opensta-users

[OpenSTA-users] CPU usage is showing 100% with 200VUs

[Dev G. <dev...@gm...>]

Hi,

I am using OpenSTA 1.4.3 on Windows XP machine to generate a load of 200VUs
.
I am doing modular testing , it conatins 2 scripts, first script
contains Login info and second script contains application navigation
info. In these scripts i have used 12 variables for parameterization.

All these variable are linked with one .FVR file which contains 1600
data values.

Here is test scenario settings-:

1. Total 200Vus
2. Number of VUs per batch-: 10
3. Batch Ramup Time-: 30 seconds
4. Duration-: 10 mins
5. First Script-: 1 iteration
6. Second script-: 10 mins

Load Generator Machine Configuration.

1. Windows XP
2. CPU- 3.00 GHz, 2.99 GHz
3. 8 GB RAM

Now the problem is CPU usage is showing 100%.

Please suggest any solution to reduce CPU usage.

Thanks
Dev

Re: [OpenSTA-users] CPU usage is showing 100% with 200VUs

[Bernie V. <Ber...@iP...>]

Dev,

> Now the problem is CPU usage is showing 100%.
> Please suggest any solution to reduce CPU usage.

The only thing in your control that I can think of that causes high CPU 
utilization is string manipulation in scripts (the kind that you write). If 
you are doing "load response_info body..." into strings and looking for 
substrings or breaking apart strings to get at substrings, then you'll need 
to either make them more efficient, playback from a server with more CPU 
capacity (OpenSTA capacity scales "ok" on SMP servers), or start using 
multiple servers for playback.

Just out of curiosity, what % of the CPU utilization is User mode?

-Bernie

Re: [OpenSTA-users] CPU usage is showing 100% with 200VUs

[Dev G. <dev...@gm...>]

Thanks for replying Bernie,
If I run script in single step, CPU usage fluctuates between 2-5 %,
In my scripts i am not using Load response_info body or substrings,
I am only using variables and files to send data values in calls.

But now i am running a test (50 Vus, 10 in a batch, 30 secs-Batch ramp
up) with a script, in which i am not using any variable but still its
using 100% CPU, I have noticed as the no of VUs exceed 25, CPU usage
shows 100%,

Still I have not foud any solution, Please suggest if i can try anything else.

Thanks
Dev

On 3/9/07, Bernie Velivis <Ber...@ip...> wrote:
> Dev,
>
> > Now the problem is CPU usage is showing 100%.
> > Please suggest any solution to reduce CPU usage.
>
> The only thing in your control that I can think of that causes high CPU
> utilization is string manipulation in scripts (the kind that you write). If
> you are doing "load response_info body..." into strings and looking for
> substrings or breaking apart strings to get at substrings, then you'll need
> to either make them more efficient, playback from a server with more CPU
> capacity (OpenSTA capacity scales "ok" on SMP servers), or start using
> multiple servers for playback.
>
> Just out of curiosity, what % of the CPU utilization is User mode?
>
> -Bernie
>
>
>
>
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Re: [OpenSTA-users] CPU usage is showing 100% with 200VUs

[Bernie V. <Ber...@iP...>]

>> > Now the problem is CPU usage is showing 100%.
>> > Please suggest any solution to reduce CPU usage.

FYI to the list, Dev and I talked off list and I had a look at the scripts. 
The wait commands generated during the original recording were commented out 
(maybe a couple of minutes worth) and replaced with a handful of 1-2 second 
waits. Script execution was therefore throttled primarily by server response 
time and it makes sense that 200 scripts running in parallel would consume 
the majority of his server's CPU capacity assuming the system under test 
could service the high request rate without slowing down considerably.

-Bernie
(www.iPerformax.com)