I have about 300 users (configured in the thread group) who would perform an activity (e.g.: run an e-learning course) twice. That would mean I need to expect about 600 iterations i.e 300 users performing an activity twice.
My thread group contains the following transaction controllers:
Login
Dashboard
Launch Course
Complete Course
Logout
As I need 600 iterations per 5400 seconds i.e 3600 + 900 + 900 seconds (1 hour steady state + 15 mins ramp-up and 15 mins ramp-down), and the sum of sampler requests within the total thread group are 18, would I be correct to say I need about 2 RPS?
Total number of iterations * number of requests per iteration = Total number of requests
600 * 18 = 10800
Total number of requests / Total test duration in seconds = Requests per second
10800 / 5400 = 2
Are my calculations correct?
In addition, what is the best approach to achieve the expected throughput?
Your calculation looks more or less correct. If you need to limit your test throughput to 2 RPS you can do it using Constant Throughput Timer or Throughput Shaping Timer.
However 2 RPS is nothing more than statistical noise, my expectation is that you need much higher load to really test your application performance, i.e.
Simulate the anticipated number of users for a short period. Don't care about iterations, just let your test to run i.e. for an hour with the number of users you expect. This is called load testing
Do the same but for longer period of time (i.e. overnight or weekend). This is called soak testing.
Gradually increase the number of users until you will see errors or response time will start exceeding acceptable thresholds. This is called stress testing.
Related
i've started distributed performance testing using jmeter. If i give scenario 1:
no.of threads: 10
ramp up period: 1
loop count: 300
Everything runs smooth, as scenario 1 translates to 3000 requests in 300 seconds. i.e. 10 requests per second.
If i give scenario 2:
no.of threads: 100
ramp up period: 10
loop count: 30
Afaik, scenario2 is also executing 3000 requests in 300 seconds, i.e. 10 requests per second.
But things started failing i.e. sever is facing heavy load and requests fail. In theory both scenario1 and scenario2 should be same, right? Am i missing something?
All of these are heavy calls, each one will take 1-2 seconds under normal load.
In ideal world for scenario 2 you would have 100 requests per second and the test would finish in 30 seconds.
The fact that in 2nd case you have the same execution time indicates that your application cannot process incoming requests faster than 10 per second.
Try increasing ramp-up time for 2nd scenario and look into the following charts:
Active Threads Over Time
Response Times Over Time
Transactions Per Second
Normally when you increase the load the number of "Transactions Per Second" should increase by the same factor and "Response Time" should remain the same. Once response time starts growing and number of transactions per second starts decreasing it means that you passed the saturation point and discovered the bottleneck. You should report the point of maximum performance and investigate the reasons of the first bottleneck
More information: What is the Relationship Between Users and Hits Per Second?
In scenario 2 after 10 seconds you have 100 concurrent users which execute requests in parallel, your server may not handle well or prevent such load
Concurrent user load testing sends simultaneous artificial traffic to a web application in order to stress the infrastructure and record system response times during periods of sustained heavy load.
In scenario 1 after 10 seconds you have 10 concurrent users looping through the flow, without causing a load on server
Notice your server may have restriction on number of users requesting only on specific request(s)
We shall be very clear about the Rampup time
Following is extract from the official documentation
Scenario 1 : no.of threads: 10
ramp up period: 1
loop count: 300
In the above scenario 10 threads(virtual users) are to be created in 1 seconds. Each user will loop 300 times. Hence there will be 3000 requests to the server. Throughput cannot be calculated in advance with above configuration. It fluctuates based on the server capability, network etc. You could control the throughput with some components and plugins.
Scenario 2 : no.of threads: 100
ramp up period: 10
loop count: 30
In scenario 2 100 threads (virtual users) are created in 10 seconds. 100 virtual users will send requests concurrently to the server. Each user will send 30 requests. In the second scenario you will have higher throughput (number of requests per seconds) as compared to the scenario 1. Looks like server cannot handle the 100 users sending requests concurrently.
Ramp up time is applicable for the first cycle of each thread. It will simulate delays between first request of each user in their first iteration.
I have a task to run the exact number of requests within an hour, with a given maximum number of concurrency, how do i design that with Jmeter?
For example:
Total number of request: 1000
Run time: 60 mins
Max Concurrency: 15
Meaning my script needs to reach the maximum of 15 requests at the same time at least once, and the rest can be distributed unevenly throughout an hour, and it needs to finish 1000 requests within an hour.
Thank you
You can set the hard limit on the number of requests which JMeter will execute by using Throughput Controller in "Total Executions" mode
You can slow down JMeter's number of requests per minute by using Constant Throughput Timer. If you need to execute 1000 requests in 60 minutes you need to run 16.6 requests per minute, in this case they will be evenly distributed.
If your workload patterns are more complex consider using Throughput Shaping Timer
I am trying to send 1100 requests per minute to my API endpoint for a period of 5 minutes, so in total, I will make 5500 requests to the endpoint.
Based on the above requirement, Here is how I have set up my Jmeter:
It seems like I have misconfigured Jmeter, because in the end I can see Jmeter has made 8401 requests to the API instead of 5500.
What have I missed in the configuration?
Does the "Infinite" check-box need to be checked or unchecked?
The number of requests you're expecting (which is 5500) for this test plan is wrong.
As per your expectation, I think, you are making confusion between the Threads and Requests.
Ramp up is the time in which all the users arrive on your tested application server.
Requests are simulated by samplers but threads are the simulation of users.
According to your test plan:
- Total Number of Threads: 1100 vitual users
- Ramp-up time: 60 (1 min)
- Loop count: Infinite
- Test duration: 300 sec (5 min)
- No of requests/sampler in Test Plan: Unknown, assuming it 1
JMeter Execution:
JMeter will kick off those 1100 virtual users in 60 seconds according to the ramp-up time. So, (1100/60)~ 18 users will be active in every second for the first minute of your test. Each thread/user will execute the requests or samplers you have defined in your test plan hierarchy. As you have defined the loop count to infinite, each thread will execute the requests repeatedly until the test finishes. After 60 seconds, all of your 1100 users will be actively hitting those samplers/requests for the remaining 4 mins.
So the total number of requests you will be able to make through JMeter depends on your application response time.
If the avg response time of your requests is 1 second (assuming you have only 1 requests in your test plan), then you will be able to hit total 264000 (264000/240 = 1100 requests per second) for the last 4 mins (when all of your 1100 users are active) of your tests. You can also verify this accordingly by using Active Threads Over Time and Hits Per Second listeners.
So, Please double check the avg response time of your application or the requests/samplers you are using in your test plan.
If you want to control JMeter's throughput to 1100 per minute, you can use a Constant Throughput Timer at your test plan level and use target throughput value as 1100.
Do not forget to add the count of ramp-down time in your test duration. Yes, when you ramp up i.e. in the first minute generally you get more requests as threads are starting. In your case, your test duration should be 7 mins (60 seconds for the ramp-up 1100 users + 300 seconds for 5500 requests + 60 seconds for the ramp down for 1100 users).
You can also check this thread for more : How should I calculate Ramp-up time in Jmeter.
Please note- The total number of requests is related to throughput, Whereas the number of active threads performing the same activity is related to concurrency.
I am trying to send 1100 requests per minutes to my API endpoint for a period of 5 minutes, so in total I will make 5500 requests to the endpoint.
I don't know how you came with this 5500 number but this is not very correct.
Your setup means that:
JMeter will add 18 virtual users each second for 60 seconds
After 60 seconds pass JMeter will run 1100 users for another 4 minutes
The total number of requests JMeter will be able to make will mostly depend on application response time.
If you want to limit JMeter's throughput to 1100 requests per minute consider using Constant Throughput Timer or Precise Throughput Timer
If you don't want to limit JMeter's throughput but want 5500 executions either:
Set "Loop Count" to 5 (but in that case you might fail to get 1100 concurrent users)
Or use Throughput Controller in Total Executions mode so JMeter would stop after executing 5500 requests
I have set the number of threads and ramp-up time to 1/1 and I am iterating my 1000 records from data.csv for 1800 seconds.
Now given the numbers, I have set the CTT, constant time throughput to 2000 every minute and I expected the average throughput to be 2000/60 = 33.3/sec, but I get 18.7/sec, when I increased the throughput to 4000/60, I still get 18 or 19/sec.
Constant Throughput Timer cannot force threads to execute faster, it can only pause threads to limit JMeter's throughput to the defined value.
Each JMeter thread executes samplers as fast as it can, however next iteration won't start until previous is finished so given you use 1 thread - the throughput won't be higher than application response time.
Also be aware that Constant Throughput Timer is accurate enough on minute level so you can rather manipulate "requests per minute" rather than "requests per second", if your test is shorter than 1 minute - consider using Throughput Shaping Timer
So I would recommend increasing the number of virtual users to i.e. 50.
See How to use JMeter's Constant Throughput Timer for more details.
I guess your application average response time is around 50ms. Which means a single thread can only perform about 20 hits/sec (1 sec / 0.05 sec per hit = 20 hits/sec).
You have 2 solutions:
increase the number of threads to parallelize requests sent,
or make you app response faster (obviously harder).
At some point, when you application can't handle more load, you should see the hits/sec dropping and the average response time increase.
The graph below shows you an example of application which has a steady response time with up to 20 concurrent threads.
There are many questions/answers available here to understand Ramp up time but I want to get something in detail for my test case.
Test Case : Expecting 1200 users per 5 minutes on the home page. So it will be like 5 users/second.
I have set following thread properties :
No. of Threads : 1200
Ramp-up Time - ? [I am not sure what to set]
Loop count - Forever
Scheduler - 300 Seconds[5 Minutes]
Can anyone please help me to set ramp up time for my test case? I am running the test on my local machine.
I want to check that how many users server can handle in 5 minutes. Our expectation is 1200 users.
As per you test case and duration settings, I think, you are making confusion with the Threads and Requests.
In short: You must use Ramp-up as 240 seconds for this scenario.
Let me describe you in details:
Ramp up is the time in which all the users arrive on your tested application server.
Requests are simulated by samplers but threads are the simulation of users.
Please note- The total number of requests are related to throughput, Whereas the number of active threads performing the same activity is related to concurrency.
From your requirements, I assume you want to measure the throughput which is related to the requests/second not the users per second. To achieve this, you can use a Constant Throughput Timer at your test plan level.
Constant Throughput timer allows you maintain throughput of your server (requests/sec). Here requests are samplers. Threads are users/clients which are requesting server using samplers.
You can achieve this by using both "Thread Group" or "Ultimate Thread Group".
As far as I know, it doesn't matter which type of Thread group you are using with Constant Throughput timer, at the end of the test in the results, you will get your desired Throughput which you mentioned in Constant Throughput Timer i.e. if you have mentioned 1200/min in Constant Throughput Timer with "Calculate Throughput based on" value as "All active threads" and there are 3 requests (samplers) in your thread group then JMeter will manage the requests in a way that it will generate only 6.6 requests/sec for each sampler i.e. 1200/min is divided among 3 requests, it doesn't matter whether you are using Ultimate Thread Group or the Thread Group; Throughput timer works in same way for all types of thread groups.
Now as per your requirement: (Using Thread Group):
No. of Threads : 1200
Ramp-up Time - 240 (Since you want 5 users per second, 1200/5= 240)
Loop count - Forever
Scheduler (Duration) - 780 Seconds [13 Minutes]
IMPORTANT:
Thread Group configurations will be the same which you have already mentioned. Number of threads will be the client load which you want to put(in you case it's 1200), duration : (240+300+240), loop : forever, ramp-up : 240 yes when you ramp up i.e. in the first minute generally you get more requests as threads are starting so it is normal behavior. To test your scenario run for exactly 5 minutes, you should test for 13 minutes. Exclude first 4 min and last 4 min of the test as that is warm up time for your test as well as server and last 4 min are warm down period.
Now as per your requirement: (Using Ultimate Thread Group):
Start Thread Count: 1200
Initial delay, sec: 0
Startup, sec: 240 (I assume you want 5 users come to your application for requesting expected samples per second)
Hold Load for: 300 sec (Since you required 5 minutes to test for 1200 users)
Shutdown Time, sec: 240
You can set just like this:
Don't get confuse the Thread number with the number of requests, each thread will create multiple requests for seconds in field Hold Load for.
Rampup is the speed at which users arrive on your application.
The number you put means that once it is reached all threads have been started.
The tiniest it is , the faster users arrive.
So nobody can answer that for you, you need to analyse your traffic.
Regarding the number of threads, 1200 threads might not be the good number, as 1200 users can navigate on application slowly or rapidly.
What you need is add a Constant Throughput Timer to control how much transactions per second you'll be reaching.
You should use the Ultimate Thread Group plugins available in Standard set.
To maintain concurrency the configuration should be like this:
Start Thread Count: 1200
Initial delay, sec: 0
Startup, sec: 60
Hold Load: 180
Shutdown Time, sec: 60
Ultimate Thread Group
Here all the 1200 threads will be generated and up within 60 sec of Startup time(Ramp up time) .Those 1200 threads will be active for next 180 sec, and after that, those threads will shut down within next 60 sec.
So overall duration of the test is 300 sec as you desire. Throughout the Hold Load time(180sec) the requests will be looped.
This ultimate thread group will give you more control over Threads.
Now if you want to control the rate of transactions per second or the number of samples to execute you can use Constant Throughput Timer. Constant Throughput Timer will let you control the flow of requests to be sent. The default "Thread Group" only control the way the users or threads will be generated.It doesn't control the rate of requests to be hit your application.So for this purpose, you could use "Constant Throughput Timer" to control your requests per second. For further detail, you could go through JMeter documentation.