Could it be connected with the fact that each R session creates an Rtmp<smth> directory in tmp (at least on UNIX-alike) and that if started simultaneously on machines with the same time stamp they might want to use a directory with the same <smth>? It still does not explain the behaviour much as, first, loading a package (with a shared object and external dependencies) does not seem to cause creation of any files there, and, second, I have never experienced such problems of our Linux farm although there were situations where I launched about a hundred of R session on a farm at the same time. Maybe the external library itself uses this temp space and locks it?
Oleg Vadim Organovich wrote: > Hi, > > I am debugging intermittent crashes of R that seem to happen when multiple R > sessions nearly summaltaneously load same dll-based library. > > I have R and my libraries installed on a network drive (everything is > Windows). The drive is visible from a farm of servers. I have an R script, > foo.R, that just loads a dll-based library (to be precise it loads a library > that requires a dll-based library). When I start R (via Rscript --vanilla > foo.R) from all of the farm computers summaltaneously some of the sessions > often crash. It doesn't seem to be specific to the library, I was able to > reproduce this with the gbm library as well as with my own library. It feels > that the longer it takes to load the library the higher the probability of > the crash. > > foo.R : > library(vmisc) > > The most informative error message I've got so far looks like this, here > vmisc dll is the required library that dynamically loads a dll. > > Loading required package: vmiscdll > Error in file(file, "r") : unable to open connection > In addition: Warning message: > In file(file, "r") : > cannot open file 'q:/R/vogranovich/library/vmisc/R/vmisc', reason > 'Permission denied' > Error : unable to load R code in package 'vmisc' > Error: package/namespace load failed for 'vmisc' > Execution halted > Exit Code 1 - Process forcefully killed by the TestMaster > In stand alone sessions, interactive or not, everything loads fine. > > Does loading a library place some sort of a lock? > > I would appreciate any help with this matter. > > Regards, > Vadim > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel -- Dr Oleg Sklyar * EBI-EMBL, Cambridge CB10 1SD, UK * +44-1223-494466 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
