Upgrading to Java 8

To get back to the Classic LOCKSS Homepage use this link

Beginning with version 1.75, the classic LOCKSS daemon requires Java 8. This page outlines the process to upgrade from Java 7 to Java 8.

Upgrade instructions

This document outlines the upgrade process for CentOS/RHEL 7 only. For CentOS/RHEL 6 and below these instructions will not work. Please email lockss-support@lockss.org for further instructions.

Check the currently installed Java version:

java -version

If the output indicates a version number beginning with 1.8, Java 8 is already installed, no further action is needed. Example:

openjdk version "1.8.0_265"
OpenJDK Runtime Environment (build 1.8.0_265-b01)
OpenJDK 64-Bit Server VM (build 25.265-b01, mixed mode)

If the output indicates a version number beginning with 1.7, Java 7 needs to be uninstalled and Java 8 installed. Example:

java version "1.7.0_221"
OpenJDK Runtime Environment (rhel-2.6.18.0.el7_6-x86_64 u221-b02)
OpenJDK 64-Bit Server VM (build 24.221-b02, mixed mode)

Login as root (or gain root privilege)
Stop the LOCKSS daemon:
```
systemctl stop lockss
```
Uninstall Java 7; the two versions can live alongside each other but we recommend uninstalling Java 7:
```
yum remove java-1.7.0-openjdk
yum remove java-1.7.0-openjdk-headless
```
If you installed the Java 7 JDK, remove it too:
```
yum remove java-1.7.0-openjdk-devel
```
Install the Java 8 JRE:
```
yum install java-1.8.0-openjdk
```
Verify that Java 8 is installed by checking the version number:
```
java -version
```
Restart the LOCKSS daemon:
```
systemctl start lockss
```