by eValid » Wed Jan 28, 2009 7:25 am
Thanks for asking. Those are tough questions to answer simply. We'll try to give some guidelines based on our experience. But remember: "Your Mileage Will Vary"...
The main issues you need to address are the size of the eValid footprint, and the machine input/output capacity.
(1) Memory/RAM Requirement
In LoadTest mode eValid playbacks are done with the evalidT (THIN) version, which is as small an eValid browser as we can make it.
The starting RAM is ~20MB per instance. Depending on how many URLs are in the script, and how many times the playback is repeated, and the duty cycle of the script, this footprint can grow to above 50MB.
In Windows all of the processes will eventually run, but you surely want to avoid swapping. Once the machine goes into swapping mode it is pretty uch "all over with".
Machines running 32-bit Windows have 3 GB of RAM address space, so you should plan on using all of that.
We usually plan on 125 eValids per machine, to be safe and conservative. The maximum we've seen on a 3 GB of RAM machine is 230, but at that point the machine is "red lined".
(2) CPU Adjustments
Out of the box Windows machines don't usually run more than 15-20 simultaneously browsers happily.
There's a set of adjustments you need to make:
[url=http://www.e-Valid.com/Products/Documentation.9/Loading/machine.html]
Machine Adjustments[\url]
These manipulate the amount of heap space and the size of the virtual swap spaces.
(3) Input/Output Capacity
Some customers switch to a 1 Gbps LAN rather than the 10/100 Mbps.
But usually it is the I/O capacity of the machine that is the limitation.
In other situations, we have had customers deploy machines with extra high-end I/O cards -- to match 1 Gbps LANs.
(4) Our "nominal machine" is a Cor2 Pentium IV at 2.5 GHz with 3 GBytes of AM, and with the CPU Adjustments done.
Hope this helps you out.
Remember, "Your Mileage Will Vary"...
The eValid Team
