Plesk and CPU usage

[kharrazi]

Well, something strange happens to my CPU usage. My server is still not running any websites but my CPU usage is always around 35% (Dual Xeon/Windows2003).

The only process that is using the CPU resources (task manager) is "named.exe" (Plesk DNS server). Whenever I stop it from the Plesk Control Panel the CPU usage drops to 1% but if I start the DNS, usually after 10min the CPU usages goes up again to 35%.

My feeling is that there is something wrong. Anybody any idea?

Thanks,

 

[kharrazi]

Well, I installed the hotfix for the BIND problem but it still uses a lot of CPU.
It seems that this hotfix is not a solution and it gives me only the possibility to turn off the BIND services from the Plesk service manager.

My understanding is that if I turn the Name Services (BIND) off, my clients can not configure their DNS zones in thier reseller control panels anymore.

So what I have to do? I though Plesk will handle all of the DNS stuff smoothly.

 

[rcampbell]

I too am having this problem. I called Plesk and asked about this and they told me to send an email to pleskwin_at_sw-soft_dot_com. I am not even running any real websites yet and it is doing this.

What if I do not have to worry about resellers. Is there a fix for this?

 

[bmorejon]

I think I will give up of Plesk

 

[kharrazi]

Well I stopped continuing my business until I receive the hotfix. Because the pressure on my CPU will sooner or later harm it.

I also emailed the BIND developers (BIND is the open source DNS server which Plesk uses it) and they told me that this is not thier bug. So it has to be Plesk which is using BIND incorrectly or ....?

 

[jaytee]

Well, this seems to be a problem in BIND, not Plesk. We are investigating it nevertheless. It seems to only occur on SMP servers with Intel CPUs with Hyperthreading.

Try to disable HyperThreading and see if it helps.

 

[jaytee]

Originally posted by kharrazi
I also emailed the BIND developers (BIND is the open source DNS server which Plesk uses it) and they told me that this is not thier bug. So it has to be Plesk which is using BIND incorrectly or ....?

Or may be BIND developers which are not really willing to take a closer look into the problem?

What I see is that BIND server with no zones configured (i.e. no config at all and very little chance for Plesk developers to screw something up) is consuming 25% CPU on 2-way HT box after some time. Yes, it is definitely possible that it might be Plesk related, but I've seen it on the box where no Plesk was ever installed.

 

[rcampbell]

How do you fix the zones then? Is there a howto for this? Can I manually change this?

 

[jaytee]

Probably I did not express myself clearly. I was not talking about the fix, what I'm saying is that unconfigured BIND uses some CPU on some boxes (this effect is not 100% stable). If BIND is unconfigured, that leaves very little space for Plesk itself to be responsible for this.

We are working on the solution and I will publish the fix as soon as it will be available.

 

[bmorejon]

I stopped my business too.

SW-Soft give us a help !

 

[jaytee]

I respect your decision to stop your business, but it looks that BIND is only taking unused CPU cycles, and will give up some of that CPU time as soon as there are other tasks requiring it. Yes, it causes some overhead, but I don't see that impact as business critical.

If your experience is different, please let us know.

 

[rcampbell]

Thanks for clearing that up. Please let us know when you have discovered a fix for this.

 

[kharrazi]

I really appreciate the help and support of sw-soft people in trying to resolve the BIND/CPU issue.

I hope that the BIND guys also collaborate with you in finding the real source of the existing bug.

We all are looking forward for your solution or next hotfix.

 

[kharrazi]

Is it possible to assign the 'name.exe' only to one processor. I can't assign the affinity of 'name.exe' in task manager to one CPU. It gives me always 'access denied'.

As far as I know it is not possible to define the affinity of a 'service' , does anybody have any solution?

 

[Pablo]

Temp - Fix

After monitoring the "named.exe" (BIND 9) process I watch that the CPU load is generated exactly each hour after this service start.

So... when the load start, I reload the DNS Server and the load stop.

This is a TEMP FIX that works for me:

Just add a new Scheduled Task for every half hour to reload the DNS Service using the RNDC tool (Remote Name Daemon Controller for BIND):

PLESK_PATH\dns\bin\rndc.exe reload

This command makes BIND get reloaded and it stop consuming CPU.

Replace PLESK_PATH with your Plesk Installation Path.

 

[bmorejon]

I will wait for a hotfix from SW-Soft

 

[kharrazi]

Yes, creating a cron job (schedule) to reactivate the DNS can reduce the server load as like restarting it. Because whenever DNS server gets an unauthorized nslookup it would make it to reduce the CPU load.

I created a schedule to call the following VB script every 10min and it works fine:

Dim shell, fs
Set shell = WScript.CreateObject("WScript.Shell")
Set fs = CreateObject("Scripting.FileSystemObject")

Do
WScript.Sleep 600000
shell.Run "nslookup www.yourdomain.com"
shell.Run "nslookup www.mydomain.com"
shell.Run "nslookup www.everydomain.com"
Loop

Cheers,

 

[Salvatore]

When will a permanent fix be released from plesk regarding this issue?

Thank you very much

 

[PaulC]

This issue is fixed under Plesk 7.0.2

From the change log:

Workaround for "BIND high CPU utilization" issue added.

 

[Salvatore]

I have plesk 7.0.2 for windows server 2003 and the issue is not resolved, please advise, Thank you