Automatically kill a process if it exceeds a given amount of RAM

Question

I work on large-scale datasets. When testing new software, a script will sometimes sneak up on me, quickly grab all available RAM, and render my desktop unusable. I'd like a way to set a RAM limit for a process so that if it exceeds that amount, it will be killed automatically. A language-specific solution probably won't work, as I use all sorts of different tools (R, Perl, Python, Bash, etc).

So is there some sort of process-monitor that will let me set a threshold amount of RAM and automatically kill a process if it uses more?

Solution 1

I would strongly advise not to do it. As suggested by @chrisamiller , setting ulimit will limit the RAM available with process.

But still if you are insisting then follow this procedure.

1. Save the following script as killif.sh:

   #!/bin/sh
   
   if [ $# -ne 2 ];
   then
       echo "Invalid number of arguments"
       exit 0
   fi
   
   while true;
   do
       SIZE=$(pmap $1|grep total|grep -o "[0-9]*")
       SIZE=${SIZE%%K*}
       SIZEMB=$((SIZE/1024))
       echo "Process id =$1 Size = $SIZEMB MB"
       if [ $SIZEMB -gt $2 ]; then
           printf "SIZE has exceeded.\nKilling the process......"
           kill -9 "$1"
           echo "Killed the process"
           exit 0
       else
           echo "SIZE has not yet exceeding"
       fi
   
       sleep 10
   done
   

2. Now make it executable.

   chmod +x killif.sh
   

3. Now run this script on terminal. Replace PROCID with actual process id and SIZE with size in MB.

   ./killif.sh PROCID SIZE
   

   For example:

   ./killif.sh 132451 100
   

   If SIZE is 100 then process will be killed if its RAM usage goes up beyond 100 MB.

Caution: You know what are you trying to do. Killing process is not a good idea. If that process has any shutdown or stop command then edit the script and replace kill -9 command with that shutdown command.

Solution 2

I hate to be the guy who answers his own question, but this morning I found an alternative method, wrapped into a nice little utility. It'll limit CPU time or memory consumption:

https://github.com/pshved/timeout

I'm giving this one a shot first but upvotes to Amey Jah for the nice answer. I'll check it out if this one fails me.

Solution 3

This was too big to fit a comment. I modified Amey's original script to include a pgrep, so instead of having to manually enter the process id, you can just exclude by name. For example, ./killIf.sh chrome 4000 kills any chrome process that exceeds 4GB in memory usage.

#!/bin/sh

# $1 is process name
# $2 is memory limit in MB

if [ $# -ne 2 ];
then
    echo "Invalid number of arguments"
    exit 0
fi

while true;
do
    pgrep "$1" | while read -r procId;
    do
        SIZE=$(pmap $procId | grep total | grep -o "[0-9]*")
        SIZE=${SIZE%%K*}
        SIZEMB=$((SIZE/1024))
        echo "Process id = $procId Size = $SIZEMB MB"
        if [ $SIZEMB -gt $2 ]; then
            printf "SIZE has exceeded.\nKilling the process......"
            kill -9 "$procId"
            echo "Killed the process"
            exit 0
        else
            echo "SIZE has not yet exceeding"
        fi
    done

    sleep 1
done

Be careful to select a narrow grep string and a big enough memory limit to not unnecessarily kill unintended processes.

Solution 4

Try the prlimit tool, from the util-linux package. It runs a program with resource limits. It uses the prlimit system call to set up the limits, which are then enforced purely by the kernel.

You can configure 16 limits, including:

• maximum amount of CPU time in seconds
• maximum number of user processes
• maximum resident set size ("used memory")
• maximum size a process may lock into memory
• size of virtual memory
• maximum number of open files
• maximum number of file locks
• maximum number of pending signals
• maximum bytes in POSIX message queues

View more solutions

Comments

[Uri Herrera]

askubuntu.com/questions/54202/…

[Chriskin]

@ Uri : At that thread i only got a partial (only for the cpu part of my question) - and not optimal - answer. He asks about RAM usage.

[chrisamiller]

Hrmm - this superuser thread seems to have a reasonable suggestion using ulimit: superuser.com/questions/66383/restrict-ram-for-user-or-proce‌​ss

[Denwerko]

i would consider putting little sleep there, for example sleep 0.5...

[jaseelder]

@George Edison How did you do that. When I tried to paste, it was giving me weirdly formatted text. Denwerko: Where would you like to put the sleep. I have already put a sleep of 10 seconds in the while loop

[chrisamiller]

Thanks for the solution, as noted below, I may check it out. Why all the dire warnings about killing processes, though? Cluster management software (LSF, PBS, et al) does this all the time when a process exceeds the amount of resources that it requested, with no dire consequences. I agree that this is not a good solution for new users who are likely to misapply it, but in the right circumstances, this can be quite useful.

[jaseelder]

@chrisamiller I have put up a warning for future readers. In your case, you know the implications but future reader of this post might not be aware of such implications.

[Sanam Patel]

+1 Answering your own question is OK!

[jterm]

Can you elaborate on why not to do it?

[Mirror Mirage]

works like a charm. helps to keep the eternally memory leaking telegram desktop app in check.