3.4 IIOP Client Failover
It is not always possible to determine when a server instance failed with respect to the work it was doing at the time of failure. For example, if a server instance fails after handling a client request but before returning the response, there is no way to tell that the request was handled. A user that does not get a response will most likely retry, resulting in an additional request.
Support for IIOP client failover has been added to Oracle Tuxedo CORBA as an availability enhancement. IIOP client failover provides a transparent mechanism for a CORBA remote client to automatically connect to an alternative ISL and then retry the request in case of failure.
IIOP client failover marks an interface implementation as
idempotent. An idempotent implementation is one that can be
repeated without any negative side-effects. For example,
SET
BALANCE.