Given this C program:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
int main(void) {
pid_t pid;
if ((pid = fork()) >= 0) {
if (pid == 0) {
exit(0);
} else {
sleep(999);
}
}
return 0;
}
after running:
$ gcc -o zombie zombie.c
$ ./zombie &
$ ps -f
only the parent process is showing:
501 77474 74651 0 2:36PM ttys000 0:00.00 ./zombie
On Linux the same program shows this:
osboxes 6900 6835 0 13:37 pts/1 00:00:00 ./zombie
osboxes 6903 6900 0 13:37 pts/1 00:00:00 [zombie] <defunct>
Now, strangely, on OSX when starting more than one zombie programs..
$ ./zombie &
$ ./zombie &
$ ps -f
.. the zombie processes (in brackets) show up:
501 77653 74651 0 2:39PM ttys000 0:00.00 ./zombie
501 77664 74651 0 2:39PM ttys000 0:00.00 ./zombie
501 77667 77664 0 2:39PM ttys000 0:00.00 (zombie)
What's the reason for this?
Related
I have a Gearman worker in a shell script started with perp in the following way:
runuid -s gds \
/usr/bin/gearman -h 127.0.0.1 -t 1000 -w -f gds-rel \
-- xargs /home/gds/gds-rel-worker.sh < /dev/null 2>/dev/null
The worker only does some input validation and calls another shell script run.sh that invokes bash, curl, Terragrunt, Terraform, Ansible and gcloud to provision and update resources in GCP like this:
./run.sh --release 1.2.3 2>&1 >> /var/log/gds-release
The script is intended to run unattended. The problem I have is that after the job finishes successfully (that's both shell scripts run.sh and gds-rel-worker.sh) the Gearman job remains executing, because the child process becomes zombie (see last line below).
root 144748 1 0 Apr29 ? 00:00:00 perpboot -d /etc/perp
root 144749 144748 0 Apr29 ? 00:00:00 \_ tinylog -k 8 -s 100000 -t -z /var/log/perp/perpd-root
root 144750 144748 0 Apr29 ? 00:00:00 \_ perpd /etc/perp
root 2492482 144750 0 May14 ? 00:00:00 \_ tinylog (gearmand) -k 10 -s 100000000 -t -z /var/log/perp/gearmand
gearmand 2492483 144750 0 May14 ? 00:00:08 \_ /usr/sbin/gearmand -L 127.0.0.1 -p 4730 --verbose INFO --log-file stderr --keepalive --keepalive-idle 120 --keepalive-interval 120 --keepalive-count 3 --round-robin --threads 36 --worker-wakeup 3 --job-retries 1
root 2531800 144750 0 May14 ? 00:00:00 \_ tinylog (gds-rel-worker) -k 10 -s 100000000 -t -z /var/log/perp/gds-rel-worker
gds 2531801 144750 0 May14 ? 00:00:00 \_ /usr/bin/gearman -h 127.0.0.1 -t 1000 -w -f gds-rel -- xargs /home/gds/gds-rel-worker.sh
gds 2531880 2531801 0 May14 ? 00:00:00 \_ [xargs] <defunct>
So far I have traced the problem to run.sh, because if I replace its call with something simpler (e.g. echo "Hello"; sleep 5) the worker does not hang. Unfortunately, I have no clue what is causing the problem. The script run.sh is rather long and complex, but has been working without a problem so far. Tracing the worker process I see this:
getpid() = 2531801
write(2, "gearman: ", 9) = 9
write(2, "gearman_worker_work", 19) = 19
write(2, " : ", 3) = 3
write(2, "gearman_wait(GEARMAN_TIMEOUT) ti"..., 151) = 151
write(2, "\n", 1) = 1
sendto(5, "\0REQ\0\0\0'\0\0\0\0", 12, MSG_NOSIGNAL, NULL, 0) = 12
recvfrom(5, "\0RES\0\0\0\n\0\0\0\0", 8192, MSG_NOSIGNAL, NULL, NULL) = 12
sendto(5, "\0REQ\0\0\0\4\0\0\0\0", 12, MSG_NOSIGNAL, NULL, 0) = 12
poll([{fd=5, events=POLLIN}, {fd=3, events=POLLIN}], 2, 1000) = 1 ([{fd=5, revents=POLLIN}])
sendto(5, "\0REQ\0\0\0'\0\0\0\0", 12, MSG_NOSIGNAL, NULL, 0) = 12
recvfrom(5, "\0RES\0\0\0\6\0\0\0\0\0RES\0\0\0(\0\0\0QH:terra-"..., 8192, MSG_NOSIGNAL, NULL, NULL) = 105
pipe([6, 7]) = 0
pipe([8, 9]) = 0
clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x7fea38480a50) = 2531880
close(6) = 0
close(9) = 0
write(7, "1.2.3\n", 18) = 6
close(7) = 0
read(8, "which: no terraform-0.14 in (/us"..., 1024) = 80
read(8, "Identity added: /home/gds/.ssh/i"..., 1024) = 54
read(8, 0x7fff6251f5b0, 1024) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=2531880, si_uid=1006, si_status=0, si_utime=0, si_stime=0} ---
read(8,
So the worker continues reading standard output even though the child has finished successfully and presumably closed it. Any ideas how to catch what causes this problem?
I was able to solve it. The script run.sh was starting ssh-agent, which opens a socket and since Gearman redirects all outputs the worker continued reading the open file descriptor even after the script successfully completed.
I found it by examining the open file descriptors for the Gearman worker process after it hang:
# ls -l /proc/2531801/fd/*
lr-x------. 1 gds devops 64 May 17 11:26 /proc/2531801/fd/0 -> /dev/null
l-wx------. 1 gds devops 64 May 17 11:26 /proc/2531801/fd/1 -> 'pipe:[9356665]'
l-wx------. 1 gds devops 64 May 17 11:26 /proc/2531801/fd/2 -> 'pipe:[9356665]'
lr-x------. 1 gds devops 64 May 17 11:26 /proc/2531801/fd/3 -> 'pipe:[9357481]'
l-wx------. 1 gds devops 64 May 17 11:26 /proc/2531801/fd/4 -> 'pipe:[9357481]'
lrwx------. 1 gds devops 64 May 17 11:26 /proc/2531801/fd/5 -> 'socket:[9357482]'
lr-x------. 1 gds devops 64 May 17 11:26 /proc/2531801/fd/8 -> 'pipe:[9369888]'
Then identified the processes using file node for the pipe in file descriptor 8 that German worker continued reading:
# lsof | grep 9369888
gearman 2531801 gds 8r FIFO 0,13 0t0 9369888 pipe
ssh-agent 2531899 gds 9w FIFO 0,13 0t0 9369888 pipe
And finally listed files opened by ssh-agent and found what stands behind file descriptor 3:
# ls -l /proc/2531899/fd/*
lrwx------. 1 root root 64 May 17 11:14 /proc/2531899/fd/0 -> /dev/null
lrwx------. 1 root root 64 May 17 11:14 /proc/2531899/fd/1 -> /dev/null
lrwx------. 1 root root 64 May 17 11:14 /proc/2531899/fd/2 -> /dev/null
lrwx------. 1 root root 64 May 17 11:14 /proc/2531899/fd/3 -> 'socket:[9346577]'
# lsof | grep 9346577
ssh-agent 2531899 gds 3u unix 0xffff89016fd34000 0t0 9346577 /tmp/ssh-0b14coFWhy40/agent.2531898 type=STREAM
As a solution I added kill of the ssh-agent before exit from run.sh script and now there are no jobs hanging due to zombie process.
Here is the 'smem' command I run on the Redhat/CentOS Linux system. I expect the output be printed without the fields with zero size however I would expect the heading columns.
smem -kt -c "pid user command swap"
PID User Command Swap
7894 root /sbin/agetty --noclear tty1 0
9666 root ./nimbus /opt/nimsoft 0
7850 root /sbin/auditd 236.0K
7885 root /usr/sbin/irqbalance --fore 0
11205 root nimbus(hdb) 0
10701 root nimbus(spooler) 0
8446 trapsanalyzer1 /opt/traps/analyzerd/analyz 0
50316 apache /usr/sbin/httpd -DFOREGROUN 0
50310 apache /usr/sbin/httpd -DFOREGROUN 0
3971 root /usr/sbin/lvmetad -f 36.0K
63988 root su - 0
7905 ntp /usr/sbin/ntpd -u ntp:ntp - 4.0K
7876 dbus /usr/bin/dbus-daemon --syst 44.0K
9672 root nimbus(controller) 0
7888 root /usr/lib/systemd/systemd-lo 0
63990 root -bash 0
59978 postfix pickup -l -t unix -u 0
3977 root /usr/lib/systemd/systemd-ud 736.0K
9016 postfix qmgr -l -t unix -u 0
50303 root /usr/sbin/httpd -DFOREGROUN 0
3941 root /usr/lib/systemd/systemd-jo 52.0K
8199 root //usr/lib/vmware-caf/pme/bi 0
8598 daemon /opt/quest/sbin/.vasd -p /v 0
8131 root /usr/sbin/vmtoolsd 0
7881 root /usr/sbin/NetworkManager -- 8.0K
8364 root /opt/puppetlabs/puppet/bin/ 0
8616 daemon /opt/quest/sbin/.vasd -p /v 0
23290 root /usr/sbin/rsyslogd -n 3.8M
64091 root python /bin/smem -kt -c pid 0
7887 polkitd /usr/lib/polkit-1/polkitd - 0
8363 root /usr/bin/python2 -Es /usr/s 0
53606 root /usr/share/metricbeat/bin/m 0
24631 nagios /usr/local/ncpa/ncpa_passiv 0
24582 nagios /usr/local/ncpa/ncpa_listen 0
7886 root /opt/traps/bin/authorized 76.0K
7872 root /opt/traps/bin/pmd 12.0K
8374 root /opt/puppetlabs/puppet/bin/ 0
7883 root /opt/traps/bin/trapsd 64.0K
----------------------------------------------------
54 10 5.1M
Like this?:
$ awk '$NF!=0' file
PID User Command Swap
7850 root /sbin/auditd 236.0K
...
7883 root /opt/traps/bin/trapsd 64.0K
----------------------------------------------------
54 10 5.1M
But instead of using the form awk ... file you'd probably like to smem ... | awk '$NF!=0'.
Could you please try following, for extra precautions removing the space from last fields(in case it is there).
smem -kt -c "pid user command swap" | awk 'FNR==1{print;next} {sub(/[[:space:]]+$/,"")} $NF==0{next} 1'
I need to kill a windows procces that were started by the programm called from cygwin.
Here's what I do:
${wccoaDirNix}/bin/WCCILpmon.exe -proj ${projName} -user root: &
This process creates other windows process:
$ ps -W
PID PPID PGID WINPID TTY UID STIME COMMAND
1960 1 1960 1960 ? 197609 19:21:57 /usr/bin/mintty
7316 0 0 7316 ? 0 19:21:57 C:\Windows\System32\conhost.exe
1700 1960 1700 1576 pty1 197609 19:21:57 /usr/bin/bash
I 10760 9840 10760 7560 pty0 197609 19:25:47 /usr/bin/bash
32 10760 10760 32 pty0 197609 19:26:28 /cygdrive/c/Siemens/Automation/WinCC_OA/3.14/bin/WCCILpmon
6264 0 0 6264 ? 0 19:26:28 C:\Siemens\Automation\WinCC_OA\3.14\bin\WCCILpmon.exe
8420 0 0 8420 ? 0 19:26:29 C:\Siemens\Automation\WinCC_OA\3.14\bin\WCCILdata.exe
6336 0 0 6336 ? 0 19:26:29 C:\Windows\System32\conhost.exe
2808 0 0 2808 ? 0 19:26:30 C:\Siemens\Automation\WinCC_OA\3.14\bin\WCCILevent.exe
6784 0 0 6784 ? 0 19:26:30 C:\Windows\System32\conhost.exe
2972 0 0 2972 ? 0 19:26:30 C:\Siemens\Automation\WinCC_OA\3.14\bin\WCCOActrl.exe
11004 0 0 11004 ? 0 19:26:30 C:\Windows\System32\conhost.exe
9536 0 0 9536 ? 0 19:26:31 C:\Siemens\Automation\WinCC_OA\3.14\bin\WCCILsim.exe
7372 0 0 7372 ? 0 19:26:31 C:\Windows\System32\conhost.exe
9128 0 0 9128 ? 0 19:26:31 C:\Siemens\Automation\WinCC_OA\3.14\bin\WCCOAui.exe
3964 0 0 3964 ? 0 19:27:48 C:\Siemens\Automation\WinCC_OA\3.14\bin\WCCILdatabg.exe
How can i kill them?
I tried to kill them by the following command:
ps -W | grep "WCC" | awk '{print $1}' | xargs kill -f;
But it does not work as it should, it kills all processes in which name there are letters WCС, and I need to terminate only the child processes of WCCILpmon.exe
I also read the question on cygwinlist about same problem
And it upset me, is there no way to realize it?
As you need to kill a NOT cygwin process, it is better to use
windows specific program.
One example is:
https://learn.microsoft.com/en-us/sysinternals/downloads/pskill
I have the following timey.cpp code in RedHat 2.6.32 x86_64:
using namespace std ;
int main()
{
while( 1 ){
char x[64]={0} ;
strcpy( x,"1234567890") ;
std::string s = x ;
std::cout << "(" << x << ")" << std::endl ;
struct timeval localtimex ;
long secs,usecs ;
gettimeofday(&localtimex,0x00) ;
secs = localtimex.tv_sec ;
usecs = localtimex.tv_usec ;
//long mills = (time.tv_sec * 1000) + (time.tv_usec / 1000 ) ;
printf("secs=(%d),usecs=(%d)\n",secs,usecs) ;
sleep( 1 ) ;
} //while
}
in /home/informix/test, compiled by g++ --std=c++0x timey.cpp -o timey.exe,
and the shell timey.sh:
source /etc/bashrc
nohup /home/informix/test/timey.exe &
Then I run timey.sh by:
/home/informix/test/timey.sh
and take a look if timey.exe runs by:
ps -ef | grep timey
It seems timey.exe runs as expected:
informix 41340 1 0 10:32 pts/10 00:00:00 /home/informix/test/timey.exe
What confuses me is that I add this shell to crontab:
38 10 * * 1-5 informix /home/informix/test/timey.sh
and restart crond:
/etc/init.d/crond restart
What surprises me is I see 4 copies of timey.exe running:
ps -ef | grep timey
informix 41498 1 0 10:38 ? 00:00:00 /home/informix/test/timey.exe
informix 41499 1 0 10:38 ? 00:00:00 /home/informix/test/timey.exe
informix 41529 1 0 10:38 ? 00:00:00 /home/informix/test/timey.exe
informix 41561 1 0 10:38 ? 00:00:00 /home/informix/test/timey.exe
What did I do wrong so that 4 copies of timey.exe are running?
I see the following in /var/log/cron:
Jul 2 10:38:01 localhost CROND[41440]: (informix) CMD (/home/informix/test/timey.sh )
Jul 2 10:38:01 localhost CROND[41439]: (informix) CMD (/home/informix/test/timey.sh )
Jul 2 10:38:01 localhost CROND[41491]: (informix) CMD (/home/informix/test/timey.sh )
Jul 2 10:38:01 localhost CROND[41533]: (informix) CMD (/home/informix/test/timey.sh )
It seems that crond really ran timey.sh 4 times, but why?
Also:
In RedHat 2.6.32-279.el6.x86_64, it works!
In RedHat 2.6.32-358.el6.x86_64, it does not work!
I have an output from the 'multipath -ll' command
From RHEL:
mpath114 (3600507680283095ea8000000000004fa) dm-28 IBM,2145
[size=200G][features=1 queue_if_no_path][hwhandler=0][rw]
\_ round-robin 0 [prio=50][active]
\_ 19:0:0:40 sdea 128:32 [active][ready]
\_ 20:0:1:40 sdeb 128:48 [active][ready]
\_ 20:0:1:41 sdec 128:16 [failed][faulty]
\_ round-robin 0 [prio=10][enabled]
\_ 20:0:0:40 sdba 67:64 [active][ready]
\_ 19:0:1:40 sdgg 131:192 [active][ready]
mpath131 (3600507680283095ea800000000000504) dm-39 IBM,2145
[size=10G][features=1 queue_if_no_path][hwhandler=0][rw]
\_ round-robin 0 [prio=50][active]
\_ 20:0:1:1 sdbl 67:240 [active][ready]
\_ 19:0:0:1 sdc 8:32 [active][ready]
\_ round-robin 0 [prio=10][enabled]
\_ 19:0:1:1 sdet 129:80 [active][ready]
\_ 20:0:0:1 sdk 8:160 [active][ready]
[..]
Or from SLES server:
mpathmzp (36005076801c7061ef800000000000089) dm-0 IBM,2145
size=10G features='1 queue_if_no_path' hwhandler='0' wp=rw
|-+- policy='round-robin 0' prio=50 status=enabled
| `- 67:0:2:0 sde 8:64 active ready running
| `- 68:0:0:1 sdl 8:76 failed faulty running
`-+- policy='round-robin 0' prio=10 status=enabled
|- 67:0:3:0 sdc 8:32 active ready running
`- 68:0:0:0 sdd 8:48 active ready running
[..]
I would like to parse it (preferably with awk or bash), to display summary of the configuration.
It should print the pseudo multipath device and the number of active paths and the failed (if any)
Sample:
dm-39, 10G, Total: 4 paths, active: 4, failed: 0
dm-28, 200G, Total: 5 paths, active: 4, failed: 1
Same for the SLES:
dm-0, 10G, Total: 4 paths, active: 3, failed: 1
If also possible, I'd like to sort the output so that the paths with no failed and most active paths are on top, and end with the devicess with the failed paths.
Thanks for helping!
This awk should do:
multipath -ll | awk 'NR>1 {r=f=0;for (i=1;i<=NF;i++) if ($i~/ready/) r++; else if ($i~/faulty/) f++;split($5,a,"=|]");print $3,a[2]"\tTotal: "r+f" paths, active: "r,"failed: "f}' RS="mpath" OFS=", "
dm-28, 200G Total: 5 paths, active: 4, failed: 1
dm-39, 10G Total: 4 paths, active: 4, failed: 0