Calculation of Vuser per Load Generator

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Calculation of Vuser per Load Generator

3 posts from 3 voices

Started 1 year ago by Pamela
Latest reply from Brandan

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Pamela
Member
Reputation:297

- Without Concurrent groups?
(indicate which)

5. Which LoadRunner/PerformanceCenter feature (FPs) or service packs are you using?
(9.10.0.0)

6. VuGen Recording - are you using Old or New Recording Engine?
(indicate which)

7. You must list here the specific Licensed Vuser type for your specific issue AND the license amount you have for your Vuser protocol(s) - per the example below (Unlimited, Permanent, N/A, etc. are not options) If you do not know because you are using a cracked version, list as "CRACK".

HP LoadRunner SOA Protocol Bundle 2500 Virtual Users SW LTU
HP LoadRunner SAP Protocol Bundle 2500 Virtual Users SW LTU
HP LoadRunner Web Multimedia Protocol Bundle 2500 Virtual Users SW LTU
HP LoadRunner Remote Access Protocol Bundle 2500 Virtual Users SW LTU

8. Is your support/maintenance contract current and active?
( Yes )

9. What platform(s) (PCs) and Operating Systems (Windows-XP, etc.) are being used for load generators and controllers? Include version and service packs (SP1 or 2, etc.)
Load Gens' Windows XP SP2
Controller VMware 3.5

10. If you have filed a service request with HP/Mercury, what have they told you at this point with respect to your issue?
(NA)

I recall a post on this site that outlined a procedure for calculating the number of users that could be run on a load generator (using HP Load Runner v 9.1). Is it possible someone has that post and could direct me to it.
I know we measure amount of system resources (e.g. Processor, memory, disk,) used by the application under test.

Posted 1 year ago #
Cyril
Member
Reputation:372

Search for posts by James Pulley - this sounds like information he might have posted.
For further assistance please read and follow:

http://www.sqaforums.com/showflat.php?Cat=0&Number=117445&an=0&page=0#Post117445

Posted 1 year ago #
Brandan
Member
Reputation:227

You look like your license is falling within the corporate model range for a user population of 50K between 5-12% concurrent and active.

As to Load Generators, there is capacity question and then there is best practice. If you are testing an application with that much risk, go ahead and follow the best practices. The cost of a generator population is going to be a gnat's eyelash as compared to the cost of your LoadRunner license.

Here are your rules of thumb:

    * No Virtual User Load on the LoadRunner controller host
    * Not less than three generators (primary load on two plus a single virtual user of each type on the third)
    * Always have a hot spare, hardware matched, to use as a cannibal for failures or to press into service to rebalance load.
    * All hardware matched, max memory (4GB for 32 bit CPUs and OS's - Load Generators are 32 bit animals), dual or quad core at this point, 200GB HD min.
    * Windows XP Sp3 on generators. You don't want the overhead of Server or Vista to eat into your CPU or Memory resource.
      [Intelligent network adapters, get them with TCP offload engines and SSL accelerators if possible. This takes a lot of interrupt service load off of the core CPU. You can extend this analogy to the video cards and the disk subsystem as well. Get co processed video and intelligent disk adapters, with the goal of leaving the core CPU to the task of running the OS and the MDRV agents
    * Run with blank screen saver on all load generators

I always recommend a client purchase at least seven hardware matched solutions, accounting for the one in seven hardware failures in a given year. Take on for the controller, a second for the "control" generator, a third for the hot spare, which leaves four for your primary load.

Given your projected load in the 2500-10000 (if you run all virtual users in one test) range, you might consider more machines. I tend to be very conservative with my virtual users as I never want to have a capacity issue in my test equipment color the test results and then have to run the test over. If you looked at a 10K test, with 500 virtual users per box (you could probably go to 1000-1500 depending upon the virtual user without issue), then you are looking at 20 boxes for primary load (+1 Controller, +1 Hot Spare, + 1 control). Even if they were 1K apiece, which is extremely pessimestic, you are looking at a very small amount versus the cost of your Load Runner license, the labor and the expertise to make this test execute correctly.

Could you get 1K, 2K or 5K on one host? Potentially yes depending upon the size and complexity of the virtual users. However history suggests that you will have a substantial number of issues related to your decision from a process, a test results integrity and results defensibility basis. Plus lacking a control factor is generally considered not best practice for testing whether you are testing a fuel injection system or a complex piece of software.

Posted 1 year ago #

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