hadoop2

How can I access S3/S3n from a local Hadoop 2.6 installation?

For some reason, the jar hadoop-aws-[version].jar which contains the implementation to NativeS3FileSystem is not present in the classpath of hadoop by default in the version 2.6 & 2.7. So, try and add it to the classpath by adding the following line in hadoop-env.sh which is located in $HADOOP_HOME/etc/hadoop/hadoop-env.sh: export HADOOP_CLASSPATH=$HADOOP_CLASSPATH:$HADOOP_HOME/share/hadoop/tools/lib/* Assuming you are using Apache … Read more

There are 0 datanode(s) running and no node(s) are excluded in this operation

Two things worked for me, STEP 1 : stop hadoop and clean temp files from hduser sudo rm -R /tmp/* also, you may need to delete and recreate /app/hadoop/tmp (mostly when I change hadoop version from 2.2.0 to 2.7.0) sudo rm -r /app/hadoop/tmp sudo mkdir -p /app/hadoop/tmp sudo chown hduser:hadoop /app/hadoop/tmp sudo chmod 750 /app/hadoop/tmp … Read more

While writing to hdfs path getting error java.io.IOException: Failed to rename

You can do all the selects in one single job, get all the selects and union in a single table. Dataset<Row> resultDs = givenItemList.parallelStream().map( item -> { String query = “select $item as itemCol , avg($item) as mean groupBy year”; return sparkSession.sql(query); }).reduce((a, b) -> a.union(b)).get saveDsToHdfs(hdfsPath, resultDs );

Hadoop “Unable to load native-hadoop library for your platform” warning

I assume you’re running Hadoop on 64bit CentOS. The reason you saw that warning is the native Hadoop library $HADOOP_HOME/lib/native/libhadoop.so.1.0.0 was actually compiled on 32 bit. Anyway, it’s just a warning, and won’t impact Hadoop’s functionalities. Here is the way if you do want to eliminate this warning, download the source code of Hadoop and … Read more