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Not applicable

Problems assigning CPU affinity setting for cluster with different CPU counts

My issue is that QMC shows only a number of tick boxes in System -> QlikView Servers -> Performance, but this number is lower than some of my servers have cores (some have more than others) and I can see that QlikView server doesn't use all of the cores but instead follows the number of tick boxes on that setting page.

How QMC decides how many tickboxes it shows and is there a way to force it show them all so that I could get all of the cores in use for all of my servers?

Another option I thought of was to change this setting manually in QVPR, but could not locate the table where this information is stored. Where is this is information stored and can I update it manually?

PS. The number of tick boxes seem to change every now and then. Sometimes there's the lowest amount of cores in the cluster servers, sometimes something in between but so far I haven't had a situation when there was the highest amount of cores.

1 Solution

Accepted Solutions
MVP
MVP

Re: Problems assigning CPU affinity setting for cluster with different CPU counts

Hi Henry,

Indeed, balanced clusters are the best way to work with QlikView, and actually the only supported one. Is not that unbalanced clusters will not work but, as you mention, different hardware (CPU, RAM) in each node will make them more difficult to manage.

The QMC will have likely taken the CPU checkboxes from the first QlikView Server service added to it, or from the first QVS that QMS connects to.

As a workaround, in the QMC, System, QlikView Server, General try to set first the computer with the highest number of cores, so all with less than that will respond as well.

But note that then you will have to add some manual work to decide which apps go where, as long as all the nodes do not have the same capacity, and therefore the user experience will differ from users in one node to those in the other.

Miguel

9 Replies
whiteline
Honored Contributor II

Re: Problems assigning CPU affinity setting for cluster with different CPU counts

Hi.

Is the number of cores in QMC similar to what the OS shows or not ?

MVP
MVP

Re: Problems assigning CPU affinity setting for cluster with different CPU counts

Hi Henry,

Indeed, balanced clusters are the best way to work with QlikView, and actually the only supported one. Is not that unbalanced clusters will not work but, as you mention, different hardware (CPU, RAM) in each node will make them more difficult to manage.

The QMC will have likely taken the CPU checkboxes from the first QlikView Server service added to it, or from the first QVS that QMS connects to.

As a workaround, in the QMC, System, QlikView Server, General try to set first the computer with the highest number of cores, so all with less than that will respond as well.

But note that then you will have to add some manual work to decide which apps go where, as long as all the nodes do not have the same capacity, and therefore the user experience will differ from users in one node to those in the other.

Miguel

Not applicable

Re: Problems assigning CPU affinity setting for cluster with different CPU counts

Thanks for the informative reply. I will try to reorganize the servers and see I can get the maximum number of cores available. For the other point, I'm already assigning servers for the documents manually since I think that is the best way to control the load in our situation. The automatic balancing has its bad moments every now and then, even with identical servers.

UPDATE: I can confirm, everything seems to be working now with this "trick".

Not applicable

Re: Problems assigning CPU affinity setting for cluster with different CPU counts

Hi,

My QMS shows 24 cores, and cluster consist of two servers with 24 and 32 cores. If I unmark two cores from use, how many cores will be used on 32-cores server - 30 or 22?

Even more, if uncheck all but two cores? Two remain? And If check 12 and uncheck 12?

Employee
Employee

Re: Problems assigning CPU affinity setting for cluster with different CPU counts

Hi,

You need to set this to the number of CPU on the smallest box. This would set both to use only 24 cores.

Bill

sudhanshu123
New Contributor

Re: Problems assigning CPU affinity setting for cluster with different CPU counts

Hi Bill,

I have a single node Production environment and my CPU cores are 96 with 2 socket with RAM 1 TB.

so i should get 96*2 checkbox in CPU affinity in QMC under system tab-->Setup--> QVS--> Performance

but i get only 48 checkbox and performance is degraded due to it.

Further i checked there are 4 groups in which CPU cores is divided on Server (of 24 cores Each)

My assumption is Qlik is using only one and therefore 48 processors checkbox is showing and not 96*2.

checked NUMA too.


I am failing to get all CPU cores to work for qlik.

Need help in getting to solution.

Thanks

Sudhanshu Shrivas

Employee
Employee

Re: Problems assigning CPU affinity setting for cluster with different CPU counts

Hi,

Generation 9 of HP servers


Resolution
This issue can be resolved by changing the BIOS setting "NUMA Group Size" to "Flat".
The default setting for "NUMA Group Size" disables QlikView from properly detecting all CPU cores in the hardware, and thereby

From HPs manual on the subject: "Use this option to configure how the system ROM reports the number of logical processors in a NUMA (Non-Uniform Memory Access) node. The resulting information helps the operating system group processors for application use. To set NUMA Group Size Optimization: From the System Utilities screen, select System Configuration → BIOS/Platform Configuration (RBSU) → Performance Options → Advanced Performance Tuning Options → NUMA Group Size Optimization and press Enter. Select a setting and press Enter:
Clustered (default)—Optimizes groups along NUMA boundaries, providing better performance.
Flat—Enables applications that are not optimized to take advantage of processors spanning multiple groups to utilize more logical processors."
Cause
This issue comes from a new BIOS setting introduced in the Generation 9 of HP servers.
A new setting has been added in BIOS that needs to be modified to allow the QlikView services to properly detect all the CPU Cores in the machine.

Bill

sudhanshu123
New Contributor

Re: Problems assigning CPU affinity setting for cluster with different CPU counts

Hi Bill,

we have already performed the setting advised.

after that also we are getting same issue.

"NUMA Group Size" to "Flat".


Anything else,that can be done on this?

Employee
Employee

Re: Problems assigning CPU affinity setting for cluster with different CPU counts

Hi,

Try adding this to the QVS settings.ini file.

MaxCoreMaskHi=-1


Bill

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