Category Archives: Hadoop

Load Oracle Table to Spark and Create an External Table using Scala (#Hadoop #Oracle #Scala #Spark)

In this blog post, I would like to demonstrate the steps to load RDBMS table (Oracle in this case) into Spark and Create an External table. Before we start the actual steps, lets understand few of the definitions which are … Continue reading

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Exception in thread “main” java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.JobContext, but class was expected

Issue: While configuring Sqoop (Sqoop: Downloaded was 1.4.6) on HDFS (Hadoop: 2.7.2), I encountered the below error, Exception in thread “main” java.lang.IncompatibleClassChangeError: Found interface org.apache.hadoop.mapreduce.JobContext, but class was expected        at org.apache.sqoop.config.ConfigurationHelper.getJobNumMaps(ConfigurationHelper.java:65)        at com.cloudera.sqoop.config.ConfigurationHelper.getJobNumMaps(ConfigurationHelper.java:36)        at org.apache.sqoop.mapreduce.db.DataDrivenDBInputFormat.getSplits(DataDrivenDBInputFormat.java:125) Cause: Could be something to do … Continue reading

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Incorrect configuration: namenode address dfs.namenode.servicerpc-address or dfs.namenode.rpc-address is not configured.

Issue: While configuring Apache Hadoop 2.7.2, I encountered the error stated. Incorrect configuration: namenode address dfs.namenode.servicerpc-address or dfs.namenode.rpc-address is not configured.   Cause: Could be something to do with core-site.xml   Resolution: There was a space after “fs.default.name” and before </name> … Continue reading

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Hadoop 2.7.2 Pseudo Distributed Install on RHEL 7.2

The install of Hadoop is very simple if we split the steps into the main categories. Pre-Install Steps: User/Group Creation for Hadoop Install Password less SSH between the server(s) Download the Hadoop & Java Software Install Steps: Set the Path … Continue reading

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