Killing all the process of a command except first process
Solution 1
Below Example of apache2 process, it will kill all PID's except first one
pgrep apache2 |awk 'NR >= 2' | xargs -n1 echo kill
if output of above command looks fine , then you can remove echo
Solution 2
you can try this out:
ps -e --sort=start -o start,pid,cmd|grep <cmd>|egrep -v grep |sed 1d
this will give you the following formatted output:
start time, PID, command being executed
for i in `ps -e --sort=start -o start,pid,cmd|grep <cmd>|egrep -v grep |sed 1d`
do
kill -9 $i
done
replace the kill by echo first to ensure that it will kill the news ones.
Solution 3
You can do this for example with:
OLDEST_PID=$(pgrep -o 'DELETE OPERATION_CONTEXT')
test $OLDEST_PID && pgrep 'DELETE OPERATION_CONTEXT' | grep -vw $OLDEST_PID | xargs -r kill
The first line finds the oldest PID.
The second line checks first if $OLDEST_PID
contains something.
If yes, it list all matching processes, filters the $OLDEST_PID
out
and kill them (if any remain).
A better way is to avoid duplicated processes by adding lockfiles to the cron script like in this question.
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Ankit Vashistha
Updated on September 18, 2022Comments
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Ankit Vashistha over 1 year
I am sometimes stuck in a situation where a script/command kept in Cron runs more than once because of some reasons (the first instance is not completed fully, the second instance of the same process starts) and at some point of time these processes increase a lot and show system hanging etc. So, what I want as a temporary solution here is to check if there are more than one instances of the script/command say,
ps -ef | pgrep -f 'DELETE OPERATION_CONTEXT'
or directly kill all the processes of this command
ps -ef | pkill -f 'DELETE OPERATION_CONTEXT'
But I want an idea how I can kill all the processes of pgrepped command except for the first process (this would let one of the process to keep working and all other duplicates to get killed).
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Admin over 11 yearsif you post , output of pgrep then it would be easy using
xargs
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Admin over 11 yearsPreventing the duplicates might be a better idea? Check if file exist with a valid PID at startup (possibly event check its name vs $0). If it is invalid or doesn't exist, create a file with the PID and run the script. Delete file when script is complete. (Finding that a file is missing is much quicker than reading its contents, checking if it is a valid PID, etc...)
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Admin over 11 yearsYou do not need
ps -ef |
in front of pgrep/pkill. -
Admin over 11 yearsAs Gert wrote, it would be easier and more useful to ensure that only one instance of the cron job is running. See Quick-and-dirty way to ensure only one instance of a shell script is running at a time
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