Summary

This article discusses an issue where OpsCenter 6.0 fails to start when systems have Java 9 configured as the default.

Symptoms

An attempt to start OpsCenter on a server appears to be successful however after a few seconds later, the OpsCenter daemon is no longer running and there are no new entries in the opscenterd.log despite no errors reported in the log or stdout/stderr.

Cause

On some newer Linux distributions such as Ubuntu 16.04, OpenJDK 9 is installed by default however Java 9 is not supported. Only Oracle Java 8 and OpenJDK 8 are supported for OpsCenter 6.0 as stated in the OpsCenter installation prerequisites.

Installing OpsCenter 6.0 on a server running Ubuntu 16.04 will automatically install OpenJDK 9 if Java is not already installed since that is the default behaviour on Ubuntu (internal issue ID OPSC-10788).

Solution

Ensure that Oracle Java 8 or OpenJDK 8 is already installed on the server before installing OpsCenter.

In some instances, it may be necessary to update the server with the default Java version as follows:

Step 1 - Update the system with the location of Java. For example:

$ sudo update-alternatives --install "/usr/bin/java" "java" "/usr/lib/jvm/jdk1.8.0_version/bin/java" 1

WARNING - It may be necessary to run the command above again if the initial attempt returns an error. It is known to happen if a previous version of Java was uninstalled manually.

Step 2 - Set the default Java with:

$ sudo update-alternatives --config java

Step 3 - Check the Java version. For example:

$ java -version
java version "1.8.0_65"
Java(TM) SE Runtime Environment (build 1.8.0_65-b17)
Java HotSpot(TM) 64-Bit Server VM (build 25.65-b01, mixed mode)