For the supported version of the Java Virtual Machine (JVM), see the Compatibility Matrix in the Release Notes .
As of Eucalyptus 4.3, JVM 8 is required. Eucalyptus RPM packages require java-1.8.0-openjdk, which will be installed automatically.
If your network mode is VPCMIDO, MidoNet will install JVM 1.7 as a dependency (it is acceptable to have both JVM 1.7 and JVM 1.8 installed).
To use Java with Eucalyptus cloud:
Open the /etc/eucalyptus/eucalyptus.conf file. Verify that the CLOUD_OPTS setting does not set –java-home , or that –java-home points to a supported JVM version.
Although it is possible to set , we do not recommend it unless there is a specific reason to do so.