JMeter Thread Communication Pre and Post Process delay - performance

My Test Plan have 3 Scenarios,
Submit Quote
Check Status
If Status Complete get Quote Details.
If I keep all these 3 scenarios in one thread then CTT is not putting constant throughput, when I remove create 2 thread 1 for Submit and other for Status and Get Details I am able to maintain CTT, but my 2nd and 3rd Scenario volume drops almost 50%. As I have dependency on 1st step I am using Thread communication and not sure how I can either get CTT in one thread or get same volume from 2 different threads.

Constant Throughput Timer is useful to shape the load where there is > 1 test iteration. If your thread group has only one iteration consider using Throughput Shaping Timer instead or play with ramp-up and thread number values. It is recommended to have only one instance of the CTT in your Test Plan as it's rather resource consuming by nature.
If your scenario assumes different throughput for different thread groups you can add a CTT per Thread Group (make sure that you select All active threads in current thread group (shared) in "Calculate Throughput based on" dropdown
If ITC test elements are throttling your test below desired throughput value consider using
__setProperty()
__property()
__threadNum()
functions to implement inter-thread communication instead. JMeter Properties are global, can be accessed from different thread groups and persist all the time while JMeter is running.
See How to use JMeter's Throughput Constant Timer for details.
If above information is not enough try to elaborate your query and include i.e. thread numbers, target throughput and what kind of information needs to be shared across thread groups.

Related

How to generate number of requests per second for one user

I am trying to configure a test for signup-login with invalid credentials imitating bruttforce attack. However, I want to make requests as a single user.
So the scenario is the next:
Request to sign up with valid params;
Attempt to log in with invalid params in a loop.
I am adding throughput timer but then I need to set up a high number of threads to generate for example 1 request per second.
How can I set exactly one user and run only one request per second in a loop?
UPDATE - SOLUTION
Everything was rather simple but still strange for me.
Maybe someone will face the same problem.
To get a number of requests per one user throughput timer should be placed not inside the controller but inside the thread itself.
To achieve Target Request Per Second use Throughout Shaping Timer : How to use Throughput Shaping Timer
JMeter Plugin link : Download from here
Few Important Notes:
JMeter threads of Thread Groups in scope of the Element will be
stopped when RPS schedule finishes.
Provide enough working threads for your RPS, JMeter timers can only delay threads (and limit RPS). You may pair this plugin with Concurrency Thread Group using Schedule Feedback Function to dynamically maintain thread count required to achieve target RPS.
If you're using versions of JMeter lower than 3.3 and if you have RPS that lower at the end of test, make threads to lower also. Оtherwise you'll have a spike in last second.
Avoid using zero RPS value as start of test, this produce spike also
Avoid zero RPS during the test, this may lead to nasty effects
Now, practical example showing 1 RPS for 1 User:
You might want to reconsider the location of the timer, it obeys JMeter Scoping Rules so it gets applied to all Samplers which are in your Thread Group.
If you want to apply it to only one - make it a child of the relevant sampler.
Also be aware that Constant Throughput Timer is precise enough on minute level so you might want to switch to the Precise Throughput Timer

Distribution of throughput among different thread groups in jmeter

Below is the actual volume i need to achieve in 1 hour of my jmeter load test.
Required Request/second=0.14 (520/3600)
Hence i have Throughput shaping timer with Start RPS and End RPS as 0.14 for 3600 Sec.
i have 2 thread groups.
Thread group 1 has transactions- Launch and Login.
TG1
**Thread Group**
Launch
Login
Thread group 2 has Action1 and Action2 transactions.
TG2
**Thread group**
**Action1**
**Action2**
Having all these under one thread group ,i can achieve anticipated load using combination of No Of threads required and Throughput COntroller.
But here my requirement is ,i have transactions in different thread groups.
Can anyone tell my how can i distribute the throughput for two different Thread groups.
You should be able to apply the same approach as for the single Thread Group to any amount of Thread Groups.
Throughput Controller obeys JMeter Scoping Rules so if you place it to be as a child of the 2nd Thread Group - it will not have any impact on other Thread Groups
Also be aware that in some cases it's easier to use Switch Controller for requests distribution, check out Running JMeter Samplers with Defined Percentage Probability article for more details.
If you are targeting for specific number of requests per second the best approach is to use
bzm - Arrivals Thread Group
It automatically adjusts userload and maintains target RPS levels.
You are targeting 0.14 request per second that means 8.4 requests per minute so in arrivals thread group enter 8 arrivals per minute (It accepts only whole numbers so you can round off to 8 or 9)
Enter Rampup rate steps and maximum number of concurrent users (This helps to limit max number of users )
And inside the thread group you can use throughput controllers to control your transaction executions as shown in above screenshot.
Please refer to the sample test plan from the link ( you can find it in details section of the report).

Issue with Jmeter Constant throughput Sampler

I have Jmeter script with two thread group with two different API calls. My requirement is Thread Group 1 is to achieve 10 throughput per min and Thread Group 2 is to achieve 50 throughput per min. So I used constant throughput timer in the script.
When I run the test with above setting, thread group 2 is not achieving the expected throughput(50 per min) instead its only achieving the whatever the throughput defined in thread group 1's constant throughput timer(10 per min). I have kept 'this thread only" setting in the Timer.
Am I missing anything or some other setting needs to be done to achieve my requirement?
Your two groups are having different threads but you have also used Interthread communication Pre and Post processor's which works on FIFO concept as shown below.
For more info check this
Until its FIFO you cant achieve it. Instead, use properties to set the variables and get them in other thread. Check this.
Hope it help.

Increment user number with JMeter GUI

I would like to execute a loop of HTTP requests with an incrementally number of users.
For example, I want something like that :
1st loop : 1 user
2nd loop : 2 users
3rd loop : 3 users
...
Is that possible with the JMeter GUI ?
Thanks in advance !
You can achieve this effect by using the Stepping thread group plugin
You can gradually increase the number of concurrent users in JMeter. But not in the way you are actually asking ie, every loop / iteration!
Simply - You can not change the thread count within the test once the JMeter test has started running . But you can use variables for the user count and supply to the test before the test starts.
To gradually increase the user count, you can use any of the below thread groups
You can use the regular thread group, ramp-up period. 100 users and 1000 seconds ramp up period, will add 1 user every 10 seconds.
Stepping Thread Group
Ultimate Thread Group
Actually JMeter doesn't allow this, however you can work it around using different approach, for instance if you stick to Requests Per Minute rather than to Virtual Users.
You can use Constant Throughput Timer to set desired initial throughput (i.e. N requests per minute) and increment it by desired factor each Thread Group iteration.
Despite word "Constant" in its name the throughput doesn't have to be constant, it can be a JMeter Variable or Function or JMeter Property.
Reference material:
How to use JMeter's Throughput Constant Timer
Beanshell Server
Throughput Shaping Timer - an advanced version available via JMeter Plugins, has some extra scheduling capabilities.

Jmeter thread groups

I have entered 500 to be the number of thread group and ramp up time to be 120 seconds but when the report is generated,the virtual users count is only 15 or in composite graph-active threads over time is raised to near about 12. So I am bit confuse active threads counts. Because the data(threads) or numbers that I filled in test plan before test is different and after result is different. What about scaled values in graph?and x10?Something related to threads?
Each JMeter thread representing a virtual user after initialization starts executing samplers upside down (or according to the Logic Controllers).
If thread doesn't have more samplers to execute and no more loops to iterate it's being shut down. It looks just like your case. See Max Users is Lower than Expected article for more detailed explanation and workaround.
Usually people set Loop Count to "Forever" and use Runtime Controller to so test could finish in designed time. Another option is using i.e. Ultimate Thread Group available via JMeter Plugins which provides convenient way of defining a load scenario.

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