Forwarded to devs CGrpus change CPU Limit over 999 it does not work

[B4c4rd1]

TITLE:

CGroups change CPU Limit over 999 it does not work​

PRODUCT, VERSION, OPERATING SYSTEM, ARCHITECTURE:

Plesk Onyx, Version 17.5.3 Update #21, Ubuntu 16.04.2 LTS‬, x64​

PROBLEM DESCRIPTION:

It is not possible to set CGroups cpu limit higher than 999.

You can only enter 3 digits.​

STEPS TO REPRODUCE:

Try to enter more than 3 digits​

ACTUAL RESULT:

Only 3 digits can be entered​

EXPECTED RESULT:

A minimum of 4 digits should be entered for example 1200​

ANY ADDITIONAL INFORMATION:

​

YOUR EXPECTATIONS FROM PLESK SERVICE TEAM:

Confirm bug​

 

[Fred Perez]

Did you try to contact the support of plesk?

 

[B4c4rd1]

Why? This is a bug or a feature ticket

 

[IgorG]

EXPECTED RESULT:
A minimum of 4 digits should be entered for example 1200

Cgroups Manager (Linux)

If the server has multiple CPU cores, the available CPU amount is equal to 100% * the number of CPU cores. For example, if your server has 4 CPU cores, the available CPU amount is 400%.

Sorry, but could you please confirm that your server really has 12 CPU cores?
Are you sure that "A minimum of 4 digits should be entered" is really necessary? This means that you need to have >=10 CPU cores.

 

[B4c4rd1]

Yes! 12 cores (2 sockets) 24 threads with intel. Next server comes with 2 sockets and 2 threadripper.

 

[IgorG]

You could set it to unlimited for your rare case.

 

[B4c4rd1]

Why rare?

Here is apparently a communication error. CGroups works with CPU-threads. 100% power = theoretically 1 thread, distributed to all existing threads. (Plesk CGroups)

You can test it yourself.

Examples that are not rare now:

Intel® Xeon® E5-1650 v3 Hexa-Core Haswell, with 12 threads (6 cores) the possibility to enter 1200%.

AMD Ryzen 7 1700X Octa-Core "Summit Ridge" (Zen), with 16 threads (8 cores) the possibility to enter 1600%.

With a Ryzen CPU is now about € 70,21 monthly.

All with a single socket.

This is the future, or is it already the future? Is Plesk a future product?

 

[B4c4rd1]

Set CGroups CPU limit = 100% (distributed on 4 threads with 2 cores)

test with AB

Result:

 

[IgorG]

Ok. Thank you! Bugreport PPPM-7097 has been submitted.

 

[custer]

Why rare?

[...]

Examples that are not rare now:

Intel® Xeon® E5-1650 v3 Hexa-Core Haswell, with 12 threads (6 cores) the possibility to enter 1200%.

AMD Ryzen 7 1700X Octa-Core "Summit Ridge" (Zen), with 16 threads (8 cores) the possibility to enter 1600%.

Hi,

The question is actually not about the existence of CPUs that support 12+ threads (we know they exist), the question is about your business case: what are you trying to accomplish by entering 1200% as a CPU limit for a subscription? This basically amounts to setting the CPU limit to Unlimited -- and Unlimited checkbox is already available. Can you tell us more about your scenario?

 

[B4c4rd1]

Hi,

What do we use the plugin for?

1. Quite simply, I use the plugin in principle for it that no 100% cpu-utilization comes when a customer takes a DDoS attack.

2. You can always have incorrect Wordpress plugins installed. If this plugin would take full advantage of the CPU, all customers on the server would be affected. Therefore, for us unlimited is not an option.

3. In addition, we offer packages where the customer can adjust the CPU limit himself. Of course for a certain extra charge.

We have a capacity of 3200%, why can I then give a customer only 999%? That does not yet illuminate me. The 1200% were just one example. The plugin-limit is 999%.

Many thanks for your help!

 

[B4c4rd1]

@custer

Will this now be implemented?

 

[custer]

@custer

Will this now be implemented?

Yep. As a matter of fact, we've already fixed this for Plesk Onyx 17.0 (in MU #39), and we're planning to release the bugfix for 17.5 soon. Stay tuned!

 

[custer]

Heads up everyone: the fix was released in Plesk 17.5 MU #28 and Plesk 17.0 MU#39 earlier today. View the full changelog here: Change Log for Plesk

@B4c4rd1 -- here you go! Let us know if you encounter any issues with the fix.

 

[B4c4rd1]

@custer

we found another bug with this adjustment.

We get the following error message when restoring backups:

Execution of /opt/psa/admin/plib/api-cli/domain_pref.php --update XXX -cgroups_cpu_usage 150 -ignore-nonexistent-options failed with return code 1. Stderr is Cannot update domain: Wrong syntax for command's '-cgroups_cpu_usage' parameter. '150' does not match the pattern '/^(-1|(?:100|[1-9][0-9]?)[%]?)$/i'.