We added a new Ubuntu server to deploy one of our new feature to isolate it from the core modules. The new module did not work, and we narrowed it to System.currentTimeMillis() returning a time in the future.
NTP was active; we ran the linux “date” command and it was showing the correct date. When we checked Glassfish’s JVM report, it showed that the user.timezone was different, and the timezone difference coincides with the time differences we observed. The straightforward answer: set -Duser.timezone in the JVM options and we are good to go.
But wait, why our original servers didn’t have this issue? We checked the original server, and there was no such JVM option setting. After some tracing it turns out that /etc/timezone of the new server was incorrect, and that influenced the timezone Glassfish used. Finally we matched the two server settings and reverted the user.timezone JVM option.