I have an environment with a GlassFish cluster. Each instance must have access to a password string that must not be stored on the instances. Thus it has to be entered upon instance startup by an administrator. Once entered on one instance other servers in the cluster should be able to gain access to this value automatically so that it only has to be re-entered when all instances go down. Is there some best practice to solve this with Java EE/GlassFish?