Hello Manav,
The following documentation article may be useful to you: Load Testing: Checking Whether Server Supports a Certain Number of Users
There is no single configuration to achieve the test objectives you have described. In general, you will want to use a Stepwise load profile so that you can see at what point performance issues may occur. A good starting point is to identify what kind of peak load your application currently receives. If such data is not available, you may make an educated guess based on the amount of concurrent load you may need to support.
For example, to find the crash point for my application, I started by running a test for 100 VU, then 500 VU, then 1000 VU and so on. My 100VU test passed with no problems. My 500VU test also passed, but I noted that Page Load Time was much worse. My 1000VU test failed, and the graph is shown below:
I can see that errors occurred, but not until my load had ramped up to 1000VUs. Therefore, I ran another test for 1500VUs:
In this test, I can clearly see that the server began to give me errors around 1100 users. I then consulted the Details report to see exactly what errors occurred. This article on Analyzing Results may also be useful to you.
Hope this helps.
Hi Ryan,
Thank you a lot for such detailed reply!
Could you please extend it with the information about the used hardware? (CPU, memory, OS, disk type (SSD, disk array, ...), maybe motherboard/chipset, etc that is relevant) Was you able to simulate 1.5k VUs on the single system or used distributed system?
This information can be useful to be able to make an initial estimations about hardware requirements and possible expectations for this or that planned load test.
Hi Alex,
The process I outlined in my post was intended to be a guide for how you might approach stress testing. My own test conditions are unrealistic, as I used LoadComplete to test a locally hosted application, so network was not a consideration. As such, I was generating the load and hosting the app on the same machine (a laptop — Intel i7-3540M 3.0GHz, 8GB RAM, SSD — with an ASP.NET app hosted on IIS 7.5). I was actually surprised this environment could handle as much load as it did.
Hope this helps.
Hi Ryan,
I never was able to be even close to your load figures...
In my case with a laptop Intel i7-4720HQ 3.5GHz, 8GB RAM, processor gets 85-100% load for 7-9 virtual users.
> I used LoadComplete to test a locally hosted application
I am not sure that this is too bad as I still don't know how to measure network delay without the tools like AlertSite or some special setup that makes it possible to measure the time spent in the network. (I will appreciate any piece of advice or experience in this area.) So, I consider load testing within the well configured local network not a bad approach to minimize the impact of the uncnown network delay time.
Hi AlexKaras
When LoadComplete — or more specifically, the Remote Agent Service that is used to generate load — is running a test, it will consume all available CPU resources. (As a side-note, we are looking to change this behavior in the future to be more responsible with CPU resources.) Monitoring the CPU on the machine that is generating the load will not provide a useful metric. To determine load capacity on a local machine, I would be looking to see how the web server responds to all the requests that are generated. In my example above, I determined load capacity by looking at server responses. When the server was overloaded, I started to see HTTP status codes of 500 Internal Server Error.
Does this help?
