Apache Jmeter - need thread scope variables - websocket

I am trying to run websocket load testing and find I need access to variables defined at thread scope.
Specifically, I need to randomly generate a UUID to be used as a pseudo-user ID. Our API requires this to be passed as a parameter with each request :
send auth request with the UUID
- this will create a user account keyed on system information
wait for response
loop sending sync/initialize with UUID
The UUID is the app id. I can randomize that easily with a User Defined Variable via the UUID function, however, user defined variables are apparently calculated once at the start of the test whereas I need them to be generated at thread group scope. Is there a way to do that? If now, how can I achieve this?
In other words, I need a randomly generated UUID for each thread (acting as a user) which is accessible to each sampler in the thread group.
Thanks in advance!

You can use a Beanshell preprocessor for the very first sampler which needs this UUID as shown below.
vars.put("uuid", "${__UUID}");
All other samplers in the thread group for the user/thread will have the same UUID and it can be accessed by using ${uuid}.

I do faced this issue during the load test, the solution is
Use epoch time (ms) and append UUI value. This is the solution because epoch time never be same , if two transactions are issued at the same time, UUI changes every time. So whenever you run the test, these values should be unique.Below is the code for reference
epoch Time:${__javaScript(Math.round(new Date().getTime()))}
UUID: ${__BeanShell(UUID.randomUUID().toString())}
Combination is :${__javaScript(Math.round(new Date().getTime()))}_${__BeanShell(UUID.randomUUID().toString())}

Related

Jmeter ,Way to call rest API for every 3minutes to get Auth token

I am working on setting up a way to do a performance test for the rest API's using Jmeter which includes token expiry for every three minutes.
1.)Currently, I created two thread groups one for making a call to get "access_token" and setting into the property using Bean shell assertion setProperty, to be used in other thread Groups.
2.)I could see Second thread group can access the value set in the first step.
But my goal is to execute the first thread group every 2min 30 seconds continuously so that the second thread group can get the new token every 2 min 30 seconds.
I tried a constant timer, but didn't seem to work is there any way to do this or any other timer to use to achieve this token refresh?
Thanks in advance
The Constant Timer should work, but be aware that it creates a delay before each Sampler it it's scope so it might be the case your setting it up wrong, you can use i.e. a Dummy Sampler and put the Constant Timer as a child of the Dummy Sampler, this way your HTTP Request to get token will be executed, followed by the delay defined in the Constant Timer, followed by the Dummy Sampler, et.c
Example setup:
You might find Flow Control Action sampler easier to use
Also be aware that starting from JMeter 3.1 you're supposed to be using JSR223 Test Elements and Groovy language for scripting. Moreover it's not required to write any code, you can go either for __setProperty() and __P() functions combination or for Inter-Thread Communication Plugin

How to Capture Jmeter test metrics like test start time, end time, number of users and pass it to rest API call

I am new to JMeter. I have two scripts one script is web and another is a rest api call which posts metrics to server. Both the scripts are working fine. Now i wanted to implement a scenario.
Web Script should run first once the script is completed i need to capture test metrics like start time, end time, load rate (No.of threads), Pass or fail save to a variable and pass these values to the rest api call which will then run and post the metrics to the server.
Any help is appreciated
Start time - can be obtained as ${TESTSTART.MS} JMeter pre-defined variable
End time - can be obtained via __time() function, if you call it somewhere in tearDown Thread Group it will report the time when all the main Thread Group(s) are done
Number of threads - it's a kind of weird requirement because its you who define the number of virtual users. Anyway, you can obtain it at any moment of time using i.e. __groovy() function like:
${__groovy(ctx.getThreadGroup().getNumberOfThreads(),)} - returns the number of threads which are active currently
${__groovy(ctx.getThreadGroup().getNumThreads(),)} - returns the number of threads which are defined in the Thread Group
As you are planning for the given scenarios you need to do following things.
1) You need to user jp#gc listeners to measure the results in (response time, threads per minute/seconds, hits per second and many more)
You can find the list of listeners here >> https://jmeter-plugins.org/wiki/GraphsGeneratorListener/
2) You need to implement the test plan using regular expression extractor for taking values from the response requests which you can store in the variables and later pass on to the dependent requests. for documentation visit https://jmeter.apache.org/usermanual/regular_expressions.html
For general understanding you can go through the jmeter official documentation
https://jmeter.apache.org/usermanual/get-started.html
I hope it will help you

Jmeter - running multiple threads using different author token

I have created a thread with three steps to:
Access token request: it generates a token to be used in step three. This token is stored in a property
${__setProperty(accessToken,${accessToken})}
Logon Get request to hit a url
Logon Post request, pass some data to the url and I have set the Authorisation header using the Bearer + accessToken (the one generated in first step.
Running a single thread it works, perfect; but when I increase the number of threads, the 3 steps are not running in sequence, maybe I have some Access token before the first Logon Post and I see the token this one is using is not the token generated in the first step, it is the last one generated.
If I set a rump time longer of the total execution time it works, but then I cannot run several threads on parallel.
How can I configure the script to run the threads using the correspondent token generated in step 1 in each Post? How can I different properties or variables to store the token of every thread and use them?
Thanks.
Your issue is that you are mixing Variables and Properties.
In summary, as per functions reference:
Variables are per Thread
Properties are shared accross Threads
So don't use setProperty, just use ${accessToken}
Use property only when you want to effect all threads. Otherwise you can save variables in other variable as in User_Parameters where you put new variable name the value can be a different variable as ${accessToken}
filling in the Variable name in the 'Name:' column. To add a new value to the series, click the 'Add User' button and fill in the desired value in the newly added column.
Values can be accessed in any test component in the same thread group, using the function syntax: ${variable}.

Jmeter. How to pass a variable generated by each user in thread to second thread users?

Good day, guys!
What I attempting to do is perform a clean logout for all users after test stops running via duration restriction.
In my case, when user logs in, he gets unique session id parameter that makes it impossible to log with same user from different tab/browser/place, so I need to be sure that user is not blocked after my test completes.
Lets say I use 100 users for a test.
My test looks something like:
Login (get session id)
do stuff
do stuff
Logout (terminate session)
It works fine when I use a constant set of loops, but when I run test with duration, for example, 600 seconds, test stops in the middle after time runs out and my users are blocked until their sessions expire by timeout.
I tried to create a second thread which also contains 100 users and only a logout HTTP sampler, passed and used session id variable to it as described in article https://www.blazemeter.com/blog/knit-one-pearl-two-how-use-variables-different-thread-groups but it seems that my second thread receives only a last session id value so it basically logs out 1 user 100 times, but I need to log out 100 users 1 time.
Does anyone now how to store multiple values of a variable and use them in correct order in other threads?
Not a programmer, just a manual tester with some extra responsibilities.
Thank you.
JMeter Variables are local to each thread, JMeter Properties are global for the whole JVM so if you're passing variables between thread groups make sure you add current thread number as a prefix (or postfix) for the generated property, something like:
In the first Thread Group define user-specific property using __setProperty() and __threadNum() functions combination:
${__setProperty(foo_${__threadNum},${YOUR_VARIABLE_HERE})}
In the second Thread Group get user-specific property using __P() and __threadNum() functions combination:
${__P(foo_${__threadNum},)}
Replace foo with the property name of your choice
Replace YOUR_VARIABLE_HERE with the name of the relevant JMeter Variable
Demo:
See Apache JMeter Functions - An Introduction to get familiarized with JMeter Functions concept.

How to send multiple requests simultaneously with dynamically changing resource in jmeter?

I need to send multiple post requests simultaneously. And the problem is that transaction id in url should always be unique.
I added Synchronizing timer to send requests at once and added BeanShell PostProcessor to increment transaction id after request is sent.
But this works only if requests are executed one by one. How to increment transaction id if I need to run requests all at once?
Just use __counter() function in "global" mode like ${__counter(FALSE,)} instead of manually incrementing the "txnId" variable:
Demo:
See How to Use a Counter in a JMeter Test article for more information on generating incremented numeric values in JMeter.
Going forward remember that you need to implement some form of inter-thread communication to ensure that the same variable is not updated by 2 threads at the same time.

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