Parallel seems to be installed properly as I am able to run basic parallel check commands.
# parallel --version
GNU parallel 20161222
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'.
But when I'm trying to execute a query on remote servers it doesn't give any output also doesn't returns the prompt.. eg :-
parallel ssh {} hostname :::: hosts
Academic tradition requires you to cite works you base your article on.
When using programs that use GNU Parallel to process data for publication
please cite:
O. Tange (2011): GNU Parallel - The Command-Line Power Tool,
;login: The USENIX Magazine, February 2011:42-47.
This helps funding further development; AND IT WON'T COST YOU A CENT.
If you pay 10000 EUR you should feel free to use GNU Parallel without citing.
To silence this citation notice: run 'parallel --citation'.
in above eg , hosts file contains a list of remote server IP's
Even a simple parallel echo ::: A B C command doens's gives output..
I tried running with /usr/bin/parallel but issue remains..
when I ran the command using bash -x I get the following error :-
bash -x parallel ssh {} hostname :::: hosts
+ use IPC::Open3
/usr/bin/parallel: line 22: use: command not found
/usr/bin/parallel: parallel: line 24: syntax error near unexpected token `('
/usr/bin/parallel: parallel: line 24: `use POSIX qw(:sys_wait_h setsid ceil :errno_h);'
I've checked the file /usr/bin/parallel seems fine to me.
Not able to find solution for this. Any help is really appreciated.
Thanks.
UPDATE_1 :-
root#sg-server:[~]:# parallel -Dall echo ::: 1
shell? perl /usr/bin/parallel -Dall echo ::: 1
shell? -bash
which -bash => shell path /bin/bash
Academic tradition requires you to cite works you base your article on.
When using programs that use GNU Parallel to process data for publication
please cite:
O. Tange (2011): GNU Parallel - The Command-Line Power Tool,
;login: The USENIX Magazine, February 2011:42-47.
This helps funding further development; AND IT WON'T COST YOU A CENT.
If you pay 10000 EUR you should feel free to use GNU Parallel without citing.
To silence this citation notice: run 'parallel --citation'.
Open file descriptors: 2 1
echo Context: Non: 4 Ctxgrp: NonCtxGrp: 1
echo ▒<▒> Context: Non: 4 Ctxgrp: 1 NonCtxGrp: 1
Wanted procs: 16
MultifileQueue->empty RecordQueue->empty CommandLineQueue->empty JobQueue->empty MultifileQueue->empty RecordQueue->empty eval 1
noncontext + command: 5
context+noncontext + command: 5
cmd_line->number_of_args 1
Replace echo ▒<▒>
Target: echoTarget: ▒<▒>Replacing in ▒<▒>
Return echo 1
noncontext + command: 5
context+noncontext + command: 5
noncontext + command: 5
context+noncontext + command: 5
6 == 6 echo 1
Time to fork 1 procs: 0 (processes so far: 1)
MultifileQueue->empty 1 RecordQueue->empty 1CommandLineQueue->empty 1JobQueue->empty 1 RecordQueue-unget ''
JobQueue->empty Limited to procs: 1
JobQueue->empty Running jobs before on ::
: has out of 1 jobs running. Start another.
JobQueue->empty Command to run on ':': 'echo 1'
processes . Starting (1): echo 1
bash -c testfun\(\)\ \{\ rm\ /tmp/parTMasE.tst\;\ \}\;\ export\ -f\ testfun\;\ perl\ -MIPC::Open3\ -e\ if\\\(\\\$pid\\\=::open3\\\(\\\$i,\\\$o,\\\$e,\\\"-\\\"\\\)\\\)\\\ \\\{\\\ wait\\\;\\\ \\\}\\\ else\\\ \\\{\\\ exec\\\(\\\"bash\\\",\\\"-c\\\",\\\"testfun\\\ \\\&\\\&\\\ true\\\"\\\)\\\;\\\ \\\} 2>/dev/null
^Ckill_sleep TERM
kill_sleep TERM
kill_sleep TERM
kill_sleep KILL
Even on running parallel -Dall echo ::: 1 command, I had to CTRL+c to get the prompt back.
As we debugged in the comments your (/usr/local)/bin/rm is not the normal (/usr/local)/bin/rm.
On my ubuntu 14.04 (Linux 3.19.0 64bit) PC, I ran a perl program that has the following in a loop
$params = setupParams();
$ret = `SOME_CMD $params`;
...
But for some reason, SOME_CMD sometimes gaves Segmentation fault (core dumped) occasionally. In order to figure out the cause of the core dump, I need to get the core file.
Unfortunately I tried ulimit -S -c 0 on the terminal where I ran the perl script, but it didn't produce a core file.
Any ideas would be appreciated.
ulimit -c 0 prevents core files to be written. You need to use
ulimit -c unlimited
Btw: you should upgrade to a maintained OS.
I have tried may things but I can get my program to generate core dump when it crashes.
$ ulimit -c
200000000
The limit seems ok.
$ cat /proc/sys/fs/suid_dumpable
2
The pattern looks ok.
$ cat /proc/sys/kernel/core_pattern
/tmp/core_%e
When I kill -SIGSEGV I get a core dump. The process has very little memory. Why is there no core dump file?
I have a print at the end of main that i don't see and I'm running the program in bash while loop with sleep 2;
The os is Ubuntu 12.04LTS
Is there a way to know where command typed? I mean when I list the running processes, there are many processes with full path name, but it does not indicated where these process started.
Think about that there is a java application under /tmp/AppJava.jar It could be executed under /home/appuser or /home/test by manullay or other script.
Is there a way how to find java -jar /tmp/AppJava.jar executed under which directory?
Yes you can.
You need to find the PID of the process, and then
ls -l /proc/$PID/cwd
For example, my shell has current directory /home/igor:
$ ls -l /proc/$$/cwd
lrwxrwxrwx 1 igor igor 0 nov 11 21:49 /proc/6569/cwd -> /home/igor
The PID of the process you can find using ps:
$ ps aux | grep java.*AppJava.jar
I would like to monitor the number of threads used by a specific process on Linux.
Is there an easy way to get this information without impacting the performance of the process?
try
ps huH p <PID_OF_U_PROCESS> | wc -l
or htop
To get the number of threads for a given pid:
$ ps -o nlwp <pid>
Where nlwp stands for Number of Light Weight Processes (threads). Thus ps aliases nlwp to thcount, which means that
$ ps -o thcount <pid>
does also work.
If you want to monitor the thread count, simply use watch:
$ watch ps -o thcount <pid>
To get the sum of all threads running in the system:
$ ps -eo nlwp | tail -n +2 | awk '{ num_threads += $1 } END { print num_threads }'
Each thread in a process creates a directory under /proc/<pid>/task. Count the number of directories, and you have the number of threads.
cat /proc/<PROCESS_PID>/status | grep Threads
ps -eLf on the shell shall give you a list of all the threads and processes currently running on the system.
Or, you can run top command then hit 'H' to toggle thread listings.
$ ps H p pid-id
H - Lists all the individual threads in a process
or
$cat /proc/pid-id/status
pid-id is the Process ID
eg.. (Truncated the below output)
root#abc:~# cat /proc/8443/status
Name: abcdd
State: S (sleeping)
Tgid: 8443
VmSwap: 0 kB
Threads: 4
SigQ: 0/256556
SigPnd: 0000000000000000
If you use:
ps uH p <PID_OF_U_PROCESS> | wc -l
You have to subtract 1 to the result, as one of the lines "wc" is counting is the headers of the "ps" command.
My answer is more gui, but still within terminal. Htop may be used with a bit of setup.
Start htop.
Enter setup menu by pressing F2.
From leftmost column choose "Columns"
From rightmost column choose the column to be added to main monitoring output, "NLWP" is what you are looking for.
Press F10.
JStack is quite inexpensive - one option would be to pipe the output through grep to find active threads and then pipe through wc -l.
More graphically is JConsole, which displays the thread count for a given process.
Here is one command that displays the number of threads of a given process :
ps -L -o pid= -p <pid> | wc -l
Unlike the other ps based answers, there is here no need to substract 1 from its output as there is no ps header line thanks to the -o pid=option.
Newer JDK distributions ship with JConsole and VisualVM. Both are fantastic tools for getting the dirty details from a running Java process. If you have to do this programmatically, investigate JMX.
If you're looking for thread count for multiple processes, the other answers won't work well for you, since you won't see the process names or PIDs, which makes them rather useless. Use this instead:
ps -o pid,nlwp,args -p <pid_1> <pid_2> ... <pid_N>
In order to watch the changes live, just add watch:
watch ps -o pid,nlwp,args -p <pid_1> <pid_2> ... <pid_N>
jvmtop can show the current jvm thread count beside other metrics.
The easiest way is using "htop". You can install "htop" (a fancier version of top) which will show you all your cores, process and memory usage.
Press "Shift+H" to show all process or press again to hide it.
Press "F4" key to search your process name.
Installing on Ubuntu or Debian:
sudo apt-get install htop
Installing on Redhat or CentOS:
yum install htop
dnf install htop [On Fedora 22+ releases]
If you want to compile "htop" from source code, you will find it here.
If you are trying to find out the number of threads using cpu for a given pid I would use:
top -bc -H -n2 -p <pid> | awk '{if ($9 != "0.0" && $1 ~ /^[0-9]+$/) print $1 }' | sort -u | wc -l
If you want the number of threads per user in a linux system then you should use:
ps -eLf | grep <USER> | awk '{ num += $6 } END { print num }'
where as <USER> use the desired user name.
If you're interested in those threads which are really active -- as in doing something (not blocked, not timed_waiting, not reporting "thread running" but really waiting for a stream to give data) as opposed to sitting around idle but live -- then you might be interested in jstack-active.
This simple bash script runs jstack then filters out all the threads which by heuristics seem to be idling, showing you stack traces for those threads which are actually consuming CPU cycles.
First get the process ID (pid) by executing below command:
ps -ef | grep (for e.g ps -ef | grep java)
Now replace the pid in below command and execute to get the total thread count of a process.
ps huH p | wc -l
VisualVM can show clear states of threads of a given JVM process