title: Results of workers not returned properly - snow - debug
body: <p>I'm using the <code>snow</code> package in R to execute a function on a <code>SOCK</code> cluster with multiple machines(3) running on Linux OS. I tried to run the code with both <code>parLapply</code> and <code>clusterApply</code>. </p>
  
  <p>In case of any error at the worker level, the results of the worker nodes are not returned properly to master making it very hard to debug. I'm currently logging every heartbeat of the worker nodes independently using <code>futile.logger</code>. It seems as if the results are properly computed. But when I tried to print the result at the master node (After receiving the output from workers) I get an error which says, <code>Error in checkForRemoteErrors(val): 8 nodes produced errors; first error: missing value where TRUE/FALSE needed</code>.  </p>
  
  <p>Is there any way to debug the results of the workers more deeply? </p>