I am testing asp.net website using Jmeter. I have used below scenarios to load test. Scenario 1 give me correct result(What I expect and can be wrong) and Scenario 2 is not giving same result. But I have used same number of requests within same time. Can someone explain me why is this?
Scenario 1.
Scenario 2.
Ramp up time does not determine when any of your tests are going to complete. It only controls when your test is going to start.
Also, the number of threads any test can create concurrently is limited to the memory you've allocated to JMeter. Even though you've set the thread count to 60000, if you've hit the maximum memory you've allocated, the threads will either queue up or never generate (you can watch the JMeter logs for thread creating or errors).
I recommend tuning your JMeter instance so you have some stability to your tests, here's a good guide. LINK
No of requests you have sent might be same. But the concurrent user load on the server is completely different.
I had clarified similar question few weeks ago. You can check the answer here.
Check Here
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I am running jmeter tests with 100 to 1k users successfully,
But I suspect if response time is higher than expected.
My test plan include: get login and post login, get test page , post test page, get search page, post search page....
in total 5 get and 5 post forms.
For same number of users if I reduce number of pages the overall response time decreases
so should I run test for pages separately?
Should I reduce number of users for realistic numbers (5 pages*20 users=100 concurrent users)--for performance test?
Or should I be using distributed system?
What is the best practice?
Current Setup: i5, 8GB Ram, One windows machine with Jmeter 3.1
You load testing should be realistic, otherwise it does not make sense. You need to simulate anticipated users behaviour as closely as possible, only this way you will get the real life picture.
So you need to implement your test scenario to match the way, your site will be used in the real world. If it is alive already you can use Access Log Sampler to replay the traffic. If it is not, you can think about "user groups", like:
50% of not authenticated users will be browsing the site
20% of authenticated users will be browsing the site
5% of users will be in login process
3% of users will search for something
etc.
You can use different Thread Groups to represent different groups of users and Throughput Controller to control the frequency of samplers execution inside the Thread Group. See Running JMeter Samplers with Defined Percentage Probability article for more information on how to distribute the load in a realistic way.
There are N number of factors that will affect the overall response times. number of users / pages etc are also few of them. Do you have any specific requirement for performance test? If you are not sure of non functional requirements, then I think all your questions will be clarified in these posts -
http://www.testautomationguru.com/jmeter-performance-testing-application-of-littles-law-to-workload-models/
http://www.testautomationguru.com/jmeter-tips-tricks-for-beginners/
I think you could be running into jmeter issues. What is the JVM heap and GC algorithm that you are using? How are you measuring the performance of each page? If you are using "Transaction Controller" to measure the performance, any slowness in jmeter will affect your transaction controller values.
Have you correlated with the application logs to really understand that the application is indeed slowing down when you decrease the # of pages? If your application response time is constant, I think jmeter is the culprit here. Move all your measurements to the sampler level instead of transaction controllers and update the results
I have recorded a script against the application that I want to test. Now, I am having a hard time arriving at the decision that what is that number that the application will run without any issue and to find out the max number of users. Here is what I have done-
I have run the Jmeter script for 10, 50, 100, 150 users
Until 50 users, it runs like a charm. After about 80 users the throughput starts to come down and some samples do not show up in Aggregate Report.
I see heap memory problems in my console for about 150 users over period of time. Is it the application problem or my machine problem?
Do you have an article where I could read about how to come to a conclusion about THE number?
UPDATE- after increasing the heap size, it is running smoothly for 100 users. I am even more confused now
Thank you
The problem can be anywhere!
Server Performance Metrics collector:
First you need an agent running in the application server to monitor the server performance while you are running the test.
This link will give you an idea about the set up.
JMeter Best Practices:
I think that you are running your test in GUI mode with listeners. Most likely the problem is with your machine/your test. Ensure that you follow this.
Samples not showing in aggregate Report:
You already asked a question on this in SO. Do not select 'Successes' in the Log/display only section of the listener while writing the results in the jtl. It will not write the failed requests details. You might need all the results. Once the jtl is created, you can always filter 'Success' only results as and when you want.
I had used JMeter for load testing but was stuck at a point where had to execute parallel requests which does not seem possible with it.(if possible kindly explain)
So is there any open source tool which could help. Have to increase load upto at least 1000VU
Depending you your hardware you may need to consider remote (distributed) testing where one master host orchestrates multiple JMeter slaves to create immense load.
In regards to "concurrency" JMeter offers 2 test elements to control load pattern.
Synchronizing Timer - for firing X requests at the same moment of time
Constant Throughput Timer - to set exact load like X requests per second
which does not seem possible with it.(if possible kindly explain)
Increase the number of threads(users), that would be the number of simultaneous requests. The home page shows the exact example:
http://jmeter.apache.org/usermanual/build-web-test-plan.html
Hope this helps.
Feel free to try Yandex.Tank - https://github.com/yandex-load/yandex-tank. It can make to 80k parallel requests per second.
As Mr. Dmitri said, You can consider the distributed testing using jmeter.
Also consider the following points,
1.Use 64 bit JVM and increse the heap memory.
2.Run load testing in non gui mode and remove all listeners (you can add it after testing to display results)
3.Use latest version of Jmeter(2.11), because of optimal resource utilization (CPU,Memory). OR
Use Gatling load testing tool(http://gatling-tool.org/). You can find an comparative study of gatling Vs Jmeter
If suppose I will run load testing with 5000 threads or may be more ,
Will the main server under test crash at a certain level.
As EJP said, it is JMeter purpose to find the limit of tested application and how it will react under performance.
So yes it is perfectly possible.
You should read JMeter Manual.
If you are doing any kind of performance tests (load, stress, soak etc) you will want to know at what point your application server falls over i.e. its breaking point.
Once you've found out what your upper limit is, start dialing back the number of threads until you find your application's "sweet spot" for example CPU usage <80% & >70%
I want to load test a URL by hitting it few hundred times at same millisecond . I tried JMeter but I could hit 2 request at same millisecond. This seems to be problem that my machine cant create threads fast enough . Is there any solution to the issue ?
In JMeter you can use synchronizing timer setting it to 100, this way all threads will wait until there are 100 available and hit the server:
http://jmeter.apache.org/usermanual/component_reference.html#Synchronizing_Timer
Another solution is to increase the number of Threads so that you hit this throughput.
In next coming version (2.8) of JMeter you will be able to create threads on demand (created once needed).
Anyway hitting few hundred times at same millisecond is a high load so you will have to tune JMeter correctly.
Regards
Philippe
JMeter uses blocking HTTP client, in order to hit the server at the exact same time with 100 reqeusts you need 100 threads in JMeter. Even providing that, you still don't have 100 cores to actually run such code at the same time. Even if you had 100 cores, it takes some time to start a thread, so you would have to start them in advance and synchronize on some sort of barrier. And that is not supported in JMeter.
Why do you really want to run your server "at same millisecond"? An ordinary load test just calls the server with as many connections as possible, but not necessarily at the same time. Moreover, sometimes you are even adding random sleep between requests to simulate so-called think time.
As per Philippe's answer, JMeter does in fact support synchronous requests. But maybe for what you want something like Apache Bench using -c100 (or tune it to whatever works) is a better option? It's pretty basic stuff but then the overhead is a lot smaller which might help in this situation.
But I would also steal from Tomasz's answer and echo his concern that perhaps this is not really the best way to approach load testing. If you're trying to replicate real life traffic then do you really need such a high level of concurrency?
You need to use Jmeter-server and a host of client machines for load generation. Your single machine is not enough to generate the load itself.