Facing error while updating from 17.1 to 18.1

Question

Doing version update from 17.1 to 18.1 Facing the below error while starting the appian server: 
 error: Unable to start service QuorumPeerMain java.io.IOException: Cannot run program "null/bin/java" (in directory "/appian/services/zookeeper-3.4.11/bin"): error=2, No such file or directory. 
 
 But for the above issue where the java_home is set in /etc/profile. Eventhough inplace of java_home showing as null. Let me know do i need to update the java_home in any other places. 
 
 Please respond if anyone faced the above problem and how to resolve the issue.

Sergio Blazquez · Answer

The problem you have is that you didn't define a Java home path. You have to find where the jdk is installed (i.e. /usr/lib/jvm/jre-1.8.0-oracle.x86_64) and set it. Yo can set it export JAVA_HOME="path that you found" (ie export JAVA_HOME="/usr/lib/jvm/jre-1.8.0-oracle.x86_64" ) And then you can run the appian server. Also, It's recommended setting the Java path pemanently. You can do it editing the /etc/profile for instance, and adding at the bottom the export you did previously. 
 
 Edit: you can check wether the Java home is set in your current session running echo $JAVA_HOME (you don't set it for your current session editing the /etc/profile, doing that you set it for future sessions, that's the reason to execute the export in your cli)