Error: JAVA_HOME is not set and could not be found. even though JAVA_HOME is set.

[#1]

I am trying to run HDP inside a Ubuntu 14.04 docker image. HDP 2.3.2 was installed using the official repos.

I also installed Oracle Java 8 using the webup8 package: https://launchpad.net/~webupd8team/+archive/ubuntu...

JAVA_HOME is also set correctly:

	root@3b2af516c1ce:/# echo $JAVA_HOME
	/usr/lib/jvm/java-8-oracle
	root@3b2af516c1ce:/# su hdfs
	hdfs@3b2af516c1ce:/$ echo $JAVA_HOME
	/usr/lib/jvm/java-8-oracle

However, when I try to start the name node, I get an error saying JAVA_HOME could not be found:

root@3b2af516c1ce:/# sudo -u hdfs /usr/hdp/current/hadoop-hdfs-namenode/../hadoop/sbin/hadoop-daemon.sh --config /etc/hadoop/conf start namenode

Error: JAVA_HOME is not set and could not be found.

My hadoop-env.sh has not been modified in any way:

# Set Hadoop-specific environment variables here.
# The only required environment variable is JAVA_HOME.  All others are
# optional.  When running a distributed configuration it is best to
# set JAVA_HOME in this file, so that it is correctly defined on
# remote nodes.
# The java implementation to use.
# export JAVA_HOME=${JAVA_HOME}
# The jsvc implementation to use. Jsvc is required to run secure datanodes
# that bind to privileged ports to provide authentication of data transfer
# protocol.  Jsvc is not required if SASL is configured for authentication of
# data transfer protocol using non-privileged ports.
#export JSVC_HOME=${JSVC_HOME}
#export HADOOP_CONF_DIR=${HADOOP_CONF_DIR:-"/etc/hadoop"}
# Extra Java CLASSPATH elements.  Automatically insert capacity-scheduler.
#for f in $HADOOP_HOME/contrib/capacity-scheduler/*.jar; do
#  if [ "$HADOOP_CLASSPATH" ]; then
#    export HADOOP_CLASSPATH=$HADOOP_CLASSPATH:$f
#  else
#    export HADOOP_CLASSPATH=$f
#  fi
#done
# The maximum amount of heap to use, in MB. Default is 1000.
#export HADOOP_HEAPSIZE=
#export HADOOP_NAMENODE_INIT_HEAPSIZE=""
# Extra Java runtime options.  Empty by default.
#export HADOOP_OPTS="$HADOOP_OPTS -Djava.net.preferIPv4Stack=true"
# Command specific options appended to HADOOP_OPTS when specified
#export HADOOP_NAMENODE_OPTS="-Dhadoop.security.logger=${HADOOP_SECURITY_LOGGER:-INFO,RFAS} -Dhdfs.audit.logger=${HDFS_AUDIT_LOGGER:-INFO,NullAppender} $HADOOP_NAMENODE_OPTS"
#export HADOOP_DATANODE_OPTS="-Dhadoop.security.logger=ERROR,RFAS $HADOOP_DATANODE_OPTS"
#export HADOOP_SECONDARYNAMENODE_OPTS="-Dhadoop.security.logger=${HADOOP_SECURITY_LOGGER:-INFO,RFAS} -Dhdfs.audit.logger=${HDFS_AUDIT_LOGGER:-INFO,NullAppender} $HADOOP_SECONDARYNAMENODE_OPTS"
#export HADOOP_NFS3_OPTS="$HADOOP_NFS3_OPTS"
#export HADOOP_PORTMAP_OPTS="-Xmx512m $HADOOP_PORTMAP_OPTS"
# The following applies to multiple commands (fs, dfs, fsck, distcp etc)
#export HADOOP_CLIENT_OPTS="-Xmx512m $HADOOP_CLIENT_OPTS"
#HADOOP_JAVA_PLATFORM_OPTS="-XX:-UsePerfData $HADOOP_JAVA_PLATFORM_OPTS"
# On secure datanodes, user to run the datanode as after dropping privileges.
# This **MUST** be uncommented to enable secure HDFS if using privileged ports
# to provide authentication of data transfer protocol.  This **MUST NOT** be
# defined if SASL is configured for authentication of data transfer protocol
# using non-privileged ports.
#export HADOOP_SECURE_DN_USER=${HADOOP_SECURE_DN_USER}
# Where log files are stored.  $HADOOP_HOME/logs by default.
#export HADOOP_LOG_DIR=${HADOOP_LOG_DIR}/$USER
# Where log files are stored in the secure data environment.
#export HADOOP_SECURE_DN_LOG_DIR=${HADOOP_LOG_DIR}/${HADOOP_HDFS_USER}
###
# HDFS Mover specific parameters
###
# Specify the JVM options to be used when starting the HDFS Mover.
# These options will be appended to the options specified as HADOOP_OPTS
# and therefore may override any similar flags set in HADOOP_OPTS
#
# export HADOOP_MOVER_OPTS=""
###
# Advanced Users Only!
###
# The directory where pid files are stored. /tmp by default.
# NOTE: this should be set to a directory that can only be written to by 
#       the user that will run the hadoop daemons.  Otherwise there is the
#       potential for a symlink attack.
#export HADOOP_PID_DIR=${HADOOP_PID_DIR}
#export HADOOP_SECURE_DN_PID_DIR=${HADOOP_PID_DIR}
# A string representing this instance of hadoop. $USER by default.
#export HADOOP_IDENT_STRING=$USER

Why is this happening?

[#2 · Accepted solution]

Please uncomment/configure the JAVA_HOME parameter in hadoop-env.sh

Make sure you have configured the minimal set of parameters according to this documentation: http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.3.2/bk_installing_manually_book/content/ch_setti...

Start HDFS by using the instructions explained here: http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.3.2/bk_installing_manually_book/content/format_a...

I think you might have forgotten step one=>

1. Modify the JAVA_HOME value in the hadoop-env.sh file:

   export JAVA_HOME=/usr/java/default

2. Execute the following commands on the NameNode host machine:

   su - $HDFS_USER
   /usr/hdp/current/hadoop-hdfs-namenode/../hadoop/bin/hdfs namenode -format
   /usr/hdp/current/hadoop-hdfs-namenode/../hadoop/sbin/hadoop-daemon.sh --config $HADOOP_CONF_DIR start namenode

3. Execute the following commands on the SecondaryNameNode:

   su - $HDFS_USER
   /usr/hdp/current/hadoop-hdfs-secondarynamenode/../hadoop/sbin/hadoop-daemon.sh --config $HADOOP_CONF_DIR start secondarynamenode

4. Execute the following commands on all DataNodes:

   su - $HDFS_USER
   /usr/hdp/current/hadoop-hdfs-datanode/../hadoop/sbin/hadoop-daemon.sh --config $HADOOP_CONF_DIR start datanode

Here are the first lines from one of my Ambari installed HDP cluster:

# The java implementation to use.  Required.
export JAVA_HOME=/usr/jdk64/jdk1.8.0_40
export HADOOP_HOME_WARN_SUPPRESS=1

# Hadoop home directory
export HADOOP_HOME=${HADOOP_HOME:-/usr/hdp/current/hadoop-client}

[#3]

Should I be using su on Ubuntu rather than sudo -u?

[#4]

If you are the root user, you can use su to start the services in the hdfs-user's env.

[#5]

@Jonas Straub @Vedant Jain Hi! I'm having similar issues.. I have a cluster running on 8 ec2 instances. I had to change the 'login as' to 'ec2-user' instead of 'root' when I used Ambari server to setup since ssh over root was giving me error.. Now I have 2 questions:

- Since ambari did not use root, does that mean some env variables were not set by ambari? (I had no errors installing everything)

- I can see jdk64 folder installed but its not in path.. So I cannot use 'java' commands.. Does that mean I have to go to every instance and do `export JAVA_HOME=/usr/jdk64/jdk1.8.0_40/bin/java` on every instance ? 😞

- Even after I set JAVA_HOME, I am unable to use 'jre' which I need for executing storm code!! What should I do??