search for: mc_ret

...stance launched from the same AMI (no updates installed after launch) and processed thousands of different input data sets successfully. I now have an input dataset for which I face the following bug: The basic outline of the problematic section of the script: # parts is a data.table with 88 rows mc_ret <- parallel::mclapply(sample.int(nrow(parts)), function(i) { # do some data wrangling and write the result to a file # ... print(paste0("part ", i, " written successfully.")) return(TRUE) }, mc.preschedule = FALSE, mc.cores = 2L) str(mc_ret) Expected output: &quot...

...es installed after launch) and processed thousands of different input data sets successfully. I now have an input dataset for which I face the following bug: >> >> The basic outline of the problematic section of the script: >> >> # parts is a data.table with 88 rows >> mc_ret <- parallel::mclapply(sample.int(nrow(parts)), function(i) { >> # do some data wrangling and write the result to a file >> # ... >> >> print(paste0("part ", i, " written successfully.")) >> return(TRUE) >> }, mc.preschedule = FA...

...same AMI (no updates installed after launch) and processed thousands of different input data sets successfully. I now have an input dataset for which I face the following bug: > > The basic outline of the problematic section of the script: > > # parts is a data.table with 88 rows > mc_ret <- parallel::mclapply(sample.int(nrow(parts)), function(i) { > # do some data wrangling and write the result to a file > # ... > > print(paste0("part ", i, " written successfully.")) > return(TRUE) > }, mc.preschedule = FALSE, mc.cores = 2L) > &...

...o experienced in debugging these kinds of issues. Anyway, I gave it a try and I think I have found the immediate cause: I installed the debug symbols (r-base-core-dbg), placed https://github.com/wch/r-source/blob/tags/R-3-5-2/src/library/parallel/src/fork.c in cwd and changed the wrapper code to: mc_ret <- parallel::mclapply(seq_len(nrow(parts)), function(i) { # we fail for the input resulting in parts having 85 rows if (nrow(parts) == 85L && !file.exists(as.character(Sys.getpid()))) { file.create(as.character(Sys.getpid())) print(Sys.getpid()) Sys.sleep(30)...

...ebugging these kinds of issues. Anyway, I gave it a try and I think I have found the immediate cause: > > I installed the debug symbols (r-base-core-dbg), placed https://github.com/wch/r-source/blob/tags/R-3-5-2/src/library/parallel/src/fork.c in cwd and changed the wrapper code to: > > mc_ret <- parallel::mclapply(seq_len(nrow(parts)), function(i) { > # we fail for the input resulting in parts having 85 rows > if (nrow(parts) == 85L && !file.exists(as.character(Sys.getpid()))) { > file.create(as.character(Sys.getpid())) > print(Sys.getpid()...

...ink I have found the immediate c= >> ause: >>> >>> I installed the debug symbols (r-base-core-dbg), placed https://github.= >> com/wch/r-source/blob/tags/R-3-5-2/src/library/parallel/src/fork.c in cwd= >> and changed the wrapper code to: >>> >>> mc_ret <- parallel::mclapply(seq_len(nrow(parts)), function(i) { >>> # we fail for the input resulting in parts having 85 rows >>> if (nrow(parts) =3D=3D 85L && !file.exists(as.character(Sys.getpid= >> ()))) { >>> file.create(as.character(Sys.ge...

...ink I have found the immediate c= >> ause: >>> >>> I installed the debug symbols (r-base-core-dbg), placed https://github.= >> com/wch/r-source/blob/tags/R-3-5-2/src/library/parallel/src/fork.c in cwd= >> and changed the wrapper code to: >>> >>> mc_ret <- parallel::mclapply(seq_len(nrow(parts)), function(i) { >>> # we fail for the input resulting in parts having 85 rows >>> if (nrow(parts) =3D=3D 85L && !file.exists(as.character(Sys.getpid= >> ()))) { >>> file.create(as.character(Sys.ge...