Does reducing capacity of service increases the perdormance ?

[Sai Kiran]

​Hi Team,

We are are using 63 virtual services in performance environment. For one of the stub we have increased the concurrent capacity from 90 to 120 for better performance during load test. We don't see any imporevement but surprisingly we could see decrease in performance.

With Same Load :
Approx. % of transcations response time less that 1 sec with 70 capacity -> 90%
Approx. % of transcations response time less that 1 sec with 90 capacity -> 80%
Approx. % of transcations response time less that 1 sec with 120 capacity -> 72%


Please let us know the best way to calculate concurante capacity for virtual service where we are expecting 1300 transcations per minute.

Best,
Kiran.​

[Sankar Natarajan]

Hi Sai
          Without getting into details about your hardware configuration, I can say that the capacity chosen seems very high. Please refer to the detailed guidelines and a formula to choose the right capacity for your VS.

https://techdocs.broadcom.com/content/broadcom/techdocs/us/en/ca-enterprise-software/continuous-testing/devtest-solutions/10-5/using/using-service-virtualization/using-devtest-portal-with-service-virtualization/deploy-virtual-services.html

regards
Sankar

------------------------------
Sankar Natarajan
Service Virtualization Product Engineering Team
Broadcom
------------------------------

[Sai Kiran]

​Hi Sankar,

We are using Think Scale as 0 for faster responses. Hence we couldn't apply below formulea to calculate concurrent capacity. Please provide your suggestions on below values.


Concurrent Capacity = (Desired transactions per second / 1000) * Average Think Time in ms * (Think Scale / 100)

Desired transactions per second  - 250 Trans per sec
Average Think Time in ms -> 400ms
Think Scale -> 0


Best,
Kiran.

[Sankar Natarajan]

For all practical calculations, you can take the Think Scale as a non-zero value, say 10.

Besides, your initial requirement was 1300 tx/min which is roughly 22 tx/sec. However you have mentioned 250 tx/sec in your last update. Can you check the numbers please.

--

regards

Sankar Natarajan