It has nothing to do with OMPI - this is an ssh issue. I suspect you are simply overwhelming the connection system.
Maybe you could tell us what you are actually trying to accomplish - running thousands of mpiruns in parallel seems a tad extreme. On Jun 4, 2013, at 9:48 AM, vacate <vacatehop...@gmail.com> wrote: > Hello everyone, > > After solving my first ssh_exchange_identification problem, > I feel embarrassed to ask my another problem... :'(( > > I got some "ssh: connect to host XXX.XXX.XXX.XX port 22: connection timed > out" errors > when I mpirun over 2000 times almost at the same time. > --- > my bash shell script file : > for (( index=0; index<2000 ; index++)) > do > (time mpirun --hostfile my_hostfile openMPI_test &) >> file 2>&1 > done > --- > > But not "always" got this problem, just "often".(It seldom works well.) > In addition, the amount of "timed out" error in each test are different. > (In 2000 times, this error happened between 0~200 times) > > I try to google it, > but I can't find anyone have this ssh problem when he/she use a lot of ssh > connections... > So I think maybe someone here have had the same problem as mine. > > ---------------------------------------------------------------------------------- > > The following are some of my settings that I have tried to change : > > 1. net.ipv4.tcp_fin_timeout=180 > http://askubuntu.com/questions/21182/how-to-change-the-default-timeout-of-internet-connection > > 2. sudo iptables -A INPUT -p tcp --dport ssh -j ACCEPT > http://www.serkey.com/ubuntu-ssh-connection-timed-out-due-to-firewall-behgct.html > > ---------------------------------------------------------------------------------- > but these changes still didn't solve my problem... > > I still can't figure out where is the problem and are there some potential > problems :((( > > If someone here have any idea about this situation ,or have had the same > problem as mine? > Is it my machine problem or system problem? Or OpenMPI can't let me do > something like this? > > Really hope someone can give me a hand .. > Thank you all very very very much!! > > > Best Wishes, > Jen > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users
