})
Readfind() / findOne()db.students.find({marks:{$gt:80}})
UpdateupdateOne() / updateMany()db.students.updateOne({name:"Raj"},{$set:{marks:90}})
DeletedeleteOne() / deleteMany()db.students.deleteOne({name:"Raj"})

📌 Unit 4 — Quick Revision & YARN Diagram

YARN Architecture — Draw This in Exam

CLIENT Submits Job RESOURCE MANAGER Scheduler + AppManager Global Resource Allocation WORKER NODE 1 NodeManager App Master Container 1 · Container 2 WORKER NODE 2 NodeManager Container Container 3 · Container 4 WORKER NODE 3 NodeManager Submit job Allocate Containers

Fig 4.1 — YARN Architecture (Client → ResourceManager → NodeManagers → Containers)

⚡ RDD Quick Facts

  • RDD = Resilient Distributed Dataset
  • Transformations are lazy — deferred until action
  • Actions are eager — trigger computation
  • Spark uses DAG (Directed Acyclic Graph) for execution planning
  • RDD lineage allows recomputation of lost partitions

🗄️ NoSQL vs RDBMS

  • NoSQL = schema-less; RDBMS = fixed schema
  • NoSQL = horizontal scaling; RDBMS = vertical
  • NoSQL = BASE model; RDBMS = ACID
  • 4 types: Key-Value, Document, Column-Family, Graph

Unit 4 — Expected Questions

[Q1 SURE SHOT] Discuss the detailed architecture of YARN — ResourceManager, NodeManager, ApplicationMaster, Container — with diagram. Both Years
[Q2 SURE SHOT] What are RDDs in Spark? How do they enable fault-tolerant distributed data processing? Both Years
[Q3 VERY IMP] Define NoSQL databases. What are the key characteristics and benefits compared to traditional relational databases?
[Q4 VERY IMP] Explain MongoDB CRUD operations with syntax and examples for each (insertOne, find, updateOne, deleteOne).
[Q5] Explain the features and components of Apache Spark (Core, SQL, Streaming, MLlib, GraphX). New 2024-25
[Short 2-mark] What are the characteristics of Fair Scheduler and Capacity Scheduler?
[Short 2-mark] What is the role of YARN in Hadoop?

Unit 5 · 9 Hours

Pig, Hive & HBase

Hive architecture appeared in both PYQs. 2024-25 introduced a direct three-way Pig comparison. Know Pig vs Hive vs MapReduce differences clearly with a table.

Apache Hive Architecture — Data Flow (7 Steps)

1
User writes HiveQL: SQL-like query written by data analyst. Example: SELECT dept, COUNT(*) FROM employees GROUP BY dept;
2
Driver: Receives the HiveQL query and manages its complete lifecycle — parsing, planning, execution, result delivery.
3
Compiler: Parses HiveQL → checks syntax → generates Abstract Syntax Tree (AST) → creates logical execution plan.
4
Metastore: Contains all table schemas, column types, partition info, and data locations in HDFS. Compiler fetches schema from here during planning.
5
Optimizer: Optimises the execution plan — partition pruning, predicate pushdown, join reordering — to minimise data read and shuffle.
6
Execution Engine: Converts the optimised plan into MapReduce / Tez / Spark jobs and submits them to YARN for execution on the cluster.
7
HDFS & Results: Jobs execute on the cluster. Data read from HDFS, processed, and results returned to the user via Hive CLI, Beeline, or JDBC/ODBC.

Pig vs Hive vs MapReduce vs SQL — Master Comparison Direct 2024-25 Question

FeatureApache PigApache HiveMapReduceSQL (RDBMS)
LanguagePig LatinHiveQL (SQL-like)Java APIStandard SQL
Target UsersETL developers, data engineersData analysts, SQL usersJava developersSQL developers, DBAs
SchemaOptional (flexible, schema-on-read)Required (strict, schema-on-read)None — raw dataRequired (schema-on-write)
Data StructuresBags, Tuples, MapsTables, Rows, ColumnsKey-value pairsTables, Rows, Columns
Ease of UseMedium (scripting language)Easy (familiar SQL syntax)Hard (verbose Java code)Easy (declarative SQL)
Data ExplorationGoodExcellentPoor (very tedious)Limited to DB size
Translates toMapReduce jobsMapReduce / Tez / SparkDirect executionQuery engine (InnoDB etc.)
Best forETL pipelines, data transformationAd-hoc queries, BI reportsCustom batch processingOLTP, transactional systems
Data ScalePetabyte-scale (HDFS)Petabyte-scale (HDFS)Petabyte-scaleGigabyte scale (single server)

HBase Architecture

🏛️ HMaster
• Master node of HBase cluster
• Manages and monitors RegionServers
• Handles DDL operations (create, delete, alter tables)
• Performs load balancing across RegionServers
• Assigns Regions to RegionServers on startup/failure
⚙️ RegionServer
• Handles read and write operations for data regions
• A Region = contiguous range of rows sorted by row key
• Each RegionServer manages multiple Regions
• Communicates with HDFS DataNodes for actual data storage
FeatureHBaseTraditional RDBMS
Data ModelColumn-family (wide, sparse tables)Row-based (normalized, dense tables)
SchemaSchema-less columns (highly flexible)Fixed schema (ALTER TABLE needed to add columns)
ScalabilityHorizontal (add more commodity nodes)Vertical (upgrade server hardware — expensive)
TransactionsSingle-row ACID onlyFull multi-row, multi-table ACID transactions
Query LanguageJava API / HBase Shell / REST APIStandard SQL with full JOIN support
Best forBillions of rows, random real-time accessComplex queries, reporting, foreign keys
Real ExamplesFacebook Messages, Twitter timelines, IoT dataBanking systems, e-commerce orders, inventory

📌 Unit 5 — Quick Revision & Hive Architecture Diagram

Apache Hive Data Flow — Draw This in Exam

USER HiveQL DRIVER Lifecycle Mgmt COMPILER Parse + Plan METASTORE Schema + Table Info OPTIM- IZER Best Plan EXECUTOR MR / Tez / Spark HDFS Data + Results RESULT to User ① Query ② Driver ③ Compile ④ Optimise ⑤ Execute ⑥ HDFS ⑦ Result

Fig 5.1 — Hive Architecture & Data Flow (HiveQL → Driver → Compiler ↔ Metastore → Optimizer → Executor → HDFS → Result)

🐷 Pig Key Facts

  • Language = Pig Latin
  • Interactive shell = Grunt
  • Execution modes: Local, MapReduce, Tez
  • Main ops: LOAD, FILTER, FOREACH, GROUP, JOIN, STORE
  • Good for: ETL pipelines, data transformation at scale

🏛️ HBase Key Facts

  • Column-family NoSQL DB built on HDFS
  • Master = HMaster
  • Workers = RegionServers
  • Good for: billions of rows, random real-time access
  • Examples: Facebook Messages, Twitter timelines

🐝 Hive Key Facts

  • Language = HiveQL (SQL-like)
  • Schema info stored in Metastore
  • Translates to MapReduce / Tez / Spark
  • Best for: ad-hoc SQL queries on large HDFS datasets
  • Not good for: real-time queries (batch only)

Unit 5 — Expected Questions

[Q1 SURE SHOT] Provide an overview of Apache Hive architecture. How does Hive translate HiveQL queries into MapReduce jobs? Include data flow diagram. Both Years
[Q2 SURE SHOT] Compare and contrast: (i) Apache Pig vs MapReduce (ii) Pig vs SQL (iii) Pig vs Hive. 2024-25 direct question
[Q3 VERY IMP] Explain HBase — how it differs from relational databases and what advantages it offers for large-scale data storage and access.
[Q4 VERY IMP] Explain the role of Pig Latin as a high-level scripting language for processing large datasets. How does it simplify data transformation compared to MapReduce?
[Short 2-mark] What is Apache Pig?
[Short 2-mark] Describe the Grunt shell in Apache Pig.
[Short 2-mark] How does Hive differ from Pig in the Hadoop ecosystem?

Sure-Shot Questions

Top 24 Questions by Probability

Ranked by AKTU frequency, marks value, and trend analysis across PYQs 2023-24 and 2024-25.

🔥
TIER 1 — Appeared in BOTH papers. Prepare all 9 with complete diagrams and keyword-rich answers. Knowing even 5 of these well = 35–50+ marks.
01 Describe the 5 Vs of Big Data — Volume, Velocity, Variety, Veracity, Value — with examples. Why are they essential for data management and analysis? Both Years · 7–10 marks
02 Explain HDFS — NameNode, DataNode, file system namespace. How does HDFS manage data storage and replication across a distributed cluster? Both Years · 7–10 marks
03 Explain how HDFS stores, reads, and writes files. Describe the complete sequence of operations for each process. Both Years · 7–10 marks
04 Discuss the detailed architecture of MapReduce — Map phase, Shuffle & Sort, Reduce phase — with a clearly labelled diagram. Both Years · 7–10 marks
05 Explain Apache Hadoop and its role in Big Data processing. What are the core components of the Hadoop ecosystem and how do they work together? Both Years — asked twice in 2024-25 · 7–10 marks
06 Discuss the detailed architecture of YARN — ResourceManager, NodeManager, ApplicationMaster, Container — with a diagram. Both Years · 7–10 marks
07 Provide an overview of Apache Hive architecture. How does HiveQL translate SQL-like queries into MapReduce jobs? Include the complete data flow diagram. Both Years · 7–10 marks
08 Discuss advantages and challenges of deploying Hadoop in cloud (AWS EMR, Azure HDInsight, GCP Dataproc). How do cloud platforms enhance scalability and cost-efficiency? Both Years · 7–10 marks
09 Distinguish between data analysis and reporting in Big Data. How does advanced analytics go beyond traditional reporting to uncover hidden patterns and correlations? Both Years · 7–10 marks
⭐
TIER 2 — High Probability. Prepare complete answers. High chance of appearing in Section B or Section C.
10 What are RDDs in Apache Spark? How do they enable fault-tolerant and distributed data processing? Compare transformations vs actions. Both Years · 7–10 marks
11 Compare and contrast: (i) Apache Pig vs MapReduce (ii) Pig vs SQL (iii) Pig vs Hive — using a detailed comparison table. 2024-25 direct question
12 Define NoSQL databases. What are the key characteristics, four types, and benefits compared to traditional relational databases?
13 Explain MongoDB CRUD operations — insertOne, find, updateOne, deleteOne — with syntax examples and practical use.
14 Introduce HBase and its role in the Hadoop ecosystem. How does HBase differ from RDBMS and what advantages does it offer for large-scale data?
15 Discuss the process of developing a MapReduce application. What are the key steps in writing, testing, and deploying?
16 Discuss cluster specification. Describe how to set up a Hadoop Cluster step by step. New 2024-25
17 Explain the features and components of Apache Spark (Core, SQL, Streaming, MLlib, GraphX, Spark on YARN). New 2024-25
18 Discuss Master-Slave and Peer-Peer replication in detail with diagrams and use cases. New 2024-25
✅
TIER 3 — Short Notes (2-mark). Prepare crisp 40–60 word answers in bullet-point format. Do not skip these — they are 14 free marks.
19 Types of digital data — structured, semi-structured, unstructured — with at least one example of each.
20 What is YARN? — definition and 3 main components (ResourceManager, NodeManager, ApplicationMaster) in brief.
21 What is Apache Pig? Describe the Grunt shell and its purpose.
22 What are block sizes and block abstraction in HDFS? (128MB default, replication factor 3)
23 What is Hadoop Streaming? How does it allow non-Java programs to be used as MapReduce mappers/reducers?
24 What are the main components of the Hadoop ecosystem? List at least six with one-line role descriptions.

Model Answers

AKTU-Style Answer Writing Guide

How to structure answers, keywords to underline, diagrams to draw, and common mistakes to avoid in the AKTU Big Data exam.

Answer Length & Format Guide

MarksWord CountTimeRequired Structure
2 marks40–60 words3–4 minOne definition sentence + 2–3 concise bullet points. No diagram needed unless architecture.
7 marks250–350 words12–15 minIntroduction → Definition → Explanation (bullets) → Labelled Diagram → Conclusion
10 marks400–500 words18–20 minIntroduction → Concept → Detailed Components → Diagram → Real Examples → Conclusion

Model 2-Mark Answer: "What is YARN?"

YARN (Yet Another Resource Negotiator) is the resource management framework of Hadoop 2.x. It decouples resource management from data processing, allowing Spark, Hive, and MapReduce to share one cluster simultaneously (multi-tenancy).

Key components:
• ResourceManager — global resource allocator (master)
• NodeManager — per-node resource monitor and container launcher
• ApplicationMaster — per-application coordinator and task monitor
• Container — unit of resource allocation (specific CPU + RAM)

Model 7-Mark Answer Structure: "5 Vs of Big Data"

[Para 1 — Introduction]
Big Data refers to extremely large, complex datasets that cannot be efficiently stored, processed, or analysed using traditional database management systems. The 5 Vs are the defining characteristics that guide Big Data system architecture and design decisions.

[Para 2 — Each V with definition + example]
1. Volume — Massive quantity of data generated continuously. Facebook: 500TB/day; YouTube: 500 hours of video uploaded per minute.
2. Velocity — Speed at which data is generated and must be processed. Twitter: 6,000 tweets/sec; Stock market: microsecond-level trade data.
3. Variety — Multiple data types from diverse sources: Structured (SQL tables), semi-structured (JSON/XML), unstructured (images, videos, audio).
4. Veracity — Quality, accuracy and trustworthiness of data. IoT sensor noise, duplicate records, and inconsistent social media posts challenge data quality.
5. Value — Actionable business insights extracted from processed data. Netflix's recommendation engine drives 80% of all viewing via data-derived suggestions.

[Diagram — Draw the Pentagon model with Big Data in center, V1–V5 at corners. Takes 60 seconds and earns 1–2 extra marks.]

[Conclusion]
Understanding the 5 Vs is critical for designing appropriate storage (Volume), streaming pipelines (Velocity), data lake architecture (Variety), data quality frameworks (Veracity), and analytics solutions (Value). Together, they define the full scope of Big Data challenges.

Keywords to Underline in Exam

TopicUnderline These Keywords
5 VsVolume, Velocity, Variety, Veracity, Value, fault-tolerant, scalable, distributed
HDFSNameNode, DataNode, metadata, block replication, rack-aware, 128 MB, heartbeat, Secondary NameNode (checkpoint only)
MapReduceMap phase, Shuffle & Sort, Reduce phase, key-value pairs, input splits, JobTracker, TaskTracker, Combiner
YARNResourceManager, NodeManager, ApplicationMaster, Container, multi-tenancy, Scheduler, resource allocation
HiveHiveQL, Metastore, Driver, Compiler, Optimizer, Executor, schema-on-read, MapReduce translation
SparkRDD, Resilient, Distributed, in-memory, transformation (lazy), action (eager), DAG, lineage, 100× faster
NoSQLschema-less, horizontal scaling, BASE, eventual consistency, document, column-family, key-value, graph
HBaseHMaster, RegionServer, column-family, random access, HDFS-backed, row key, Region
PigPig Latin, Grunt shell, ETL, LOAD, FILTER, FOREACH, STORE, translates to MapReduce

Common Exam Mistakes — Avoid These

❌
Writing "Secondary NameNode is the backup of NameNode" — WRONG! Always deducted. It only checkpoints metadata (merges fsimage + edit logs). The HA NameNode (Hadoop 2.x) is the actual standby backup.
❌
Not drawing diagrams — AKTU examiners explicitly reward labelled diagrams. Even a rough box-and-arrow diagram for HDFS, MapReduce, or YARN earns 1–2 additional marks.
❌
Confusing Pig and Hive — Pig = ETL/data pipeline scripting (Pig Latin); Hive = SQL-like ad-hoc querying (HiveQL). Never interchange their descriptions.
❌
Calling MapReduce a database — it is a distributed processing framework. Data is stored in HDFS; MapReduce only processes it in batch.
❌
Writing only 3 or 4 Vs — always include all 5 Vs: Volume, Velocity, Variety, Veracity, Value. Missing any V costs marks.
✅
Always start 7/10-mark answers with a formal definition sentence. "MapReduce is a distributed data processing framework developed by Google and implemented in Apache Hadoop..."
✅
Use bullet points for listing components, advantages, and challenges — they look organised and typically score higher than dense paragraphs.
✅
End every 7/10-mark answer with a conclusion sentence. "Thus, HDFS provides fault-tolerant, scalable, distributed storage for petabyte-scale Big Data applications."

Examiner Expectations — Section-wise

Section A (2-mark answers)
• One clear definition sentence
• 2–3 crisp bullet points with technical terms
• No diagram required (unless architecture question)
• Max 3–4 lines total
• Use keywords confidently (underline them)
Section B & C (7-mark answers)
• Formal introduction paragraph
• Labelled diagram (mandatory for architecture Qs)
• Component-wise explanation with bullets
• 1–2 real-world examples
• Conclusion sentence tying it together

3-Day Strategy

Final 3-Day Exam Preparation Plan

A structured hour-by-hour schedule optimised for maximum marks in the AKTU Big Data exam (BCS061 / KCS061).

🏆
Target Strategy: Do ALL Section A first (14 easy marks) → pick best 3 from Section B → choose strongest option in each Section C question. This strategy alone = 60–68 marks if executed correctly.
1
Day 1 — Foundation & Core Hadoop (Unit 1 + Unit 2)
⏰ Morning — 2 hours
  • Memorise all 5 Vs with one real-world example each. Use mnemonic: "Very Vast Varieties Verify Value"
  • Write the Analysis vs Reporting comparison table from memory (6 rows)
  • Learn the 4 types of analytics: Descriptive, Diagnostic, Predictive, Prescriptive with "What happened / Why / What will / What to do?" triggers
  • List 8 Big Data platforms and 3 types of digital data with examples
⏰ Afternoon — 3 hours
  • Memorise all 11 Hadoop ecosystem components with their roles — write the table from memory and check
  • Understand and draw the MapReduce flow diagram from scratch: Input → Splits → Mappers → Shuffle & Sort → Reducers → Output
  • Practice the complete Word Count example through all MapReduce phases with intermediate data shown
  • Hadoop Streaming — 3-line definition + one example command
⏰ Evening — 1 hour
  • Mock: Write 2-mark answers for — What is Hadoop? What is MapReduce? What is Hadoop Streaming? Data formats in Hadoop?
  • Self-check: Write all 11 Hadoop ecosystem tools from memory. Check against the table.
2
Day 2 — Architecture Deep-Dive (Unit 3 + Unit 4)
⏰ Morning — 3 hours
  • Draw HDFS Architecture diagram from memory: Client, NameNode, Secondary NameNode (checkpoint!), 3 DataNodes with rack labels, arrows
  • Memorise HDFS Read (5 steps) and HDFS Write (7 steps) in correct order — write them out
  • Critical facts: Block = 128MB, Replication = 3, Secondary NN = NOT backup, heartbeat = 3 sec, dead after 10 min
  • Cloud Hadoop: 3 platforms (AWS EMR, Azure HDInsight, GCP Dataproc) + advantages (5 pts) + challenges (5 pts) table
⏰ Afternoon — 2.5 hours
  • Draw YARN Architecture diagram from memory: Client, ResourceManager, 2 Worker Nodes with NodeManagers + ApplicationMasters + Containers
  • YARN: Why YARN? (multi-tenancy), ResourceManager sub-components, Fair vs Capacity Scheduler
  • Spark RDDs: R-D-D full expansion, transformations (5 examples) vs actions (5 examples), why 100× faster (in-memory vs disk)
  • NoSQL 4 types: Key-Value/Document/Column-Family/Graph with one example and use case each
  • MongoDB CRUD: Write all 4 syntax examples from memory with realistic data
⏰ Evening — 1 hour
  • Timed mock: Write complete 7-mark HDFS answer (14 min) — must include the labelled architecture diagram
  • Self-check: Can you write YARN's 4 components + roles from memory?
3
Day 3 — Ecosystem Tools + Full Mock (Unit 5 + Revision)
⏰ Morning — 2.5 hours
  • Draw and explain the Hive Architecture data flow: HiveQL → Driver → Compiler ↔ Metastore → Optimizer → Executor → HDFS → Result (7 boxes, 7 steps)
  • Master the Pig vs Hive vs MapReduce vs SQL 9-row comparison table — reproduce from memory
  • HBase: HMaster + RegionServer roles + HBase vs RDBMS comparison (7 rows)
  • Pig Latin: Grunt shell, LOAD/FILTER/FOREACH/GROUP/JOIN/STORE — meaning and one example each
⏰ Afternoon — 2 hours
  • Full mock: Attempt 7 Section A short answers (2-marks each, 3 min each = 21 min)
  • Full mock: Write one complete Section C answer (7 marks, 14 minutes) — choose 5 Vs or HDFS architecture
  • Review all 5 key diagrams: Pentagon (5 Vs), MapReduce Flow, HDFS Architecture, YARN Architecture, Hive Data Flow
  • Decide in advance which 3 Section B topics you'll answer
⏰ Evening — 45 min
  • Final read-through of keywords to underline (from the Keywords table in Model Answers section)
  • Review the common mistakes list — commit to not making any of them
  • Plan exam time: Section A = 25 min → Section C = 65 min → Section B = 55 min → Review = 15 min

⚡ One-Night Emergency Plan (Only 4 Hours Available!)

HourTopics to CoverWhy — Guaranteed Marks
Hour 15 Vs of Big Data + All 11 Hadoop Ecosystem Components with rolesSection A + C guaranteed — 20–30 marks potential from these two topics alone
Hour 2MapReduce architecture diagram + HDFS architecture diagram with all labelsSure-shot 7-mark questions — appear in every single AKTU Big Data paper without exception
Hour 3YARN architecture (4 components) + Spark RDDs + Hive architecture data flowVery high probability Section B and Section C choices — covers 3 different units
Hour 4Pig vs Hive vs MapReduce comparison table + NoSQL 4 types + all 2-mark definitionsSection B options + complete coverage of all Section A short notes

Exam Day Time Management

SectionTimeApproach
Section A — 7 × 2 = 14 marks25 minAttempt ALL 7. One definition sentence + 2 bullets each. Start here — builds confidence and guarantees 14 marks.
Section C — 5 × 7 = 35 marks65 min~13 min per question. ALWAYS draw a labelled diagram. Choose the option you know better for each pair.
Section B — 3 × 7 = 21 marks55 min~18 min each. Pick your 3 strongest topics. Never attempt unfamiliar topics under time pressure.
Review15 minCheck all diagrams are labelled. Verify correct number of questions attempted. Add any missing conclusions.
🏆
Maximum Marks Strategy:
• Draw a labelled diagram for every architecture question — examiners award marks even when explanation is weak
• Underline key terms (NameNode, MapReduce, RDD, HiveQL) — signals technical accuracy to examiner
• Write a conclusion sentence for every 7-mark answer — "Thus, HDFS provides..." shows complete understanding
• Attempt Section A first to secure easy 14 marks before tackling harder questions
• In Section B, answer your best topic first — saves time and ensures your strongest answer is complete

📌 5 Key Diagrams — What to Draw in Each Unit

Fig 1 — 5 Vs Pentagon (Unit 1)

  • Pentagon shape with "Big Data" in center circle
  • 5 coloured circles at pentagon corners: V1–V5
  • Label each with name + one-word meaning
  • Dashed lines from center to each corner
  • ⏱️ Takes ~60 seconds to draw

Fig 2 — MapReduce Flow (Unit 2)

  • Input → 3 Splits → 3 Mappers → Shuffle & Sort box → 2 Reducers → Output
  • Label all boxes and all arrows with step numbers ①–⑥
  • Show key-value (k,v) on arrows between phases
  • ⏱️ Takes ~90 seconds to draw

Fig 3 — HDFS Architecture (Unit 3)

  • Client → NameNode (metadata, left) → 3 DataNodes (data, bottom)
  • Secondary NameNode connected to NameNode (checkpoint arrow)
  • Label racks: Rack 1 (DataNode 1+2), Rack 2 (DataNode 3)
  • ⏱️ Takes ~90 seconds to draw

Fig 4 — YARN Architecture (Unit 4)

  • Client → ResourceManager (master) → 2-3 Worker Nodes
  • Inside each worker: NodeManager + ApplicationMaster + Containers
  • Label all arrows: "submit job", "allocate containers"
  • ⏱️ Takes ~60 seconds to draw

Fig 5 — Hive Data Flow (Unit 5)

  • Linear: User → Driver → Compiler → Optimizer → Executor → HDFS → Result
  • Metastore connected to Compiler from below with dashed arrow
  • Number each box ①–⑦ along the top
  • ⏱️ Takes ~60 seconds to draw