I'm facing an issue.
We have a clean script using to clean old files, and sometimes we need stop it for and will start it again later. Like the below processes. We use kill -STOP $pid and kill -CONT $pid in check.sh to control the clean.sh, $pid is all the pids of clean.sh (at there, they are 23939, 25804):
root 4321 0.0 0.0 74876 1184 ? Ss 2015 0:25 crond
root 23547 0.0 0.0 102084 1604 ? S 2015 0:00 \_ crond
root 23571 0.0 0.0 8728 972 ? Ss 2015 0:00 \_ /bin/bash -c bash /home/test/sbin/check.sh >>/home/test/log/check.log 2>&1
root 23577 0.0 0.0 8732 1092 ? S 2015 0:00 \_ bash /home/test/sbin/check.sh
root 23939 0.0 0.0 8860 1192 ? S 2015 0:45 \_ bash /home/test/bin/clean.sh 30
root 25804 0.0 0.0 8860 620 ? S 2015 0:00 \_ bash /home/test/bin/clean.sh 30
root 25805 0.0 0.0 14432 284 ? T 2015 0:00 \_ ls -d ./455bb4cba6142427156d2b959b8b0986/120x60/ ./455bb4cba6142427156d2b959b8b0986/80x
root 25808 0.0 0.0 3816 432 ? S 2015 0:00 \_ wc -l
Once the check.sh stopped clean.sh, hours later, check.sh started clean.sh, but there is a strange thing, after a stop and continue, there is a child process 'ls -d ....', it's still stopping.
Could you tell me if it's caused by wrong use of the signal? And how can I modify it?
ok, same like my description is not clear, my bad English...
Not sure what's the reason, but there is a way to sovle it:
kill -CONT $pid
pkill -CONT -P $pid
This will continue the child process.
Related
On my Windows machine, I started a Docker container from docker compose. My entrypoint is a Go filewatcher that runs a task of a taskmanager on every filechange. The executed task builds and runs the Go program.
But before I can build and run the program again after filechanges I have to kill the previous running version. But every time I kill the app process, the container is also gone.
The goal is to kill only the svc1 process with PID 74 in this example. I tried pkill -9 svc1 and kill $(pgrep svc1). But every time the parent processes are killed too.
The commandline output from inside the container:
root#bf073c39e6a2:/app/cmd/svc1# ps -aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 2.5 0.0 104812 2940 ? Ssl 13:38 0:00 /go/bin/watcher
root 13 0.0 0.0 294316 7576 ? Sl 13:38 0:00 /go/bin/task de
root 74 0.0 0.0 219284 4908 ? Sl 13:38 0:00 /svc1
root 82 0.2 0.0 18184 3160 pts/0 Ss 13:38 0:00 /bin/bash
root 87 0.0 0.0 36632 2824 pts/0 R+ 13:38 0:00 ps -aux
root#bf073c39e6a2:/app/cmd/svc1# ps -afx
PID TTY STAT TIME COMMAND
82 pts/0 Ss 0:00 /bin/bash
88 pts/0 R+ 0:00 \_ ps -afx
1 ? Ssl 0:01 /go/bin/watcher -cmd /go/bin/task dev -startcmd
13 ? Sl 0:00 /go/bin/task dev
74 ? Sl 0:00 \_ /svc1
root#bf073c39e6a2:/app/cmd/svc1# pkill -9 svc1
root#bf073c39e6a2:/app/cmd/svc1
Switching to the containerlog:
task: Failed to run task "dev": exit status 255
2019/08/16 14:20:21 exit status 1
"dev" is the name of the task in the taskmanger.
The Dockerfile:
FROM golang:stretch
RUN go get -u -v github.com/radovskyb/watcher/... \
&& go get -u -v github.com/go-task/task/cmd/task
WORKDIR /app
COPY ./Taskfile.yml ./Taskfile.yml
ENTRYPOINT ["/go/bin/watcher", "-cmd", "/go/bin/task dev", "-startcmd"]
I expect only the process with the target PID is killed and not the parent process that spawned it it.
You can use process manager like "supervisord" and configure it to re-execute your script or the command even if you killed it's process which will keep your container up and running.
I'm running an rsync daemon (providing a mirror for the SaneSecurity signatures).
rsync is started like this (from runit):
/usr/bin/rsync -v --daemon --no-detach
And the config contains:
use chroot = no
munge symlinks = no
max connections = 200
timeout = 30
syslog facility = local5
transfer logging = no
log file = /var/log/rsync.log
reverse lookup = no
[sanesecurity]
comment = SaneSecurity ClamAV Mirror
path = /srv/mirror/sanesecurity
read only = yes
list = no
uid = nobody
gid = nogroup
But what I'm seeing is a lot of "lingering" rsync processes:
# ps auxwww|grep rsync
root 423 0.0 0.0 4244 1140 ? Ss Oct30 0:00 runsv rsync
root 2529 0.0 0.0 11156 2196 ? S 15:00 0:00 /usr/bin/rsync -v --daemon --no-detach
nobody 4788 0.0 0.0 20536 2860 ? S 15:10 0:00 /usr/bin/rsync -v --daemon --no-detach
nobody 5094 0.0 0.0 19604 2448 ? S 15:13 0:00 /usr/bin/rsync -v --daemon --no-detach
root 5304 0.0 0.0 11156 180 ? S 15:15 0:00 /usr/bin/rsync -v --daemon --no-detach
root 5435 0.0 0.0 11156 180 ? S 15:16 0:00 /usr/bin/rsync -v --daemon --no-detach
root 5797 0.0 0.0 11156 180 ? S 15:19 0:00 /usr/bin/rsync -v --daemon --no-detach
nobody 5913 0.0 0.0 20536 2860 ? S 15:20 0:00 /usr/bin/rsync -v --daemon --no-detach
nobody 6032 0.0 0.0 20536 2860 ? S 15:21 0:00 /usr/bin/rsync -v --daemon --no-detach
root 6207 0.0 0.0 11156 180 ? S 15:22 0:00 /usr/bin/rsync -v --daemon --no-detach
nobody 6292 0.0 0.0 20544 2744 ? S 15:23 0:00 /usr/bin/rsync -v --daemon --no-detach
root 6467 0.0 0.0 11156 180 ? S 15:25 0:00 /usr/bin/rsync -v --daemon --no-detach
root 6905 0.0 0.0 11156 180 ? S 15:29 0:00 /usr/bin/rsync -v --daemon --no-detach
(it's currently 15:30)
So there's processes (not even having dropped privileges!) hanging around since 15:10, 15:13 and the like.
And what are they doing?
Let's check:
# strace -p 5304
strace: Process 5304 attached
select(4, [3], NULL, [3], {25, 19185}^C
strace: Process 5304 detached
<detached ...>
# strace -p 5797
strace: Process 5797 attached
select(4, [3], NULL, [3], {48, 634487}^C
strace: Process 5797 detached
<detached ...>
This happended with both rsync from Ubuntu Xenial as well as installed from PPA (currently using rsync 3.1.2-1~ubuntu16.04.1york0 )
One process is created for each connection. Before a client selects the module the process does not know if it should drop privileges.
You can easily create such a process.
nc $host 873
You will notice that the connection will not be closed after 30s because the timeout is just a disk i/o timeout. The rsync client have a --contimeout option, but it seems that a server side option is missing.
In the end, I resorted to invoking rsync from (x)inetd instead of running it standalone.
service rsync
{
disable = no
socket_type = stream
wait = no
user = root
server = /usr/bin/timeout
server_args = -k 60s 60s /usr/bin/rsync --daemon
log_on_failure += USERID
flags = IPv6
}
As an additional twist, I wrapped the rsync invocation with timeout, adding another safeguard against long-running processes.
I made a PHP script which reads some data and starts a new process with pctnl_fork to do some work with the data. When the child processes are finished they stay in as process. ps aux shows me a list of processes like
demo 32229 0.0 0.0 0 0 pts/0 Z 12:23 0:00 [php] <defunct>
demo 32251 0.0 0.0 0 0 pts/0 Z 11:50 0:00 [php] <defunct>
demo 32284 0.0 0.0 0 0 pts/0 Z 11:50 0:00 [php] <defunct>
demo 32298 0.0 0.0 0 0 pts/0 Z 12:56 0:00 [php] <defunct>
demo 32303 0.0 0.0 0 0 pts/0 Z 11:50 0:00 [php] <defunct>
demo 32316 0.0 0.0 0 0 pts/0 Z 12:23 0:00 [php] <defunct>
Can I safely kill this processes as the parent process is still creating new processes to do some work? I know I should probably start the command piping to stderr (according to this topic Insane crond behavior. keeps making defunct bash processes now it is too late.
The parent process is running in the background.
After doing some research, it appears you'll have to kill the parent process for these defunct child processes to go away.
The most pertinent quote from the link says "You cannot kill a defunct process (a.k.a zombie) as it is already dead."
So as U said,
a command in your PHP, like
$a;
pcntl_waitpid($child_pid, $a, WNOHANG|WUNTRACED);
will do the job.
to me works, just fine !
I connect to a remote server using SSH
I was compiling using cmake and then make, it's not common to have a progress percentage in compilation process, but this time it has. I was watching the compilation process until my internet connection failed, so puTTY closed the session and I had to connect again to my server. I though that all the progress was lost, but i first make sure by watching the processes list by ps aux command, and I noticed that the processes related to the compilation are still running:
1160 tty1 Ss+ 0:00 /sbin/mingetty tty1
2265 ? Ss 0:00 sshd: root#pts/1
2269 pts/1 Ss 0:00 -bash
2353 pts/1 S+ 0:00 make
2356 pts/1 S+ 0:00 make -f CMakeFiles/Makefile2 all
2952 ? S 0:00 pickup -l -t fifo -u
3085 ? Ss 0:00 sshd: root#pts/0
3089 pts/0 Ss 0:00 -bash
3500 pts/1 S+ 0:01 make -f src/compiler/CMakeFiles/hphp_analysis.dir/bui
3509 pts/1 S+ 0:00 /bin/sh -c cd /root/hiphop/hiphop-php/src/compiler &&
3510 pts/1 S+ 0:00 /usr/bin/g++44 -DNO_JEMALLOC=1 -DNO_TCMALLOC=1 -D_GNU
3511 pts/1 R+ 0:03 /usr/libexec/gcc/x86_64-redhat-linux6E/4.4.4/cc1plus
3512 pts/0 R+ 0:00 ps ax
I would like to know if is possible to watch the current progress of the compilation by watching the previously closed terminal output. Something similar like 'cat /dev/vcsa1' or something
As per the comment above, you should have used screen.
As it is, you could try to peek at the file descriptors used by sshd and the shell that you started, but I don't think this will get you very far.
We have a convention whereby developers get into a server with their own username, and then sudo su - django where django is the user our apps run under.
I need to find out which developer is running a script as django. With ps faux :
root 26438 0.0 0.0 90152 3320 ? Ss 10:38 0:00 \_ sshd: fred [priv]
fred 26444 0.0 0.0 90152 1852 ? S 10:38 0:00 | \_ sshd: fred#pts/0
fred 26445 0.0 0.0 66052 1560 pts/0 Ss 10:38 0:00 | \_ -bash
root 27923 0.0 0.0 101052 1336 pts/0 S 10:46 0:00 | \_ su - django
django 27924 0.0 0.0 66188 1752 pts/0 S 10:46 0:00 | \_ - bash
django 31760 0.0 0.5 227028 42320 pts/0 S+ 11:10 0:01 | \_ python target_script.py
I can easily see what fred is up to. However I need to write a script to act on this info, and I can find no way to pull out "fred" and "target_script.py" in one line with ps ... euser,ruser,suser,fuser all say "django." Will I need to fumble through this ps faux output to get the info I need?
I found this old post when trying to find the same basic information. The easiest way I found was to use the "loginuid" file under /proc/[pid]. For example:
cat /proc/${processid}/loginuid
Sorry for resurrecting such and old post, but maybe someone will find it useful.
You used su - django. The " - " will make the new shell a login shell (see manpage of su), which let the child process forget its parent uids. That's why euser,ruser,suser,fuser all say "django".
So yes, you may have to fumble through the parent process id, or through "ps faux".