Resolved Enabling CPU Limit in Subscription Plans with PLESK on CENTOS 7 Server with Cgroups

[AnibalB]

Server operating system version

CentOS Linux 7.9.2009 (Core)

Plesk version and microupdate number

18.0.58

Hello, I have a dedicated CENTOS 7 server with a PLESK license which includes a Resource Controller (cgroups). However, I can only control the limits of RAM and Disk, I cannot limit CPU in subscription plans, as it appears in the documentation, I need to know how I can enable the CPU limit option.

Regards

 

[AnibalB]

 

[AnibalB]

Furthermore, if I use PLESK CLI through the command terminal, the following appears to me:

plesk bin service_plan -u "Básico" -cgroups_cpu_usage 50
Unrecognized option: 'cgroups_cpu_usage'


exit status 1

 

[Peter Debik]

Could you please show the output of
plesk db "select value from ServiceNodeEnvironment where section = 'resourceController' and name = 'features'"
and
plesk db "select * from ServiceNodeConfiguration where section = 'resourceController' and name = 'enabled'"
?

 

[AnibalB]

Could you please show the output of
plesk db "select value from ServiceNodeEnvironment where section = 'resourceController' and name = 'features'"
and
plesk db "select * from ServiceNodeConfiguration where section = 'resourceController' and name = 'enabled'"
?

plesk db "select value from ServiceNodeEnvironment where section = 'resourceController' and name = 'features'"
| value                                                                                 |
+---------------------------------------------------------------------------------------+
| {"cpu": false, "cpuacct": true, "memory": true, "blkio": true, "vhosts_blkio": true} |
+---------------------------------------------------------------------------------------+

plesk db "select * from ServiceNodeConfiguration where section = 'resourceController' and name = 'enabled'"

+---------------+--------------------+---------+-------+
| serviceNodeId | section            | name    | value |
+---------------+--------------------+---------+-------+
|             1 | resourceController | enabled | 1     |
+---------------+--------------------+---------+-------+

 

[Peter Debik]

The entries are correct, but you can see that "cpu" is set to "false". It should be "true" to enable cpu accounting. I could not find out why this could be set to "false". Personally I think it should be safe to set it to "true" and see what happens. However, if the server is in production already, it might be better to open a support ticket on the question whether the setting can be changed without risk, because support can ask engineers on the details. In a default installation the setting is "true". Maybe you got your Plesk image from your provider and he set it to "false"?

 

[AnibalB]

The entries are correct, but you can see that "cpu" is set to "false". It should be "true" to enable cpu accounting. I could not find out why this could be set to "false". Personally I think it should be safe to set it to "true" and see what happens. However, if the server is in production already, it might be better to open a support ticket on the question whether the setting can be changed without risk, because support can ask engineers on the details. In a default installation the setting is "true". Maybe you got your Plesk image from your provider and he set it to "false"?

I manually changed that variable to ‘true,’ and now the CPU limitation settings are visible. However, if I uninstall the cgroup component using Plesk’s autoinstaller and then reinstall it, the CPU limitation settings become hidden and deactivated again. I use the official Plesk update server as the source for updates.

Any idea what might be causing this?

 

[Peter Debik]

Any idea what might be causing this?

A team member more knowledgeable in this matter than me suggests that it could be the kernel that does not support cgroups. Plesk detects that, hence disables the option. What's the output of "uname -r" on your system?

 

[AnibalB]

When I try to modify the CPU limits for a subscription manually, I encounter this message

 

[AnibalB]

A team member more knowledgeable in this matter than me suggests that it could be the kernel that does not support cgroups. Plesk detects that, hence disables the option. What's the output of "uname -r" on your system?

4.19-ovh-xxxx-std-ipv6-64

 

[AnibalB]

Would changing the kernel to the official one solve this issue?

Do you advise me to follow this tutorial? OVH Install CentOS7 official kernel on dedicated server with soft raid configured.

 

[Peter Debik]

So obviously the server has an individually configured kernel. Unfortunately, only OVH will be able to tell you what their kernel does different, but I assume that indeed the cpu cgroups functionality is absent.

 

[AnibalB]

At the end, I have performed the kernel change and now it works correctly.