「在運行最大作業數」不等於在遠程服務器上使用GNU Parallel時指定的作業數量？

Question

我試圖在PBS集羣上運行GNU Parallel的許多小型串行作業，每個計算節點有16個核心，因爲我打算使用多個計算節點，因此我將選項-S $ SERVERNAME傳遞給GNUParallel，但是讓我困惑的是是使用-S $SERVERNAME不等於我指定的就業人數時，我打算產卵超過9個工作啓動的節點上作業的數量，下面是我的意見：

[fchen14@shelob001 ~]$ parallel --version 
GNU parallel 20160922 
Copyright (C) 2007,2008,2009,2010,2011,2012,2013,2014,2015,2016 
Ole Tange and Free Software Foundation, Inc. 
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> 
This is free software: you are free to change and redistribute it. 
GNU parallel comes with no warranty. 

Web site: http://www.gnu.org/software/parallel 

When using programs that use GNU Parallel to process data for publication 
please cite as described in 'parallel --citation'. 
[fchen14@shelob001 ~]$ hostname # this shows my hostname 
shelob001 

使用時GNUParallel作爲本地主機沒有-SERVERNAME，沒有問題，我打算派生10個工作，並且GNUParallel開始了10個工作：

[fchen14@shelob001 ~]$ parallel --progress echo ::: `seq 1 10` 

Computers/CPU cores/Max jobs to run 
1:local/16/10 # 10 jobs spawned, no problem 

Computer:jobs running/jobs completed/%of started jobs/Average seconds to complete 
local:10/0/100%/0.0s 1 
local:9/1/100%/0.0s 2 
local:8/2/100%/0.0s 3 
local:7/3/100%/0.0s 4 
local:6/4/100%/0.0s 5 
local:5/5/100%/0.0s 6 
local:4/6/100%/0.0s 7 
local:3/7/100%/0.0s 8 
local:2/8/100%/0.0s 9 
local:1/9/100%/0.0s 10 
local:0/10/100%/0.0s 

當我使用GNUParallel來使用-S $SERVERNAME產生少於10個作業時，仍然沒有問題。

[fchen14@shelob001 ~]$ parallel -S shelob001 --progress echo ::: `seq 1 1` 

Computers/CPU cores/Max jobs to run 
1:shelob001/16/1 # When the number of jobs is less than 10, no problem 

Computer:jobs running/jobs completed/%of started jobs/Average seconds to complete 
shelob001:1/0/100%/0.0s 1 
shelob001:0/1/100%/1.0s 

[fchen14@shelob001 ~]$ parallel -S shelob001 --progress echo ::: `seq 1 8` 

Computers/CPU cores/Max jobs to run 
1:shelob001/16/8 # When the number of jobs is less than 10, no problem 

Computer:jobs running/jobs completed/%of started jobs/Average seconds to complete 
shelob001:8/0/100%/0.0s 1 
shelob001:7/1/100%/1.0s 7 
shelob001:6/2/100%/0.5s 3 
shelob001:5/3/100%/0.3s 8 
shelob001:4/4/100%/0.2s 5 
shelob001:3/5/100%/0.2s 2 
shelob001:2/6/100%/0.2s 6 
shelob001:1/7/100%/0.1s 4 
shelob001:0/8/100%/0.1s 

[fchen14@shelob001 ~]$ parallel -S shelob001 --progress echo ::: `seq 1 9` 

Computers/CPU cores/Max jobs to run 
1:shelob001/16/9 # When the number of jobs is less than 10, no problem 

Computer:jobs running/jobs completed/%of started jobs/Average seconds to complete 
shelob001:9/0/100%/0.0s 1 
shelob001:8/1/100%/1.0s 5 
shelob001:7/2/100%/0.5s 8 
shelob001:6/3/100%/0.3s 2 
shelob001:5/4/100%/0.2s 6 
shelob001:4/5/100%/0.2s 9 
shelob001:3/6/100%/0.2s 3 
shelob001:2/7/100%/0.1s 4 
shelob001:1/8/100%/0.1s 7 
shelob001:0/9/100%/0.1s 

這裏是混淆了我，當我嘗試使用作業號> = 10，就業人數產生了比想總是少了一個，在這裏我要產卵10，纔開始9個作業：

[fchen14@shelob001 ~]$ parallel -S shelob001 --progress echo ::: `seq 1 10` # I want to start 10 jobs 

Computers/CPU cores/Max jobs to run 
1:shelob001/16/9 #why here "Max jobs to run" is 9? 

Computer:jobs running/jobs completed/%of started jobs/Average seconds to complete 
shelob001:9/0/100%/0.0s 2 
shelob001:9/1/100%/3.0s 1 
shelob001:8/2/100%/1.5s 7 
shelob001:7/3/100%/1.0s 4 
shelob001:6/4/100%/0.8s 9 
shelob001:5/5/100%/0.6s 8 
shelob001:4/6/100%/0.5s 3 
shelob001:3/7/100%/0.4s 5 
shelob001:2/8/100%/0.4s 6 
shelob001:1/9/100%/0.4s 10 
shelob001:0/10/100%/0.4s 

[fchen14@shelob001 ~]$ parallel -S shelob001 --progress echo ::: `seq 1 11` 

Computers/CPU cores/Max jobs to run 
1:shelob001/16/10 # it seems the jobs started is one less than I specified 

Computer:jobs running/jobs completed/%of started jobs/Average seconds to complete 
shelob001:10/0/100%/0.0s 1 
shelob001:10/1/100%/3.0s 2 
shelob001:9/2/100%/1.5s 8 
shelob001:8/3/100%/1.0s 3 
shelob001:7/4/100%/0.8s 4 
shelob001:6/5/100%/0.6s 5 
shelob001:5/6/100%/0.5s 7 
shelob001:4/7/100%/0.4s 10 
shelob001:3/8/100%/0.4s 9 
shelob001:2/9/100%/0.3s 6 
shelob001:1/10/100%/0.4s 11 
shelob001:0/11/100%/0.4s 
[fchen14@shelob001 ~]$ 

我使用「top」檢查了計算節點的狀態，但它表明只有9個Cpus在我使用seq 1 10時使用。希望我已經明確了我的問題，有誰能指出這個問題的可能原因？任何建議都是值得歡迎的。

非常感謝！

Answer 1

看起來像你發現了一個錯誤。解決方法：-j + 1