hadoop map reduce

WDABT 2016 – BHARATHIAR UNIVERSITY

K.Santhiya , Ph.d Research Scholar , Dr.V.Bhuvaneswari, Asst.Professor, Dept. of Comp. Appll., Bharathiar University,- WDABT 2016

Take a Closer Look at

Presented ByK.SANTHIYA

Ph.d Research Scholar

Under the Guidance ofDr.V.BHUVANESWARI

Assistant ProfessorDepartment of Computer Applications

Bharathiar UniversityK.Santhiya , Ph.d Research Scholar , Dr.V.Bhuvaneswari, Asst.Professor, Dept. of Comp. Appll., Bharathiar

University,- WDABT 2016

AGENDA

• MAPREDUCE• ANALOGY• EXECUTION• HADOOP INTERACTION• BUILD MAPREDUCE PROGRAM IN ECLIPSE

YARN• YARN DEFINITION• YARN REAL LIFE CONNECT• YARN INRASTRUCTURE


WHY MAPREDUCE


MAP REDUCE


REAL TIME USES OF MAP REDUCE


MR REAL – LIFE CONNECT


MAP REDUCE - ANALOGY


MAP REDUCE – ANALOGY CONTD.,


MAP REDUCE EXAMPLE


MAP EXECUTION


MAP EXECUTION – DISTRIBUTED TWO NODE ENVIRONMENT


MAPREDUCE JOBS


HADOOP JOB WORK INTERACTION


CHARACTERISTICS OF MR

• MapReduce is designed to handle very large scale data in the range of petabytes and exabytes.

• It works well on write once and read many data, also known as WORM data.

• MapReduce allows parallelism without mutexes.• The Map and Reduce operations are performed by the

same processor.• Operations are provisioned near the data as data locality is

preferred.• Commodity hardware and storage is leveraged in

MapReduce. • The runtime takes care of splitting and moving data for

operations.K.Santhiya , Ph.d Research Scholar , Dr.V.Bhuvaneswari, Asst.Professor, Dept. of Comp. Appll., Bharathiar University,-

WDABT 2016

BUSINESS SCENARIO


SET UP ENVIRONMENT


SMALL DATA AND BIG DATA


UPLOADING SMALL & BIG DATA


BUILD MAPREDUCE PROGRAM


MAPREDUCE DEMO

• We will be running an example to compute the value of ‘pi’, which is a computation intensive program. The first argument indicates how many maps to create. Here, we use 10 mappers. The second argument indicates how many samples are generated per map; here, we take 100 random samples. So this program uses 10 multiplied by 100, that is, 1000 random points to estimate pi. We could enhance 100 to 10 million and improve accuracy.


HADOOP MR REQUIREMENTS


Create a New Project : Step 1


CHECKING HADOOP ENVIRONMENT FOR MAPREDUCE


Build a MR Application Using Eclipse and Run in Hadoop Cluster

Let’s build a MapReduce Java program in Eclipse and then run in our Hadoop cluster. In this demo, we will run Eclipse in the Windows development machine and our Hadoop cluster will be in Ubuntu.

• First, let’s launch Eclipse.• 2. Enter the workspace location.• 3. Click OK• 4. The Eclipse window will open. • 5. Close the welcome screen of Eclipse.• 6. Select the New menu item. • 7. Select Java Project.• 8. The New Java Project window opens. • 9. We will be build a WordCount program here to count the number of times

each word occurs in a particular file.


Build a MR Application Using Eclipse and Run in Hadoop Cluster Contd.,

10. Enter the name of the project as ‘WordCount’ and click Finish. 11. Right click the WordCount project in the panel on the left. 12. Select New and then Class. 13. The New Java Class window opens. 14. Enter the name of the class as ‘WordCount’. 15. Click Finish.

16. Now, let’s copy the WordCount program from the MapReduce tutorial on Hadoop’s website. You may go to Hadoop’s documentation or directly go to the link being shown.

17. Copy the source code for the Word Count program. 18. You would notice a lot of compilation errors. Let’s fix the build patch now.

Select the project WordCount.



19. Select the Project menu item. 20. Click Properties.21. In libraries, add external JARs. 22. Browse to the unpacked Hadoop directory and go to share- Hadoop- MapReduce

directory. 23. Select the Hadoop MapReduce client core and Hadoop MapReduce client common

JAR files. 24. Now, go to share-Hadoop-common directory. 25. Select the Hadoop common JAR file. 26. The compilation errors would have gone by now. 27. Let’s now see various portions of this program. 28. The usual Java imports are at the top of the program. 29. Further, there are Hadoop and MapReduce related import statements. Select the

Description column header.



30. In the main method, we begin by setting configuration of the MapReduce job.31. We set the name of the Mapper class.32. We set the name of Combiner class.33. Similarly, there is a Reducer class. 34. We can set the output key class. 35. We can also set the output value class. 36. Also, set the input data path for the source dataset. 37. Set the output path to a location where the results are desired.38. Our Mapper class extends Mapper. 39. It has a map method which takes key and value as arguments and uses context. 40. In the WordCount logic, we just tokenize each line by space character and

extract individual words.



41. Our Reducer class similarly extends Reducer.42. The Reduce method takes a key and an iterable list of values as arguments.43. The final output is again written as key value pairs.44. Select the New menu item. 45. Let’s now build and export a JAR file to run this program on a Hadoop

cluster. Click File menu and then Export. 46. The Export window opens. 47. Expand Java. 48. Select JAR file.49. Click the Next button. 50. Enter the path and name of JAR. In this case, let’s name it

‘WordCount.jar’.



51. Make sure that you to select the project. 52. Now, let’s transfer this JAR to the Hadoop cluster. If you are using

Windows, you can use any SCP or FTP client such as WinSCP. Login to WinSCP using the IP address of the Hadoop Ubuntu cluster.

53. Enter the username of the Hadoop machine. 54. Enter the password. 55. Select the WordCount.jar file from the local Windows machine. 56. Using WinSCP, you can drag and drop to the Ubuntu machine in the panel

on the right. 57. The Copy window opens. 58. Click the Copy button.



59. Now, run the WordCount program in the Hadoop cluster using the hadoop jar command. Specify the input file name on which WordCount is to be applied and also the output result path.

60. View the results in the output directory. 61. You will notice a file named similar to the part Out1.62. View the contents of this output file using the hadoop fs -cat command.63. The output will have a count of each word’s occurrence in the input

dataset.


WHY YARN ?YARN : Yet Another Resource Navigator


WHAT IS YARN ?

YARN is a resource manager. It was created by separating the processing engine and the management function of MapReduce. It monitors and manages workloads, maintains a multi-tenant environment, manages the high availability features of Hadoop, and implements security controls.


YARN – REAL LIFE CONNECT

• Limitations of MapReduce• Architected by Yahoo• Hadoop 2.0 provides a broader ecosystem

with

– Spark for Iterative processing– Storm for Stream processing– Hadoop for Batch processing


YARN INFRASTRUCTURE


REFERENCES• (2012) Carl W. Olofson, Dan Vesset.

Worldwide Hadoop – MapReduce Ecosystem Software 2012-2016 Forecast [Online] Available : http://www.idc.com/getdoc.jsp?containerId=234294

• Philip Russom , " Big Data Analytics " , presented by tdwi , 2011

• K. Cukier, “Data, data everywhere,'' Economist, vol. 394, no. 8671,pp. 3_16, 2010


hadoop map reduce

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