The long-term goal of the Open MPI implementation is to terminate all processes in all tasks that contain a process in \fIcomm\fP, and the error code is not returned to the invoking environment. At the moment, this isn't fully implemented and MPI_Abort will terminate the entire job. The Java implementation currently does not allow specification of a communicator and aborts the entire job - this will be updated to support the long-term implementation at a later date.
Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ and Java functions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI::Exception object - similar behavior is followed by Java.
Before the error value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job, except for I/O function errors. The error handler
may be changed with MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.