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Setting up a load cap for a container: is this possible? [message #52056]

Wed, 20 May 2015 09:24

fabioganga
Messages: 3
Registered: May 2015
Location: Tenerife

Junior Member

Dear friends,

I am running a server with SolusVM (1 master + 3 slaves).

Quite often I have problems with individual containers having sudden peaks of high load (in one case, one container even reached over 2,000 which is totally unacceptable!).

I'm looking for a way (if at all possible) to set up a load cap for containers, so as not o have problems of any of them affecting the global performance of the node.

I don't want the container suspended if the cap is exceeded, it should just be a cap that cannot be exceeded.

Is this at all possible? I know it's not possible from within SolusVM, is there any workaround?

I need to resolve this problem, what is your best suggestion?

Thanks!

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Re: Setting up a load cap for a container: is this possible? [message #52057 is a reply to message #52056]

Wed, 20 May 2015 17:09

Paparaciz
Messages: 302
Registered: August 2009

Senior Member

write some script which monitors containers and if needed set some low limits for particular container.

if it is the same container everytime, just set lower limits so that it will not affect other containers in case of problem.

check cpuunits limit. I don't know is it working or no, but maybe it can help

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Re: Setting up a load cap for a container: is this possible? [message #52069 is a reply to message #52056]

Fri, 29 May 2015 14:04

speedbus
Messages: 4
Registered: May 2015

Junior Member

Checkout: It stops the VPS once it crosses the maxload (which is 10 in this case), you can change the vzctl stop command to vzctl restart as well

#! /bin/bash
export PATH="/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"
maxload="10"; # put here the max loadavg permitted
cat /dev/null > loads.txt;
vzlist -o ctid,laverage > loads.txt;
cat loads.txt | while read line; do
vm=$(echo ${line:0:5});
load=$(echo ${line} | cut -d'/' -f3);
load2=$(echo ${load} | cut -d'.' -f1);
if [ $load2 -gt $maxload ]
    then
    echo "stopping $vm - $load";
    vzctl stop $vm;
    echo "$vm - $load" | mail -s "$vm stopped for overload" your@email.com
fi
done

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Re: Setting up a load cap for a container: is this possible? [message #52070 is a reply to message #52069]

Fri, 29 May 2015 16:39

fabioganga
Messages: 3
Registered: May 2015
Location: Tenerife

Junior Member

speedbus wrote on Fri, 29 May 2015 14:04

Checkout: It stops the VPS once it crosses the maxload (which is 10 in this case), you can change the vzctl stop command to vzctl restart as well

#! /bin/bash
export PATH="/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"
maxload="10"; # put here the max loadavg permitted
cat /dev/null > loads.txt;
vzlist -o ctid,laverage > loads.txt;
cat loads.txt | while read line; do
vm=$(echo ${line:0:5});
load=$(echo ${line} | cut -d'/' -f3);
load2=$(echo ${load} | cut -d'.' -f1);
if [ $load2 -gt $maxload ]
    then
    echo "stopping $vm - $load";
    vzctl stop $vm;
    echo "$vm - $load" | mail -s "$vm stopped for overload" your@email.com
fi
done

Thanks ever so much, you're a star!!!

Will this script apply globally to the entire node?

How often would you recommend it is run by cron job?

Thanks!

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Re: Setting up a load cap for a container: is this possible? [message #52071 is a reply to message #52070]

Fri, 29 May 2015 17:46

speedbus
Messages: 4
Registered: May 2015

Junior Member

fabioganga wrote on Fri, 29 May 2015 16:39

speedbus wrote on Fri, 29 May 2015 14:04
Checkout: It stops the VPS once it crosses the maxload (which is 10 in this case), you can change the vzctl stop command to vzctl restart as well
#! /bin/bash
export PATH="/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"
maxload="10"; # put here the max loadavg permitted
cat /dev/null > loads.txt;
vzlist -o ctid,laverage > loads.txt;
cat loads.txt | while read line; do
vm=$(echo ${line:0:5});
load=$(echo ${line} | cut -d'/' -f3);
load2=$(echo ${load} | cut -d'.' -f1);
if [ $load2 -gt $maxload ]
    then
    echo "stopping $vm - $load";
    vzctl stop $vm;
    echo "$vm - $load" | mail -s "$vm stopped for overload" your@email.com
fi
done
Thanks ever so much, you're a star!!!

Will this script apply globally to the entire node?

How often would you recommend it is run by cron job?

Thanks!

>>Thanks ever so much, you're a star!!!
You're welcome Smile

>> Will this script apply globally to the entire node?
Yup, it'll apply to the whole node, each and every VPS on the node.

>> How often would you recommend it is run by cron job?
Run it every 5 minutes

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Re: Setting up a load cap for a container: is this possible? [message #52074 is a reply to message #52069]

Sun, 31 May 2015 16:37

fabioganga
Messages: 3
Registered: May 2015
Location: Tenerife

Junior Member

Thanks again speedbus.

I have tried launching the script manually to test it, and I get this error:

[root@servervps7 scripts]# sh antiload.sh
antiload.sh: line 10: [: too many arguments

line 10 is as follows in your script:

if [ $load2 -gt $maxload ]

What could the problem be? I love the idea of using your script!

Thanks!

Fabio

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