Hi I am new to JMeter and I do know how to perform load tests using JMeter. I tried to figure out how a stress test or a capacity test is performed via JMeter. Is it by gradually increasing threads in JMeter we can determine when performance hits are arise and get that threshold and run tests above the threshold. Does it make a stress test then?
Confused in how to perform a stress test and a capacity test with Jmeter tool.
JMeter is very flexible and load scenario can be established in multiple ways. Out of box there are following test elements available:
Thread Group - where you can set
Virtual Users Number
Ramp Up Time
Iterations count
JMeter acts as follows: each samplers are being executed upside down with each thread representing virtual user. When thread has no more samplers to execute and no more iterations it is being shut down. For ramp-up bit: by default settings JMeter tries to kick off all the threads as fast as it can but you can configure it to simulate increasing load. I.e. if you have 30 users and 30 seconds ramp-up time JMeter will start with 1 user and add one per second.
Constant Throughput Timer
Constant Throughput Timer can be used to set exact load in "Requests per minute".
Synchronizing Timer
Synchronizing Timer pauses test threads until threshold specified is reached. Once there are enough threads in pool JMeter releases them all at the same moment providing "spike" simultaneous load.
You can also use i.e. Ultimate Thread Group available via JMeter Plugins which provides easy and quick way of defining load scenario like:
Start with N users
Start up for S seconds
Hold the load for L seconds
Shut down test threads in T seconds
Hope this helps.
first of all both Load test & Stress test can help you determine the capacity of the system.
In order to perform load test, use the "Thread Group" available in Jmeter.
http://jmeter.apache.org/usermanual/test_plan.html
while doing a load test you will have to increase the user load gradually after 1 iteration has been executed completely e.g. you want to execute load test for 100, 200, 300, .... ,1000
so first iteration you have to keep "no. of threads" as 100, run the test save the results and then change the value in "no. of threads" to 200 & so on.
In order to perform stress test, use "jp#gc Stepping Thread Group"
http://testingfreak.com/tools/jmeter/stepping-thread-group/
hope this will help.
Related
I have a requirement to create simple Burst test in Jmeter:
10 requests-> 20 requests -> 30 requests
On single worker mode.
Throughput 20ms
Anticipated response time : <=200ms
How can we achieve this with Jmeter without using parallel threads?
I am looking for a simple solution.
Thanks a lot
Add plugin
Ultimate Thread Group to JMeter
Add Ultimate Thread Group component with settings of 3 rows
Set Start Threads Count 10,20 and 30
Use different start times so requests batch will be executed in different times
"Ultimate" means there will be no need in further Thread Group plugins. The features that everyone needed in JMeter and they finally available:
infinite number of schedule record
separate ramp-up time, shutdown time, flight time for each schedule record
and, of course, trustworthy load preview graph
Consider using Throughput Shaping Timer and Concurrency Thread Group combination which provides flexible way of defining load patterns:
They can be connected together using Feedback Function so JMeter will be able to kick off more threads in order to reach the desired throughput (number of requests per second) if current amount is not enough.
Both can be installed using JMeter Plugins Manager:
i am running a simple test with 10 users for 5 mins. my test has a single thread and different transactions within it. By the end of the test, there is a different number of samples for each transaction. Is there a way or a setting so that we don't start any new thread when the test is finishing, i tried ultimate thread group plugin with ramp down , hoping to see same samples for all requests but it didn't happen. Not sure if that is even possible.
Each JMeter thread (virtual user) executes Samplers upside down (or according to the Logic Controllers)
When you're defining test duration it might be the case that some virtual users are somewhere in the "middle" of the Samplers and they stop when they receive shutdown signal.
It means that the very first sampler will be executed with 100% of users and for further samplers the chance of getting executed becomes lower and lower.
The only way to have the same number of Sample Results for all Samplers is using normal JMeter Thread Group and providing fixed amount of loops.
Given above setup you will have strictly 80 executions of each and every Sampler in the Test Plan
More information: Getting Started with JMeter - A Basic Tutorial
While understanding concept of Concurrent thread and ultimate thread group, i am confused to understand result of summary/aggregate report while running concurrent thread or ultimate thread group .For example if i have 200 user and ramp up time 60 sec then i didn't see all sampler request as 200 sample after completing execution successfully but only few sampler request have 200 sample. when i use normal thread group then i always got thread count same for each sampler request after completing execution .
for realistic load testing with more user , could you please suggest me which thread group should prefer.
Could you please provide valuable guidance with some valuable link/book and also share me standard performance bench mark criteria or key parameter detail while doing load testing.(if any bench load parameter value does not meet standard then we can say that there is a performance issue)
Thanks for giving valuable time in advance.
Thanks
amit
This is due to the fact that:
Your application response time is too high
Your test duration is too low
For example I can see response times > 80 seconds:
it means that if a single virtual user has cumulative response time for 2 samplers > 160 seconds and the test duration is 120 seconds it will not be able to execute all the requests. Just increase your test duration to be i.e. 10 minutes and you should see more virtual users capable of executing all the Samplers you defined in the test plan.
Also given first user is capable of executing all the requests successfully and in time it looks like that your application gets overloaded hence cannot respond fast enough when the number of concurrent users reaches some "critical threshold", you can add listeners like Active Threads Over Time and Response Times vs Threads, this way you will be able to correlate increasing load with the increasing response time.
If also makes sense to collect:
Baseline health metrics of your application (CPU, RAM, Network, Disk usage, etc.), it can be done using JMeter PerfMon Plugin.
Lower level details like slowest methods, largest objects, heaviest database queries, etc. This form of information can be obtained using profiling tools specific to your application programming language(s).
I would like to make Recovery testing to server, I can simulate connection pool full with high load and thus failed in timeout to get connection.
I need to start my test with high load, reach a failure and decrease load gradually,
JMeter can't change it dynamically so I search for plugins and Concurrency Thread Group is doing the opposite,
Increase it gradually, is there a way to make it decrease the value?
Is my only option is to start a new execution with decreased load?
Recovery testing is done in order to check how fast and better the application can recover after it has gone through any type of crash or hardware failure etc.
It can be done using vanilla JMeter without any plugins, JMeter acts as follows:
All threads defined in the Thread Group are started within specified ramp-up period (here you can gradually increase the load)
All threads start executing samplers upside down (or according to the Logic Controllers)
When thread doesn't have any samplers to execute and/or loops to iterate - it's being shut down.
So given you gradually start your requests and thread group is not configured to run forever - the ramp-down should be pretty much the same as ramp-up. You can "help" JMeter a little bit using Gaussian Random Timer, check out How to Ramp Down in JMeter guide for more details.
I found a jmeter plugin jp#gc - Ultimate Thread Group which I can start with high load by adding first row with high thread count and then decrease thread count by adding second (or more) row .
I am quite new to jmeter and try to do a performance test of my application. I want to generate 100 request per second scenario however my server takes 3-4 secs to respond to every request. I am running my test for 1 mins which means number of requests fired should be 60k within the time span. However jmeter actually waits for the response before it sends next request. Which is not what I am looking for.
How can I make sure that jmeter sends a new requests every second with 100 req/sec without waiting for the response so that the number of requests fired per min is 60k.
I am trying to use constant throughput timer with 60k as request per min, however that is not helping. Here is my test screenshot.
EDIT
I have done like this
And Throughput shaping timer being as
So ideally I should get number of samples as 3000?, still not getting that.
Make sure you provide enough threads (virtual users) under Thread Group, "vanilla" JMeter won't kick off any extra threads if actual throughput is less than target one you specify in the Constant Throughput Timer.
Another solution would be using Concurrency Thread Group along with the Throughput Shaping Timer. They can be tied together via feedback loop so if you use these test elements JMeter will start more threads if the current amount won't be enough to reach the desired requests per second rate.
You can install both using JMeter Plugins Manager
My suggestion is to consider using the Arrivals Thread Group. This TG will allow you to configure the desire average throughput (ATP); the TG will instantiate the required threads needed to achieve the ATP goal.