On a headless (==without console) network server, the Oracle 11g JDBC driver used for (Java) application connections may cause trouble. In my case, it refused to connect to the DB Server without providing any error, trace or log entry. It simply hung. After several hours, it connected one time, and froze again.
Tagged database, development, java, public via Pocket, added: March 18, 2014 at 10:35PM