As I have mentioned in the previous mail (I posted one before this), the
rpi module which is used depends on what is available (or in other words
which module is ready to run). With regards to security issues involved,
we do not do anything to make things secure :-D. Could you specify what
exactly you mean by the network characteristics?
Anju
> Thank you for your fast reply....
>
> so i can say that for example when i send a array with integers from node 0
> to node 1 there are transported with tcp? ...but how informations
> are transportet between the lam daemons (lamd)? And when i use lam mpi
> between far away nodes (cluster) for example use over the internet...
> is this not dangerous because udp is connectinless? where can i get
> informations about network characteristics of LAM MPI?
>
> thank you
>
> ----- Original Message -----
> From: "Prabhanjan Kambadur" <pkambadu_at_[hidden]>
> To: "General LAM/MPI mailing list" <lam_at_[hidden]>
> Sent: Thursday, June 17, 2004 11:11 PM
> Subject: Re: LAM: transport protocol and rsh ssh configuration
>
>
> >
> > Hi,
> >
> > We do make use of multiple protocols in LAM. TCP connections are used for
> > all communications between MPI processes if the tcp rpi is selected (which
> > is the default). There are other rpi's which can be used for inter-process
> > communication which include crtcp, lamd, sysv, usysv and gm. UDP is used
> > for out of band communication. For more information, please see the user's
> > documentation at www.lam-mpi.org/using/docs.
> >
> > Hope this helps,
> > Anju
> >
> >
> > On Thu, 17 Jun 2004, Muhlis Akdag wrote:
> >
> > > Hello
> > >
> > > I know there are many posts with the topic transport protocoll in lam
> mpi...but here my question
> > >
> > > i read that lam mpi use udp to transport informations between
> nodes...but i also read that a tcp socket create it from lambootagent...
> > > so my question:
> > >
> > > what are transport with udp and what is transport with tcp...
> > >
> > > i test a code with 2 nodes...a send and a receive:
> > >
> > > #include <stdio.h>
> > > #include <mpi.h>
> > > #include <math.h>
> > >
> > > #define WORLD MPI_COMM_WORLD
> > >
> > > int main(int argc, char *argv[]){
> > >
> > > int rank, size, i;
> > >
> > > MPI_Init( &argc, &argv);
> > > MPI_Comm_rank(MPI_COMM_WORLD, &rank);
> > > MPI_Comm_size(MPI_COMM_WORLD, &size);
> > >
> > >
> > > int l=1;
> > > int sendarray[l];
> > > int recvarray[l];
> > >
> > >
> > >
> > > if (rank==0){
> > > for (i=0; i<l; i++){
> > > sendarray[i] = i;
> > > }
> > > printf("proc %d: sendarray[%d] = %d\n", rank, l-1, sendarray[l-1]);
> > >
> > > MPI_Send( sendarray, l, MPI_INT, 1, 123, WORLD);
> > > }
> > > else if (rank==1){
> > > MPI_Status status_recv;
> > > MPI_Recv( recvarray, l, MPI_INT,0, 123, WORLD, &status_recv);
> > >
> > > printf("proc %d received : recvarray[%d] = %d\n", rank, l-1,
> recvarray[l-1]);
> > > }
> > >
> > > MPI_Finalize();
> > >
> > > return 0;
> > > }
> > >
> > > than i trace ist with ethereal a network sniffer...i have many udp
> packets between node a and b and also tcp packets...but what are transport
> with what?
> > >
> > > a second question is...when use lam mpi ssh and rsh...is this right
> when i say: only in lamboot to hboot the other nodes? with mpirun both
> configuration are the same?
> > >
> > > i hope some people can help me and understand my confuse english :)
> > >
> > >
> > >
> > >
> > _______________________________________________
> > This list is archived at http://www.lam-mpi.org/MailArchives/lam/
> >
>
> _______________________________________________
> This list is archived at http://www.lam-mpi.org/MailArchives/lam/
>
|
