We upgraded Platform from version 1.9.7 to version 1.11.5 a week ago, with Apache-tomact7, Java 8 and mysql 5.6. I realize a problem with Java app, where after sometimes java creates another thread(2) whenever we restart
services causing a system downtime. A tomcat7 restart does not stop previous java thread. I’m forced to kill java threads, then restart services for AMRS to work.
It looks like Tomcat 7 only supports Java 6 and 7.[ref]
If trying an earlier version of Java to see if it resolves the problem, I would try Java 7 (not Java 6), since Java 7 has only been unsupported for a year.