How much maximum thread capacity of jmeter command line mode? - testing

I have to test load testing for 32000 users, duration 15 minutes. And I have run it on command line mode. Threads--300, ramp up--100, loop 1. But after showing some data, it is freeze. So I can't get the full report/html. Even i can't run for 50 users. How can I get rid of this. Please let me know.

From 0 to 2147483647 threads depending on various factors including but not limited to:
Hardware specifications of the machine where you run JMeter
Operating system limitations (if any) of the machine where you run JMeter
JMeter Configuration
The nature of your test (protocol(s) in use, the size of request/response, presence of pre/post processors, assertions and listeners)
Application response time
Phase of the moon
etc.
There is no answer like "on my macbook I can have about 3000 threads" as it varies from test to test, for GET requests returning small amount of data the number will be more, for POST requests uploading huge files and getting huge responses the number will be less.
The approach is the following:
Make sure to follow JMeter Best Practices
Set up monitoring of the machine where you run JMeter (CPU, RAM, Swap usage, etc.), if you don't have a better idea you can go for JMeter PerfMon Plugin
Start your test with 1 user and gradually increase the load at the same time looking into resources consumption
When any of monitored resources consumption starts exceeding reasonable threshold, i.e. 80% of maximum available capacity stop your test and see how many users were online at this stage. This is how many users you can simulate from particular this machine for particular this test.
Another machine or test - repeat from the beginning.
Most probably for 32000 users you will have to go for distributed testing
If your test "hangs" even for smaller amount of users (300 could be simulated even with default JMeter settings and maybe even in GUI mode):
take a look at jmeter.log file
take a thread dump and see what threads are doing

Related

How to setup Jmeter test to have a certain throughput?

I am trying to perform a load test, and according to our stats (that I can't disclose) we expect peaks of 300 users per minute, uploading files of different sizes to our system.
Now, I created a jmeter test, which works fine, but what I don't know how to fine tune is - aim for certain throughput.
I create a test with 150 users 100 loops, expecting it to simulate 150 users coming and going, and in total upload 15000 files, but that never happened because at certain point tests started failing.
Looking at our new relic monitoring, it seems that somehow I reached 1600 requests in a single minute. I am testing a microservice, running 12 instances, so that might play the role here for a higher number of requests, but even with it I expected tests to pass. My uploaded file was 600kb. In the end, I had 98% failure.
I reduced the file size to 13kb, at that point, I got 17% failiure.
So, there's obviously something with the time needed to upload the bigger file, but I don't understand what causes 150 thread/users in X loops to become 1600 at the same time. I'd expect Jmeter to never start a new loop with the same thread, unless the original user is finished. That being said - I'd expect tops 150 users in a given minute.
Any clarification on how to get exact number of users/threads running at the same time is well appreciated.
I tried to play with KeepAlive checkbox, I tried adding lifetime of request to 10 seconds (all them uploads get response earlier) - but then JMeter finished the Thread, and I had only 150 runs, no loops.
Thanks!
By default JMeter executes Samplers as fast as it can so there are 2 main factors which define the actual throughput (number of requests per unit of time):
JMeter configuration
Application under test response time
So if you're following JMeter Best Practices and JMeter has enough headroom to operate in terms of CPU, RAM, etc. - you are only limited by your application response time as JMeter waits for previous request to finish before starting a new one.
If you need to "slow down" your test execution consider adding i.e. Constant Throughput Timer to your Test Plan where you will be able to define the desired number of requests per minute

Jmeter test with infinite loop in 'loop controller',constant runtime and 'constant timer'.What are the advantages and how to tune with this approach

I have setup a jmeter script with constant runtime set in runtime controller, infinite loop in loop controller and a constant delay between threads in'constant timer'. How can I perform tuning using this setup? Is there a correlation between 'no of threads', 'rampup time' and 'delay' that should be kept in mind while trying different combinations of these values for performance testing?
Number of threads is basically the number of users you will be simulating. Each JMeter thread (or virtual user) must represent a real user using your application so treat it this way. If you have a requirement that the application must support 1000 concurrent users - stick to this number as the baseline for your testing. With regards to "how much load will my N JMeter users generate" - it depends on several factors like nature of your test, server response time, timers,
Ramp-up is the time for JMeter to kick off the virtual users from point 1. Unless you're doing spike testing you should be increasing the load gradually as if you release all the users right away you will get much less information and in case of gradual increasing the load you will be able to correlate it with increasing response time and decreasing throughput, number of errors, etc. Moreover it will allow to "wamp up" application under test and it will be more ready for the stress
Delay is time the virtual user is "thinking" between operations. Real users don't hammer application non-stop, they need some time to "think" before making the next step. Depending on what the user is "doing" the think time might be different so I would recommend going for Uniform Random Timer instead of the "Constant" one.

jmeter Load Test Serevr down issues

I was used a load of 100 using ultimate thread group for execution in NON GUI Mode .
The Execution takes place around 5 mins. only . After that my test environment got shut down. I am not able to drill down the issues. What could be the reason for server downs. my environment supports for 500 users.
How do you know your environment supports 500 users?
100 threads don't necessarily map to 100 real users, you need to consider a lot of stuff while designing your test, in particular:
Real users don't hammer the server non-stop, they need some time to "think" between operations. So make sure you add Timers between requests and configure them to represent reasonable think times.
Real users use real browsers, real browsers download embedded resources (images, scripts, styles, fonts, etc) but they do it only once, on subsequent requests the resources are being returned from cache and no actual request is being made. Make sure to add HTTP Cache Manager to your Test Plan
You need to add the load gradually, this way you will be able to state what was amount of threads (virtual users) where response time start exceeding acceptable values or errors start occurring. Generate a HTML Reporting Dashboard, look into metrics and correlate them with the increasing load.
Make sure that your application under test has enough headroom to operate in terms of CPU, RAM, Disk space, etc. You can monitor these counters using JMeter PerfMon Plugin.
Check your application logs, most probably they will have some clue to the root cause of the failure. If you're familiar with the programming language your application is written in - using a profiler tool during the load test can tell you the full story regarding what's going on, what are the most resources consuming functions and objects, etc.

LR 12.55/TruClient vusers are stuck in Init state not going to running

I created a TruClient Web (IE) protocol script in LR12.55, when I try to run the script with 50 users, only some would go into running state (in between 25-37) and the rest would stuck in init forever.
I tried to change the Controller -> Options-> Timeout and changed Init timeout from default 180 to 999 however it does not resolve the issue. Can anybody comment on how to resolve this????
TruClient runs a real browser for each vuser (virtual-user), so system resource consumption is higher the API-level testing.
It is possible that 50 vusers is too much for your load-generator machine.
I'd suggest checking CPU and memory levels during the run. If either is over 80% utilization, you should split your load between multiple load-generator machines.
If resources are not fully utilized, the failures should be analyzed to determine the root cause.
To further e-Dough's excellent response, you should expect not to execute these virtual users on the same hardware as the controller. You should expect at least three load generators to be involved, two as primary load and one as a control set. This is in addition to the controller.
Your issue does manifest as the classical, "system out of resources" condition. Consider the same best practices for monitoring your load generator health as you would in monitoring your application under test infrastructure. You want to have monitors for your classical finite resource model components ( CPU, DISK, MEMORY and NETWORK) plus additional sub components, such as a breakout of System and Application under CPU, to understand where and how your system is performing. You want to be able to eliminate false negatives on scalability where your load generators are so unhealthy that they are distorting your test results - Virtual users showing the application is slow when in fact the Virtual Users are slow because the machine in use is resource constrained.

How can JMeter identify what to optimize in a website?

I'm new with website performance testing field and will be using JMeter. After playing with it, I am still having troubles with identifying what to optimize in a website load time?
I'm currently still learning about the load testing - who should I give the performance report to? Developers/Programmers? or Network department? Example of an error I usually get is 502 error or timeouts.
Thanks in advance.
JMeter cannot identify anything, all it does is executing HTTP requests and measuring response times. Ideally it should be you, who takes JMeter raw results, performs analysis and creating the final report highlighting current problems and bottlenecks (and ideally what needs to be done to fix them)
Consider the following checklist:
You load test needs to be realistic, a test which doesn't represent real-life application usage does not make sense. So make sure your JMeter test carefully represents real users in terms of cookies, headers, cache, downloading images, styles and scripts, virtual user groups distribution, etc.
Increase and decrease the load gradually, this way you will be able to correlate such metrics as transactions per second and response time with increasing/decreasing number of users so make sure you apply reasonable ramp-up and ramp-down settings.
Monitor the application under test health. The reason of error may be as simple as lack of hardware resources (CPU, RAM, Disk, etc.). It can be done using i.e. PerfMon JMeter Plugin.
Do the same for JMeter instance(s). JMeter measures response time from "just before sending the request" until "last response byte arrives" so if JMeter is not able to send requests fast enough - you will have high response time without other visible reason.
Website load time is a combination of many factors including the browser rendering time, script execution time, resource download time etc. You can't use JMeter to validate the front end time. You can achieve it using chrome developer tools and other similar tools available for each browser. Refer https://developers.google.com/web/fundamentals/performance/
JMeter is primarily used for measuring the protocol level performance to ensure that you server can process the heavy workloads when it is subjected to real time stress conditions from several customers. It won't compute the java script execution time or HTML parsing time. Your JMeter script should be written in such a way that it emulates the logic of your java script executions and other presentation logic to form the request inputs and the subsequent requests.
Your question is way too open ended and you might have to start with a mentor who can help you with the whole process and train you.
Also, the mindset for functional testing and performance testing are totally different. Lot of key players in the performance area have suggested to measure the load time as part of the functional testing efforts while the majority of the server side performance is validated by the performance team.