In JMeter, timers are used to have variable time gaps between requests.
But how can I bring various time gaps between users , ( the concept is pacing)?I hopeI am clear in asking .Please explain. Thank you
You can use "Test Action" Sampler for achieving Pacing.
Related
I've to execute a test where one transaction can have multiple-lines (Eg: orders placed by different users in the real world where every user can have different cart size). In order to achieve this I have a products list and I need unique product at every occurrence. I have used a code similar to this "https://www.perfmatrix.com/jmeter-parameter-setting-unique-each-occurrence/" and I was able to achieve unique each occurrence. But the problem is when I am using a throughput controller and constant throughput timer I am not able to achieve desired TPS whereas hardcoded payload with various lines (with throughput controller and constant throughput timer) leads to desired TPS. Do we have any other options to achieve this?
Beanshell Sampler might be the root cause of the problem, according to JMeter documentation you should be using JSR223 Test Elements and Groovy language for scripting since JMeter 3.1 because using Beanshell is a some form of a performance anti-pattern, check out Apache Groovy: What Is Groovy Used For? article for more details.
Another possible reason could be test data itself, for example request A is "light" and returns data in less than one second due to its request parameters and request "B" is "heavy" and returns data in more than 5 seconds.
Throughput of 100 requests A and 100 requests B will be different so you might need to add more threads.
I have read the user guide, here or on Blazemeter blogs regarding usage of flow action to implement dynamic pacing in Jmeter script with help of a JSR223 timer. I wanted to check if I can use JMX dummy sampler to implement the same JSR223 timer?
Does it really impact performance if using Dummy Sampler vs Flow Action in performance test scripts as both are samplers only. Please advise and any support link would be appreciated.
Impact performance of what?
"Pacing" is yet another approach to control the number of hits per second by slowing down the requests for whatever reason (not to overwhelm the application, send desired number of requests per second, etc.)
Any implementation of "pacing" is "killer" of the performance because it adds a pause between iterations instead of starting new iteration immediately so your question doesn't make a lot of sense. If you want to use the most resource efficient solution - you need to either share your implementation details for these 3 approaches or better measure it yourself using a profiler tool
If you're looking for a easier/better way of sending requests at constant rate instead of implementing the "pacing" I would rather recommend considering using of the following test elements:
Constant Throughput Timer
Precise Throughput Timer
Throughput Shaping Timer
I'm about a week into learning JMeter and I've run a few test scripts which generate a summary.csv which contains your standard ; Samples, Average, Median etc...
[My Question]
I was wondering if there was a way to add a threshold for the summary.csv so if Average time is higher than x amount of milliseconds, then the user will be informed that the specific result was slower than expected. (Maybe this can be displayed on the summary.csv, I'm not sure what my options are tbh on how to output this)
I am aware that we can use assertions (specifically duration assertion) through the test script but the issue I have with assertions is that it stops the test once an assertion fails, stopping it from generating a summary.csv
Thank you for any input/opinions you guys have :) It is much appreciated!
Have a great day and stay safe everyone!
They are there already and they're controllable by the following JMeter Properties:
jmeter.reportgenerator.apdex_satisfied_threshold
jmeter.reportgenerator.apdex_tolerated_threshold
there is also a property which can apply thresholds to specific samplers or Transaction Controllers: jmeter.reportgenerator.apdex_per_transaction
Just declare the properties with the values of your choice in the user.properties file and next time you generate the dashboard its APPDEX section will reflect the thresholds.
More information: JMeter HTML Reporting Dashboard - General Settings
I have created a test plan in Jmeter and ran it for 10 users, it has run successfully without any error, as in the below screenshot of the listeners which I have added in my test plan.
In the above listeners, how may I come to know that the values of these fields Standard Deviation, Throughput, Median, Error% calculated as expected Or is there any ideal/expected/benchmark values of the above fields through which I compare and found that my test plan work as standard. Moreover how may I able to explain that the performance of my test plan is fine/good/better or best
Please suggest me thanks
It sounds like you don't really understand what you're doing so I would recommend starting with i.e. Performance Testing Guidance for Web Applications e-book.
With regards to the "values" - we have no any idea whether the "values" match your expectations. There are no any reference "values", normally your project should have non-functional requirements or SLAs which should define maximum response time or minimum number of hits per unit of time.
Check out JMeter Glossary to learn what the "values" mean.
If you don't have NFRs or SLAs defined you still can perform a stress test like:
Make sure that your JMeter test behaves like a real browser, at least I fail to see:
HTTP Cookie Manager
HTTP Cache Manager
HTTP Header Manager
You should be running your test in command-line non-GUI mode
Start with 1 virtual user and gradually increase the load until
you see the saturation point
you start seeing performance degradation
This way you will be able to state what is the maximum number of users you system can support without issues
In JMeter when I right click Thread/Controller I have an option: Add Think Time to children feature , when I click on it I get after every Sampler Test Action Pause with Uniform Random Timer with Random Delay 100 and Constant Delay 1000.
I didn't find in documentation any reference to it and why/how it should be used.
Is it configurable and how? is there a special case for it or should it be used for loading best practice ?
Also you can add several times think times I'm not sure is it on purpose (add more delays after request)
EDIT
Configurable using jmeter.properties:
# Default implementation that create the Timer structure to add to Test Plan
# Implementation of interface org.apache.jmeter.gui.action.thinktime.ThinkTimeCreator
#think_time_creator.impl=org.apache.jmeter.thinktime.DefaultThinkTimeCreator
# Default Timer GUI class added to Test Plan by DefaultThinkTimeCreator
#think_time_creator.default_timer_implementation=org.apache.jmeter.timers.gui.UniformRandomTimerGui
# Default constant pause of Timer
#think_time_creator.default_constant_pause=1000
# Default range pause of Timer
#think_time_creator.default_range=100
When it comes to web applications load testing the idea is to represent a real user sitting in front of computer using a real browser as close as possible.
Well-behaved JMeter test needs to mimic this real user with all its stuff like:
headers
cookies
cache
embedded resources
AJAX requests
etc.
The purpose of using Timers in JMeter tests is simulating real users "think times". Users don't hammer application non-stop, they need some time to "think" between operations, fill forms, type comments, even clicking on a button or link takes some time. So if you are testing if your web application supports X users each JMeter thread must act like a real user so you need to add reasonable think times using Timers. There is no "best practice" or "known good values", it depends only on your web application specifics. See A Comprehensive Guide to Using JMeter Timers for more details.
This feature is made to simplify addition of Think Times, the way it adds them to plan lead to pause between every sampler while if you just add a Timer it will be scoped and thus be applied before all samplers in scope.
As it's a helper, it adds default Pause of 1 second that are configurable by tuning the properties you have mentioned and which are documented :-) :
http://jmeter.apache.org/usermanual/properties_reference.html#timer
You can adjust:
The type of Timers you want to create
The constant and variable pause range
You can even create your own class that would work differently.