[R-sig-hpc] snow, socket cluster: problem with path to rscript

[Dirk Eddelbuettel]

On 15 April 2009 at 17:29, Matthieu Stigler wrote:
| >> So it is now working for the local computer with. However, when trying to
| >> use the external computer, it seems to be working but nothing happens after
| >> he asked for the last password...
| >>     
| >
| > This tells you is that "something went wrong".  The basic strategy in this case
| > is to use the "outfile" option to hopefully capture an error message.  You might
| > need to set outfile differently for different slaves, particularly if
| > you're starting
| > more than one on the same machine, but I suggest just starting one slave
| > on 210 to avoid the issue.  So do something like:
| >
| >   
| >> host210 <- list(host = "mat at 192.100.100.210", rscript = "/usr/bin/Rscript",
| >>     
| > +                       outfile="/tmp/log.txt")
| >   
| >> cl2 <- makeCluster(list(host210), type = "SOCK")
| >>     
| >
| >   
| Ok, thanks for pointing out this methid.
| 
|  I tried it and got following error message. This does not seem not be 
| computer specific (tried to do it to other host 213, and from other host 
| 213 to 212, always same error message):
| 
| starting worker for ubuntu:10187 
| 
| Error in socketConnection(master, port = port, blocking = TRUE, open = "a+b") : 
| 
|   unable to open connection
| 
| Calls: local ... slaveLoop -> recvData -> makeSOCKmaster -> socketConnection
| 
| In addition: Warning message:
| 
| In socketConnection(master, port = port, blocking = TRUE, open = "a+b") :
| 
|   ubuntu:10187 cannot be opened
| 
| Execution halted
| 
| 
| Is it related to ssh or snow? I did not find any reference to that prob 
| googling for it...

Test for it --- can you actually issue an ssh command for the _script_ on the
_machine_ you have specified ?  I.e. run

$ ssh mat at 192.100.100.210 /usr/bin/Rscript --version

where I added --version to make sure Rscript has something to do.  Unless
this works 'by itself', you cannot expect to use it. 

Dirk

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