[R-SIG-Mac] snow cluster - unable to open connection

Sean Davis sdavis2 at mail.nih.gov
Tue Sep 5 01:31:10 CEST 2006

Martin Renner wrote:
> I'm trying to build a sock cluster using snow but have difficulties  
> to include more than one machine. In the terminal, password-less ssh  
> is working on all machines and each machine can talk to itself (cl <-  
> makeSOCKcluster ("localhost") works). Trying to cluster more than one  
> machine, I get:
> Error in socketConnection (port = port, server = TRUE, blocking =  
> TRUE,  :
> 	unable to open connection
> In addition: warning message:
> port 600011 cannot be opened
> I've tried to disable the firewalls as well as including "port = 22":
> cl <- makeSOCKcluster (c("localhost", "localhost", "machine2.local",  
> "machine2.local"), port = 22)
> but this fails just as well.
> My set-up is as follows:
> R version: 2.3.1
> Mac OS versions: 10.3.9 (on dual G4 and G5 iMac), 10.4.7 (MacBook Pro)
> Has anybody else encountered this problem? I've searched the usual  
> sites with no luck. Any pointers would be much appreciated.
I haven't tried to make a socket-based cluster, but I have successfully 
made a lam-mpi-based cluster.  I ended up having to TURN OFF the 
firewall, as at least for MPI, the ports are assigned randomly, so 
knowing which is going to be assigned is not possible, I don't think, 
and I think that each process gets a separate port, if I remember 
correctly (but I could definitely be wrong).  In any case, lam-mpi 
installed "out-of-the-box" on my Mac Pro as well as on a G5 and an 
Xserver with XTools installed, so you could give that a try, as well.

As for the more immediate problem, does running with just one machine in 
the cluster work?  If so, does using multiple "machines" on localhost 
work?  How about turning off the firewalls to the two machines--does 
that make a difference (don't do this if you don't think it is safe, 


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