Introduction to Hadoop and Its Components

Pre-Digital Era Data

• Small amounts of data generated slowly
• Mostly structured (documents, rows, columns)
• Single storage unit and processor were sufficient

Rise of Big Data

• Internet led to vast amounts of data generated in multiple formats
  • Emails, images, audio, video (semi-structured and unstructured)
• Handling became impossible with traditional methods

Need for a New Solution

• Required multiple storage units and processors
• Hadoop framework developed for efficient storage and processing

Components of Hadoop

1. Hadoop Distributed File System (HDFS)

   • Storage unit of Hadoop
   • Data stored in blocks across multiple computers (default block size: 128MB)
   • Replication method ensures fault tolerance (replication factor: 3)

2. MapReduce

   • Data processing unit of Hadoop
   • Splits data into parts, processes separately, then aggregates results
   • Example: Counting occurrences of words
     • Split input into parts
     • Mapper phase: count each word
     • Shuffle, sort, and group similar words
     • Reducer phase: give count to grouped words
     • Aggregated result as output
   • Improves load balancing and time efficiency

3. YARN (Yet Another Resource Negotiator)

   • Manages cluster resources: RAM, network bandwidth, CPU
   • Components:
     • Resource Manager: Assigns resources
     • Node Manager: Handles nodes and monitors resource usage
     • Containers: Hold physical resources
     • Application Master: Requests containers for processing jobs

Hadoop Ecosystem

• Additional tools and frameworks for managing, processing, and analyzing data
• Components include:
  • Hive
  • Pig
  • Apache Spark
  • Flume
  • Scoop

Applications of Hadoop

• Data warehousing
• Recommendation systems
• Fraud detection

Interactive Question

• Question: What is the advantage of the 3x replication schema in HDFS?
  • a) Supports parallel processing
  • b) Faster data analysis
  • c) Ensures fault tolerance
  • d) Manages cluster resources
• Leave your answers in the comment section
• Chance to win Amazon gift vouchers

Conclusion

• Hadoop is a game changer for businesses (used by Facebook, IBM, eBay, Amazon)
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