Greetings,

I am having an interesting problem and I wonder if anyone else has 
seen this behavior.

I am running R 2.11.1 with SNOW 0.3-3 on a Dell cluster running CentOS 5.5.

I create my cluster using:
cluster<- makeCluster(nodes,type="SOCK",port=10191)     # nodes is a 
vector of compute nodes

I then wrap a loop around clusterApplyLB to evaluate my function 
multiple times, with different parameters, without recreating the 
cluster every time. The following code segment shows what I am trying to do:


for (j in loopstart:loopend)
{

call.m=list(
           step1=T,
           dat=x.m[,c(1:7, j)]       # x.m is data from a csv file 
read into a table
            )

clusterApplyLB(cluster,c(10:100),test.each.term,call=call.m)

}

stopCluster(cluster)


The problem that I am having is that sometimes it will run for  50 
iterations of this loop then crash. Sometimes 15 iterations, 
sometimes 2. When the crash happens, I receive the following error 
message every time:

Error in checkForRemoteErrors(val) :
   one node produced an error: cannot open the connection
Calls: clusterApplyLB -> dynamicClusterApply -> checkForRemoteErrors
Execution halted


Any ideas as to what might be going on? I have run this code 
successfully many times when I do not use the loop. I have a lot of 
data to process and recreating the cluster every time that I want to 
run my function is a waste of time.

Thanx,

Ken


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