We have a web application running in WebLogic 10.3.5.0 (JDK 1.6.0) for many years now.
Two years ago and this week an intermittent NoSuchMethodError exception happens on a certain code path (reproducibly, by triggering it thru the web GUI ). The error message with names changed is:
java.lang.NoSuchMethodError: org/example/foo/bar/ApplicatonClass1.setSomeField(Ljava/lang/Long;)V]
That class is part of our app, and had that method for ten years. It happens only on one node of the cluster. After restarting that node, the error disappears and everything works fine.
In the case two years ago another method of another class was affected.
What could cause this? A redeployment gone wrong? Where to look?