Dear MPICH2, Can you please help me with understanding Fault Tolerance in MPICH3.0.4 I have a simple MPI program: Master calls MPI_Irecv + MPI_Wait in loop. Single slave: calls MPI_Send x 5 times, then calls abort. When I execute program with MPICH2 hydra I get multiple times Master process prints about fail in slave. In MPICH3 hydra I get a single message about fail of slave and then Master process enters to endless wait for next Irecv completion. In both cases I compiled program with MPICH3.0.4 In other words, with MPICH2 hydra each Irecv completes (even if slave died before execution of Irecv) but in MPICH3 hydra not. Causes MPI_Irecvendless wait. If I compile same program with MPICH2 and use MPICH2 hydra, I get the same result as compiling with MPICH3.0.4 and running with MPICH2 hydra. Execution command: mpiexec.hydra -genvall -disable-auto-cleanup -f MpiConfigMachines1.txt-launcher= rsh -n 2 mpi_irecv_ft_simple Both hydra's configured with: $ ./configure --prefix=/space/local/mpich-3.0.4/ --enable-error-checking= runtime --enable-g=dbg CFLAGS=-fPIC CXXFLAGS=-fPIC FFLAGS=-fpic--enable-threads= runtime --enable-totalview --enable-static --disable-f77 --disable-fc--no-recursion $ ./configure --prefix=/space/local/mpich2-1.5b2/ --enable-error-checking= runtime --enable-g=dbg CFLAGS=-fPIC CXXFLAGS=-fPIC FFLAGS=-fpic--enable-threads= runtime --enable-totalview --enable-static --disable-f77 --disable-fc Can you advice please? Regards, Anatoly.