topic Re: how to use CPU Throttle ? in QlikView

how to use CPU Throttle ?

mohamed_ahid — Mon, 26 Jan 2026 18:19:17 GMT

Hi every body ,

on my server i have several warnings about over use of CPU (99%) .

i try to limite the % of cpu used on server to avoid these kind of message .In performance we have CPU Throttle and CPU Affinity .

what is the aim and the difference of using each other ?

how to use CPU Throttle ti limite the use of CPU to 90 % (0% means no throttling . 100% is throttling ?)

thx

Re: how to use CPU Throttle ?

mohamed_ahid — Tue, 10 Mar 2015 09:44:01 GMT

Someone ?!

Re: how to use CPU Throttle ?

Peter_Cammaert — Tue, 10 Mar 2015 10:08:07 GMT

The big question here is: what services are running on the machine with cpu starvation?

The two settings you mentioned apply to the QVS process only. CPU Affinity assigns cores to the QVS process. Every disabled checkbox means that this CPU core wil not be used by the QVS process. The CPU Throttling-setting is a bit wacky. Setting a percentage level will impose a best effort limit to what QVS will do with the remainder of the CPU cores . Except if you set the Throttling level to 0% meaning that the QVS process doesn't do any throttling at all.

Back to my opening: QDS & QVB do not obey any of these nice limitations. You can disable CPU cores for QVB reloads, But just like there is no restraint on the memory usage of a reload, a QVB process will use one or more cores to the max if it feels like it.

And then there still is Windows...

What applications/services is your server hosting?

Peter

Re: how to use CPU Throttle ?

mohamed_ahid — Tue, 10 Mar 2015 10:18:11 GMT

Thx.

my server is hosting only QV server .For RAM there is no probleme (16 go is enough) but with my 8 cores it's another story ,I get 99% used on it while loading .

so if i want to limit the use of cpu to 90% i have to use CPU affinity or CPU throttle?

Re: how to use CPU Throttle ?

Peter_Cammaert — Tue, 10 Mar 2015 10:43:31 GMT

Even if you use CPU Throttling (say at 90%), that setting will apply only to the QVS service. Every time a reload job starts, your server will again experience cpu starvation and your end-users will get awful response times.

To alleviate the load imposed by both QVS and QDS, there are four solutions:

Schedule reloads when few or no AP visitors are using the system (at night)
Divide the cpu cores between users (QVS) and reload jobs (QDS) e.g. 6 for the AccessPoint and 2 for reloads. This isn't ideal as those two cores may remain unused for 90% of the time.
Install additional cpu's (e.g. cores x 2)
Move your QDS set-up to a separate disk IO-optimized platform. This is the only decent long-term solution. However you'll need a Publisher license for that...

Peter

Re: how to use CPU Throttle ?

mohamed_ahid — Tue, 10 Mar 2015 10:50:31 GMT

and how can i Divide the cpu cores between users (QVS) and reload jobs (QDS) ?

Re: how to use CPU Throttle ?

Peter_Cammaert — Tue, 10 Mar 2015 12:25:36 GMT

Use the CPU Affinity setting.

IMHO this is not the best solution because you'll split cpu resources into isolated pools.

Re: how to use CPU Throttle ?

mohamed_ahid — Tue, 10 Mar 2015 12:45:37 GMT

thanx Peter for answers .But i didn't get the aim behind every setting .

CPU affinity limits the nomber of cores used by QV server and throottling is the % of used CPU .

but all of these options have no link with the reload task . am I right ?

Re: how to use CPU Throttle ?

Peter_Cammaert — Tue, 10 Mar 2015 13:25:19 GMT

Yes, you're right.

And this conflict of interests is the main reason why a Publisher is often migrated to a separate machine.

Re: how to use CPU Throttle ?

mohamed_ahid — Tue, 10 Mar 2015 13:28:48 GMT

OK so in my case i have no settings to perform on QMC ,but maybe improve the reload task plan .

Re: how to use CPU Throttle ?

Peter_Cammaert — Tue, 10 Mar 2015 13:37:44 GMT

You can try with the core split, and see if that helps you any further in reducing the load on your system without angering stakeholders too much.

Re: how to use CPU Throttle ?

mohamed_ahid — Tue, 10 Mar 2015 13:39:19 GMT

how can i do that ?

Re: how to use CPU Throttle ?

Peter_Cammaert — Tue, 10 Mar 2015 13:41:36 GMT

Use the CPU Affinity setting.

Re: how to use CPU Throttle ?

mohamed_ahid — Tue, 10 Mar 2015 13:57:30 GMT

so what i have said juste before is not right . cpu affinity deffine the number of cpu used by the QV server(not publisher) .

otherwise if i choose 50 % of my cpu's in cpu affinity ,implicitly that means that ths other parts will be user by QV publisher( reload tasks) ?

Re: how to use CPU Throttle ?

Peter_Cammaert — Tue, 10 Mar 2015 14:06:55 GMT

Not entirely, there is no implicit "smartness" in the Publisher unfortunately.

To kick the QDS (Distribution service) into the same marching order, you cannot use the QMC because there is no such thing as the nice row of core check boxes just for the Distribution Service (which is a pity)

However (and IMHO this is the real trick) there is a configuration setting called CPUAffinity that only applies to QVB processes. Open C:\ProgramData\QlikTech\DistributionService\Configuration.xml and look for a line that starts with the tag <QVBConfig>. One of the attributes says... CPUAffinity. Set the digits to the inverse of the checkboxes that you marked for the QVS in the Management Console. Restart the QlikViewDistribution Service and...

Re: how to use CPU Throttle ?

mohamed_ahid — Tue, 10 Mar 2015 14:30:17 GMT

but what hapened if i don't have qlikview publisher ?

Re: how to use CPU Throttle ?

Peter_Cammaert — Tue, 10 Mar 2015 15:39:24 GMT

Just the same thing. Not having a Publisher license only means that you don't have a "Management Department" for reload tasks. The main impact of not having a license is in the trigger & distribution feature list, not in the actual reload system. The same QVB process will be started, and it will obtain the QDS configuration which says that some cpu cores can be used for reloads and others should be left alone.

Works like a charm.

Re: how to use CPU Throttle ?

mohamed_ahid — Tue, 10 Mar 2015 17:10:28 GMT

thanx a lot Peter .