RODS has been in operation for four years and, like most production systems, has acquired many fault-tolerant features. For example, at the software level, HL7 listeners continue to receive messages and temporarily store the messages when the database is off-line. A data manager program runs every ten minutes and, on finding such a cache, it loads the unstored messages to the database when the database is back on-line. In addition, the data manager program monitors and restarts HL7 listeners as necessary.