如何阻止R离开僵尸进程

本文介绍了如何阻止R离开僵尸进程的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 29岁程序员，3月因学历无情被辞！ library（doMC） library（doParallel） registerDoMC（4） timing< - system.time（fitall print（i）}） 我启动 R 和看看进程表： >系统（ps -efl） F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD 4 S chbr 1 0 5 80 0 - 21399 wait 10:58？ 00:00:00 / usr / local / lib / R / bin / exec / R --no-save --no-restore 0 S chbr 9 1 0 80 0 - 1113 wait 10:58？ 00:00:00 sh -c ps -efl 0 R chbr 10 9 0 80 0 - 4294 - 10:58？ 00:00:00 ps -efl 如果我使用上面提到的简单循环 doMC 或 doParallel 在后面留下一个僵尸进程。输出 ps -efl 运行循环后： >系统（ps -efl） F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD 4 S chbr 1 0 4 80 0 - 25256 wait 11:00？ 00:00:00 / usr / local / lib / R / b 1 Z chbr 10 1 0 80 0 - 0 exit 11:00？ 00:00:00 [R]< defunct> 0 S chbr 12 1 0 80 0 - 1113等待11:00？ 00:00:00 sh -c ps -efl 0 R chbr 13 12 0 80 0 - 4294 - 11:00？ 00:00:00 ps -efl 如果我不重复 registerDoMC（4）再次没有额外的僵尸进程被创建。但是，如果我发行 registerDoMC（4），则会创建一个额外的僵尸进程： >系统（ps -efl） F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD 4 S chbr 1 0 0 80 0 - 25554等待11:00？ 00:00:01 / usr / local / lib / R / b 1 Z chbr 21 1 0 80 0 - 0 exit 11:02？ 00:00:00 [R]< defunct> 1 z chbr 22 1 0 80 0 - 0 exit 11:02？ 00:00:00 [R]< defunct> 0 S chbr 26 1 0 80 0 - 1113等待11:03？ 00:00:00 sh -c ps -efl 0 R chbr 27 26 0 80 0 - 4294 - 11:03？ 00:00:00 ps -efl 这就是我认为它可以是 doMC 这是做不应该做的事情。如果doMC造成这种情况，有没有办法阻止 doMC 离开僵尸进程？ （ stopCluster（）不起作用，因为没有创建群集。） > sessionInfo（） R开发中（unstable）（2014-08-16 r66404）平台：x86_64-unknown-linux-gnu（64位） 语言环境：$ LC_CTYPE = en_IE.UTF-8 LC_NUMERIC = C [3] LC_TIME = en_IE.UTF-8 LC_COLLATE = en_IE.UTF-8 [5] LC_MONETARY = en_IE.UTF- LC_MESSAGES = en_IE.UTF-8 [7] LC_PAPER = en_IE.UTF-8 LC_NAME = C [9] LC_ADDRESS = C LC_TELEPHONE = C [11] LC_MEASUREMENT = en_IE.UTF -8 LC_IDENTIFICATION = C 附加的基本软件包： [1] parallel stats graphics grDevices utils数据集方法 [8] base 其他附加软件包： [1] doParallel_1.0.8 doMC_1.3.3 iterators_1.0.7 foreach_1.4.2 通过命名空间加载（而不是附加）： [1] codetools_0.2-8 compiler_3.2.0 解决方案这与foreach无关或者doMC;正如Steve Weston在回答其他StackOverflow查询时指出的那样，doMC基本上只是mclapply的一个包装，你可以看到通过对mclapply的简单调用创建的僵尸进程： mclapply（rep（5,4），rnorm） 在我的系统中，这会留下两个僵尸进程： [richcalaway @ richcalaway-pc〜] $ ps -efl | grep defunct 1 Z 1660945517 28701 28624 0 77 0 - 0出口12:00 pts / 1 00:00:00 [R]< defunct> 1 Z 1660945517 28702 28624 0 78 0 - 0出口12:00 pts / 1 00:00:00 [r] 0 S 1660945517 28704 28308 0 78 0 - 15306 pipe_w 12:00 pts / 2 00:00:00 grep defunct 在正常情况下，这些僵尸进程不会造成任何麻烦，并且在R会话结束时会消失。您可以通过使用doParallel和一个fork群集来避免它们，而不是使用doMC。 干杯， 首席项目经理 革命分析 Here is a little reproducible example:library(doMC)library(doParallel)registerDoMC(4) timing <- system.time( fitall <- foreach(i=1:1000, .combine = "c") %dopar% { print(i) })I start up R and look at the process table:> system("ps -efl")F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD4 S chbr 1 0 5 80 0 - 21399 wait 10:58 ? 00:00:00 /usr/local/lib/R/bin/exec/R --no-save --no-restore0 S chbr 9 1 0 80 0 - 1113 wait 10:58 ? 00:00:00 sh -c ps -efl0 R chbr 10 9 0 80 0 - 4294 - 10:58 ? 00:00:00 ps -eflIf I use the aformentioned simple for loop doMC or doParallel leave a zombie process behind. Output of ps -efl after running the loop:> system("ps -efl")F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD4 S chbr 1 0 4 80 0 - 25256 wait 11:00 ? 00:00:00 /usr/local/lib/R/b1 Z chbr 10 1 0 80 0 - 0 exit 11:00 ? 00:00:00 [R] <defunct>0 S chbr 12 1 0 80 0 - 1113 wait 11:00 ? 00:00:00 sh -c ps -efl0 R chbr 13 12 0 80 0 - 4294 - 11:00 ? 00:00:00 ps -eflIf I repeat the loop without issuing registerDoMC(4) again no additional zombie process gets created. However, if I issue registerDoMC(4) an additional zombie process gets created:> system("ps -efl")F S UID PID PPID C PRI NI ADDR SZ WCHAN STIME TTY TIME CMD4 S chbr 1 0 0 80 0 - 25554 wait 11:00 ? 00:00:01 /usr/local/lib/R/b1 Z chbr 21 1 0 80 0 - 0 exit 11:02 ? 00:00:00 [R] <defunct>1 Z chbr 22 1 0 80 0 - 0 exit 11:02 ? 00:00:00 [R] <defunct>0 S chbr 26 1 0 80 0 - 1113 wait 11:03 ? 00:00:00 sh -c ps -efl0 R chbr 27 26 0 80 0 - 4294 - 11:03 ? 00:00:00 ps -eflThat's how I figured it could be doMC which is doing something that should not be done. If doMC is causing this is there a way to stop doMC from leaving zombie processes behind? (stopCluster() does not work as no cluster gets created in the first place.)> sessionInfo()R Under development (unstable) (2014-08-16 r66404)Platform: x86_64-unknown-linux-gnu (64-bit)locale: [1] LC_CTYPE=en_IE.UTF-8 LC_NUMERIC=C [3] LC_TIME=en_IE.UTF-8 LC_COLLATE=en_IE.UTF-8 [5] LC_MONETARY=en_IE.UTF-8 LC_MESSAGES=en_IE.UTF-8 [7] LC_PAPER=en_IE.UTF-8 LC_NAME=C [9] LC_ADDRESS=C LC_TELEPHONE=C[11] LC_MEASUREMENT=en_IE.UTF-8 LC_IDENTIFICATION=Cattached base packages:[1] parallel stats graphics grDevices utils datasets methods[8] baseother attached packages:[1] doParallel_1.0.8 doMC_1.3.3 iterators_1.0.7 foreach_1.4.2loaded via a namespace (and not attached):[1] codetools_0.2-8 compiler_3.2.0 解决方案 This really has nothing to do with foreach or doMC; as Steve Weston has pointed out in answer to other StackOverflow queries, doMC is essentially just a wrapper for mclapply, and you can see zombie processes created with a simple call to mclapply:library(parallel)mclapply(rep(5,4), rnorm)On my system, this leaves two zombie processes:[richcalaway@richcalaway-pc ~]$ ps -efl | grep defunct1 Z 1660945517 28701 28624 0 77 0 - 0 exit 12:00 pts/1 00:00:00 [R] <defunct>1 Z 1660945517 28702 28624 0 78 0 - 0 exit 12:00 pts/1 00:00:00 [R] <defunct>0 S 1660945517 28704 28308 0 78 0 - 15306 pipe_w 12:00 pts/2 00:00:00 grep defunctUnder normal circumstances, these zombie processes won't cause any trouble, and they do disappear when the R session ends. You can avoid them by using doParallel and a fork cluster instead of using doMC.Cheers,Rich CalawayPrincipal Program ManagerRevolution Analytics 这篇关于如何阻止R离开僵尸进程的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！