[FLUME-1154] flume-ng script should first try finding java from PATH and then try using bigtop, instead of vice-versa

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2.0
• Fix Version/s: 1.2.0
• Component/s: Shell
• Assignee: Leslin (Hong Xiang Lin)
• Reporter: Will McQueen
• Created: 26/Apr/12 10:29
• Updated: 24/Jun/12 13:32
• Resolved: 24/Jun/12 12:48

Description

Please see bin/flume-ng script, under the "#find java" section.

It says:

1. find java
   if [ -z "${JAVA_HOME}" ] ; then
   echo "Warning: JAVA_HOME not set!"
2. Try to use Bigtop to autodetect JAVA_HOME if it's available
   if [ -e /usr/libexec/bigtop-detect-javahome ]; then
   . /usr/libexec/bigtop-detect-javahome
   elif [ -e /usr/lib/bigtop-utils/bigtop-detect-javahome ]; then
   . /usr/lib/bigtop-utils/bigtop-detect-javahome
   else
   JAVA_DEFAULT=`type -p java`
   [ -n "$JAVA_DEFAULT" ] || error "Unable to find java executable. Is it in your PATH?" 1
   JAVA_HOME=$(cd $(dirname $JAVA_DEFAULT)/..; pwd)
   fi
   fi

[ -n "${JAVA_HOME}" ] || error "Unable to find a suitable JAVA_HOME" 1

...and this means that if bigtop-detect-javahome was unable to located a java executable. This could happen if the user stores the JDK under his/her own dir in something like /home/<user>/tools/jdk1.6.0_26. The user could have the JDK bin dir in his/her path, but may not necessarily have set JAVA_HOME. If there are no other JDK's available for bigtop-utils to detect, then the current flume-ng script will fail with error saying "Unable to find a suitable JAVA_HOME", even though the java executable was in the PATH.

So, I recommend doing the "type -p java" check first, and if that results in no match then try bigtop-detect-javahome.