After a recent issue with upgrading JIRA (where older Java version was not supported anymore), I was surprised that the JIRA installer did not check for prerequisites during installation (I am talking about Windows installer upgrading an existing installation). It's my fault completely for failing to read the supported platforms page at all, but nevertheless it would still be nice to prevent people from shooting themselves in the foot (and possibly reducing number of support requests in the long run).

There are at least two places I can think of where a "fail fast" approach would be of more help:

1. JIRA Installer should check which Java version is installed and fail if it is not supported.
2. Batch scripts for the JIRA service installation should not try to guess the JIRA path, but instead fail immediately if JRE_HOME and JAVA_HOME are not defined. Otherwise it's easy to get the incorrect Java instance running for the Tomcat service, even though there are no warnings during installation. Right now the script checks JRE_HOME, then JAVA_HOME and then defaults to a bundled JRE installation (and the resulting folder looks "funny" like described here).

Finally, docs on configuring JAVA_HOME should be clarified to remove ambiguities. All over the Atlassian site, it's suggested to define JAVA_HOME to point to Java JRE folder. On the other hand, if you install Bamboo, it requires that JAVA_HOME is pointing to Java JDK. Even the batch script which installs JIRA as a service first checks if JRE_HOME is defined, instead of JAVA_HOME.

It seems a correct setup would be:

• JAVA_HOME - points to JDK (needed for Bamboo, and not needed at all if you are only running JIRA),
• JRE_HOME - points to JRE (also including the bundled JRE)
• service scripts checks if they are indeed pointing to correct folders and fails as soon as one of these variables is configured incorrectly.