Qlik Sense Scalability Tool running at 50% Capacity in 2 socket 96 Core server

[khennessy]

We are running the 5.2 version of the scalability tool in a server that has 2 sockets and 96 cores. We are scaling up 250-500 concurrent users in the server and seeing the tool only use HALF of the CPU.  In a 1 socket 48 core environment, the tool is performing BETTER and reaching higher capacity.  

There is nothing online to indicate why the tool cannot use the full capacity of the server and was wondering if anyone else has run into this issue or has any insights on why the tool is behaving this way. 

This is inhibiting us from scaling an appropriate amount of concurrent users.  

[plusselmann]

During our scalability testing we found out that platform was behaving fine but the issue asbthe VM running the QS scalability tools.
As this was the bottleneck, had to run 2 VM with scalability tool in parallel to really stress the server.

[Jens_Argentzell]

Hi,

The tool is limited to 1 processor group and that is most likely why you see only half the capacity utilized. In a server configuration with NUMA disabled this means that the tool is limited to 64 cores. But if NUMA is enabled, the processor group will be limited to one socket and thus the tool will only use 1 socket and half the cores.

It is hard to predict exactly how much CPU is required for simulating a certain amount of users as it is dependent of scenario and think times etc. But the 1 processor group limitation means that if you see all cores of one processor group or socket saturate you need more instances to simulate that load. 

Best regards,

/Scalability team