If we have more than one Java version installed on your Linux server (Redhat flavor) you can change defaults using ‘alternatives’ command:
[hadoop@ip-172-31-36-252 ~]$ sudo /usr/sbin/alternatives --config java There are 2 programs which provide 'java'. Selection Command ----------------------------------------------- *+ 1 /usr/lib/jvm/jre-1.7.0-openjdk.x86_64/bin/java 2 /usr/lib/jvm/jre-1.8.0-openjdk.x86_64/bin/java Enter to keep the current selection[+], or type selection number: 2 [hadoop@ip-172-31-36-252 ~]$ sudo /usr/sbin/alternatives --config java There are 2 programs which provide 'java'. Selection Command ----------------------------------------------- * 1 /usr/lib/jvm/jre-1.7.0-openjdk.x86_64/bin/java + 2 /usr/lib/jvm/jre-1.8.0-openjdk.x86_64/bin/java Enter to keep the current selection[+], or type selection number: [hadoop@ip-172-31-36-252 ~]$
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