Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                
SlideShare a Scribd company logo
Presented By,
KELLY TECHNOLOGIES
WWW.KELLYTECHNO.COM
1. Introduction: Hadoop’s history and
advantages
2. Architecture in detail
3. Hadoop in industry
 Hadoop is an open source framework which
is composed in java by apache software
foundation.
 This framework is utilized to write software
application which requires to process
unfathomable measure of information (It
could handle with multi tera bytes of
information).
Doug Cutting
2005: Doug Cutting and Michael J. Cafarella developed
Hadoop to support distribution for the Nutch search
engine project.
The project was funded by Yahoo.
2006: Yahoo gave the project to Apache
Software Foundation.
2003
2004
2006
• 2008 - Hadoop Wins Terabyte Sort Benchmark (sorted 1 terabyte of
data in 209 seconds, compared to previous record of 297 seconds)
• 2009 - Avro and Chukwa became new members of Hadoop
Framework family
• 2010 - Hadoop's Hbase, Hive and Pig subprojects completed, adding
more computational power to Hadoop framework
• 2011 - ZooKeeper Completed
• 2013 - Hadoop 1.1.2 and Hadoop 2.0.3 alpha.
- Ambari, Cassandra, Mahout have been added
• Hadoop:
• an open-source software framework that supports data-
intensive distributed applications, licensed under the
Apache v2 license.
• Goals / Requirements:
• Abstract and facilitate the storage and processing of
large and/or rapidly growing data sets
• Structured and non-structured data
• Simple programming models
• High scalability and availability
• Use commodity (cheap!) hardware with little redundancy
• Fault-tolerance
• Move computation rather than data
• Distributed, with some centralization
• Main nodes of cluster are where most of the computational power
and storage of the system lies
• Main nodes run TaskTracker to accept and reply to MapReduce
tasks, and also DataNode to store needed blocks closely as
possible
• Central control node runs NameNode to keep track of HDFS
directories & files, and JobTracker to dispatch compute tasks to
TaskTracker
• Written in Java, also supports Python and Ruby
Hadoop training in bangalore
• Hadoop Distributed Filesystem
• Tailored to needs of MapReduce
• Targeted towards many reads of filestreams
• Writes are more costly
• High degree of data replication (3x by default)
• No need for RAID on normal nodes
• Large blocksize (64MB)
• Location awareness of DataNodes in network
NameNode:
• Stores metadata for the files, like the directory structure of a
typical FS.
• The server holding the NameNode instance is quite crucial,
as there is only one.
• Transaction log for file deletes/adds, etc. Does not use
transactions for whole blocks or file-streams, only metadata.
• Handles creation of more replica blocks when necessary
after a DataNode failure
DataNode:
• Stores the actual data in HDFS
• Can run on any underlying filesystem (ext3/4, NTFS, etc)
• Notifies NameNode of what blocks it has
• NameNode replicates blocks 2x in local rack, 1x elsewhere
Hadoop training in bangalore
MapReduce Engine:
• JobTracker & TaskTracker
• JobTracker splits up data into smaller tasks(“Map”) and
sends it to the TaskTracker process in each node
• TaskTracker reports back to the JobTracker node and
reports on job progress, sends data (“Reduce”) or requests
new jobs
• None of these components are necessarily limited to using
HDFS
• Many other distributed file-systems with quite different
architectures work
• Many other software packages besides Hadoop's
MapReduce platform make use of HDFS
• Hadoop is in use at most organizations that handle big data:
o Yahoo!
o Facebook
o Amazon
o Netflix
o Etc…
• Some examples of scale:
o Yahoo!’s Search Webmap runs on 10,000 core Linux
cluster and powers Yahoo! Web search
o FB’s Hadoop cluster hosts 100+ PB of data (July, 2012)
& growing at ½ PB/day (Nov, 2012)
• Advertisement (Mining user behavior to generate
recommendations)
• Searches (group related documents)
• Security (search for uncommon patterns)
Three main applications of Hadoop:
• Non-realtime large dataset computing:
o NY Times was dynamically generating PDFs of articles
from 1851-1922
o Wanted to pre-generate & statically serve articles to
improve performance
o Using Hadoop + MapReduce running on EC2 / S3,
converted 4TB of TIFFs into 11 million PDF articles in
24 hrs
• System requirements
o High write throughput
o Cheap, elastic storage
o Low latency
o High consistency (within a
single data center good
enough)
o Disk-efficient sequential
and random read
performance
• Classic alternatives
o These requirements typically met using large MySQL cluster &
caching tiers using Memcached
o Content on HDFS could be loaded into MySQL or Memcached
if needed by web tier
• Problems with previous solutions
o MySQL has low random write throughput… BIG problem for
messaging!
o Difficult to scale MySQL clusters rapidly while maintaining
performance
o MySQL clusters have high management overhead, require
more expensive hardware
• Facebook’s solution
o Hadoop + HBase as foundations
o Improve & adapt HDFS and HBase to scale to FB’s workload
and operational considerations
 Major concern was availability: NameNode is SPOF &
failover times are at least 20 minutes
 Proprietary “AvatarNode”: eliminates SPOF, makes HDFS
safe to deploy even with 24/7 uptime requirement
 Performance improvements for realtime workload: RPC
timeout. Rather fail fast and try a different DataNode
 Distributed File System
 Fault Tolerance
 Open Data Format
 Flexible Schema
 Queryable Database
 Need to process Multi Petabyte Datasets
 Data may not have strict schema
 Expensive to build reliability in each
application
 Nodes fails everyday
 Need common infrastructure
 Very Large Distributed File System
 Assumes Commodity Hardware
 Optimized for Batch Processing
 Runs on heterogeneous OS
 A Block Sever
 Stores data in local file system
 Stores meta-data of a block - checksum
 Serves data and meta-data to clients
 Block Report
 Periodically sends a report of all existing
blocks to NameNode
 Facilitate Pipelining of Data
 Forwards data to other specified
DataNodes
 Replication Strategy
 One replica on local node
 Second replica on a remote rack
 Third replica on same remote rack
 Additional replicas are randomly placed
 Clients read from nearest replica
 Use Checksums to validate data – CRC32
 File Creation
 Client computes checksum per 512 byte
 DataNode stores the checksum
 File Access
 Client retrieves the data and checksum from DataNode
 If validation fails, client tries other replicas
 Client retrieves a list of DataNodes on which to
place replicas of a block
 Client writes block to the first DataNode
 The first DataNode forwards the data to the
next DataNode in the Pipeline
 When all replicas are written, the client moves
on to write the next block in file
 MapReduce programming model
 Framework for distributed processing of large data
sets
 Pluggable user code runs in generic framework
 Common design pattern in data processing
 cat * | grep | sort | uniq -c | cat > file
 input | map | shuffle | reduce | output
 Log processing
 Web search indexing
 Ad-hoc queries
 MapReduce Component
 JobClient
 JobTracker
 TaskTracker
 Child
 Job Creation/Execution Process
THANK
YOU!!!
www.Kellytechno.com

More Related Content

Hadoop training in bangalore

  • 2. 1. Introduction: Hadoop’s history and advantages 2. Architecture in detail 3. Hadoop in industry
  • 3.  Hadoop is an open source framework which is composed in java by apache software foundation.  This framework is utilized to write software application which requires to process unfathomable measure of information (It could handle with multi tera bytes of information).
  • 4. Doug Cutting 2005: Doug Cutting and Michael J. Cafarella developed Hadoop to support distribution for the Nutch search engine project. The project was funded by Yahoo. 2006: Yahoo gave the project to Apache Software Foundation.
  • 6. • 2008 - Hadoop Wins Terabyte Sort Benchmark (sorted 1 terabyte of data in 209 seconds, compared to previous record of 297 seconds) • 2009 - Avro and Chukwa became new members of Hadoop Framework family • 2010 - Hadoop's Hbase, Hive and Pig subprojects completed, adding more computational power to Hadoop framework • 2011 - ZooKeeper Completed • 2013 - Hadoop 1.1.2 and Hadoop 2.0.3 alpha. - Ambari, Cassandra, Mahout have been added
  • 7. • Hadoop: • an open-source software framework that supports data- intensive distributed applications, licensed under the Apache v2 license. • Goals / Requirements: • Abstract and facilitate the storage and processing of large and/or rapidly growing data sets • Structured and non-structured data • Simple programming models • High scalability and availability • Use commodity (cheap!) hardware with little redundancy • Fault-tolerance • Move computation rather than data
  • 8. • Distributed, with some centralization • Main nodes of cluster are where most of the computational power and storage of the system lies • Main nodes run TaskTracker to accept and reply to MapReduce tasks, and also DataNode to store needed blocks closely as possible • Central control node runs NameNode to keep track of HDFS directories & files, and JobTracker to dispatch compute tasks to TaskTracker • Written in Java, also supports Python and Ruby
  • 10. • Hadoop Distributed Filesystem • Tailored to needs of MapReduce • Targeted towards many reads of filestreams • Writes are more costly • High degree of data replication (3x by default) • No need for RAID on normal nodes • Large blocksize (64MB) • Location awareness of DataNodes in network
  • 11. NameNode: • Stores metadata for the files, like the directory structure of a typical FS. • The server holding the NameNode instance is quite crucial, as there is only one. • Transaction log for file deletes/adds, etc. Does not use transactions for whole blocks or file-streams, only metadata. • Handles creation of more replica blocks when necessary after a DataNode failure
  • 12. DataNode: • Stores the actual data in HDFS • Can run on any underlying filesystem (ext3/4, NTFS, etc) • Notifies NameNode of what blocks it has • NameNode replicates blocks 2x in local rack, 1x elsewhere
  • 14. MapReduce Engine: • JobTracker & TaskTracker • JobTracker splits up data into smaller tasks(“Map”) and sends it to the TaskTracker process in each node • TaskTracker reports back to the JobTracker node and reports on job progress, sends data (“Reduce”) or requests new jobs
  • 15. • None of these components are necessarily limited to using HDFS • Many other distributed file-systems with quite different architectures work • Many other software packages besides Hadoop's MapReduce platform make use of HDFS
  • 16. • Hadoop is in use at most organizations that handle big data: o Yahoo! o Facebook o Amazon o Netflix o Etc… • Some examples of scale: o Yahoo!’s Search Webmap runs on 10,000 core Linux cluster and powers Yahoo! Web search o FB’s Hadoop cluster hosts 100+ PB of data (July, 2012) & growing at ½ PB/day (Nov, 2012)
  • 17. • Advertisement (Mining user behavior to generate recommendations) • Searches (group related documents) • Security (search for uncommon patterns) Three main applications of Hadoop:
  • 18. • Non-realtime large dataset computing: o NY Times was dynamically generating PDFs of articles from 1851-1922 o Wanted to pre-generate & statically serve articles to improve performance o Using Hadoop + MapReduce running on EC2 / S3, converted 4TB of TIFFs into 11 million PDF articles in 24 hrs
  • 19. • System requirements o High write throughput o Cheap, elastic storage o Low latency o High consistency (within a single data center good enough) o Disk-efficient sequential and random read performance
  • 20. • Classic alternatives o These requirements typically met using large MySQL cluster & caching tiers using Memcached o Content on HDFS could be loaded into MySQL or Memcached if needed by web tier • Problems with previous solutions o MySQL has low random write throughput… BIG problem for messaging! o Difficult to scale MySQL clusters rapidly while maintaining performance o MySQL clusters have high management overhead, require more expensive hardware
  • 21. • Facebook’s solution o Hadoop + HBase as foundations o Improve & adapt HDFS and HBase to scale to FB’s workload and operational considerations  Major concern was availability: NameNode is SPOF & failover times are at least 20 minutes  Proprietary “AvatarNode”: eliminates SPOF, makes HDFS safe to deploy even with 24/7 uptime requirement  Performance improvements for realtime workload: RPC timeout. Rather fail fast and try a different DataNode
  • 22.  Distributed File System  Fault Tolerance  Open Data Format  Flexible Schema  Queryable Database
  • 23.  Need to process Multi Petabyte Datasets  Data may not have strict schema  Expensive to build reliability in each application  Nodes fails everyday  Need common infrastructure  Very Large Distributed File System  Assumes Commodity Hardware  Optimized for Batch Processing  Runs on heterogeneous OS
  • 24.  A Block Sever  Stores data in local file system  Stores meta-data of a block - checksum  Serves data and meta-data to clients  Block Report  Periodically sends a report of all existing blocks to NameNode  Facilitate Pipelining of Data  Forwards data to other specified DataNodes
  • 25.  Replication Strategy  One replica on local node  Second replica on a remote rack  Third replica on same remote rack  Additional replicas are randomly placed  Clients read from nearest replica
  • 26.  Use Checksums to validate data – CRC32  File Creation  Client computes checksum per 512 byte  DataNode stores the checksum  File Access  Client retrieves the data and checksum from DataNode  If validation fails, client tries other replicas
  • 27.  Client retrieves a list of DataNodes on which to place replicas of a block  Client writes block to the first DataNode  The first DataNode forwards the data to the next DataNode in the Pipeline  When all replicas are written, the client moves on to write the next block in file
  • 28.  MapReduce programming model  Framework for distributed processing of large data sets  Pluggable user code runs in generic framework  Common design pattern in data processing  cat * | grep | sort | uniq -c | cat > file  input | map | shuffle | reduce | output
  • 29.  Log processing  Web search indexing  Ad-hoc queries
  • 30.  MapReduce Component  JobClient  JobTracker  TaskTracker  Child  Job Creation/Execution Process