Question

I am install hadoop on signal node and run program but delay time if have dataset size 3 3 GB take time about 2 hours

Answer 1

Hey @Faris!

Try increasing the number of reducers. When you increase the number of reducers, the distribution is better. I have seen in a few cases that only 1 reducer is used and this causes delay. You can set the number of reducers while running the MapReduce program. Refer to the below command:

$ hadoop <the options that you usually pass> -D mapred.reduce.tasks=<number of reducers>

Comments

Mean increasing number slaves?

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No, I mean the reducer. You are running a mapreduce program. And the job will be divided to mappers and reducers. So, I think increasing the number of reducers might help.

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How i can increasing number reduce ;please help me

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1. Export your MapReduce Java project to JAR file. 
2. Open terminal and go to the directory where you have exported the JAR file. 
3. Run the MapReduce using the following command syntax:

$ hadoop jar <jar file name> <Java class name with packagename(Ex:com.hadoop.WordCount)> <hdfs input path> <hdfs output path>