Any help of this would be greatly appreciated.
I have the following R code (following tutorial at https://www.r-bloggers.com/parallel-r-loops-for-windows-and-linux/) to carry out 233 mutually exclusive calculations in parallel. There are 4 cores and 32 GB of RAM on the machine where this code is executing.
# Calculate the number of cores
no_cores <- detectCores() - 1
# initiate cluster
cl <- makeCluster(no_cores)
registerDoSNOW(cl)
# Process sandboxes in parallel - there are 233 sandboxes in total
foreach (j=1:nrow(sandboxes), .packages=c("dplyr", "rJava", "RJDBC", "lazyeval", "caTools", "stringr", "readxl")) %dopar%
{
print("Execution is in foreach block now")
// Do stuff
}
stopCluster(cl)
I am getting the error message even before the execution starts inside the foreach loop.
Error in { :
task 3 failed - "RcallMethod: attempt to call a method of a NULL object."
Here is the output from sessionInfo()
R version 3.3.3 (2017-03-06)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 7 x64 (build 7601) Service Pack 1
locale:
[1] LC_COLLATE=English_United States.1252 LC_CTYPE=English_United States.1252 LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C LC_TIME=English_United States.1252
attached base packages:
[1] parallel stats graphics grDevices utils datasets methods base
other attached packages:
[1] doSNOW_1.0.14 snow_0.4-2 doParallel_1.0.10 iterators_1.0.8 foreach_1.4.3 readxl_0.1.1 stringr_1.2.0 caTools_1.17.1
[9] lazyeval_0.2.0 RJDBC_0.2-5 DBI_0.6-1 rJava_0.9-8 dplyr_0.5.0
loaded via a namespace (and not attached):
[1] Rcpp_0.12.10 codetools_0.2-15 assertthat_0.1 bitops_1.0-6 R6_2.2.0 magrittr_1.5 stringi_1.1.3 tools_3.3.3
[9] compiler_3.3.3 tibble_1.3.0