how can we find rendering time from using values such as Latency, Connect time, Elapsed Time, Idle Time available to us in jtl file generated at end of test?
Is the below approach correct?
Rendering Time = Elapsed Time - Connect Time - Latency
This way (excluding network transport metrics) you will be able to get server response time, however as per JMeter project main page
JMeter is not a browser, it works at protocol level. As far as web-services and remote services are concerned, JMeter looks like a browser (or rather, multiple browsers); however JMeter does not perform all the actions supported by browsers. In particular, JMeter does not execute the Javascript found in HTML pages. Nor does it render the HTML pages as a browser does (it's possible to view the response as HTML etc., but the timings are not included in any samples, and only one sample in one thread is ever displayed at a time).
So JMeter will not actually load DOM, execute scripts, and display the generated page, it just sends a request, receives "plain" response and measures time in-between.
If you need to measure page rendering page while your application is under the load I would recommend going for WebDriver Sampler which provides JMeter integration with Selenium browser automation framework. This way you will be able to measure real user experience and you will have a possibility to use Navigation Timing API to get some extra information regarding page loading events and their duration.
Related
For performance testing testing Jmeter UI - endpoint - response time deferring from developer tool loading time
Ex Jmeter - endpoint response time is 615 Ms where in developer tool shows (Load: 13.30 s) Finish: 18.98 s
Note : Jmeter capturing 35 backend call/ Developer tool capturing 104 backend call
why jmeter couldn't capture all developer tool backend calls?
why jmeter couldn't capture all developer tool backend calls? do we have any solution for this issue
As per JMeter project main page:
JMeter is not a browser, it works at protocol level. As far as web-services and remote services are concerned, JMeter looks like a browser (or rather, multiple browsers); however JMeter does not perform all the actions supported by browsers. In particular, JMeter does not execute the Javascript found in HTML pages. Nor does it render the HTML pages as a browser does (it's possible to view the response as HTML etc., but the timings are not included in any samples, and only one sample in one thread is ever displayed at a time).
So apart from configuring JMeter to behave like a real browser when it comes to handling embedded resources, cookies, think times and so on you need to pay attention to the nature of the requests which are being called when you open the page in the browser.
If the request is created by JavaScript, i.e. it's an AJAX call JMeter won't make the request automatically when you open the page. However you can record it using JMeter's HTTP(S) Test Script Recorder and run after the main request. The cumulative response time can be measured using Transaction Controller
Check the Retrieve All Embeded Resources in Advanced tab of the http sampler and see what is the difference.
Times will be always slightly different between dev tools and Jmeter or between JMeter and other performance tools like Gatling for example.
I am new to performance testing. I have a task on measuring the web application performance. I need to find out which modules/calls are causing deadlock, timeout and memory issues.
Q1. How can I use JMeter to find out deadlock, memory and timeout issues? If I do the following steps, it is the right way to trace those issues?
create a test plan in JMeter, which contains multiple Thread Group.
In each thread group, it contains multiple HTTP requests and 200 or
more users plus infinite loop.
Monitor JMeter results and SQL
profiler for deadlock.
Q2. JMeter is the right tool for tracking those issues? Or, should I use browser based performance testing tool such as LoadNinja, LoadView?
Thanks
Bonnie
Q1 JMeter per se doesn't provide any toolchain to detect deadlock and memory issues, the HTTP Request sampler (or even better HTTP Request Defaults) provides possibility to set the timeouts, if the value is blank - it will default to operating system timeout or web server timeout, whatever comes the first
If you conduct some form of stress test, i.e. start with 1 virtual user and gradually increase the load at some point you will see that response time starts growing and number of requests per second starts decreasing. So it's the point of maximum system performance and after that the performance will be degrading.
To monitor application under test memory you can use JMeter PerfMon Plugin, it will allow you to state whether the lack of RAM is the cause of the performance issue
With regards to deadlocks, it should result in HTTP Request sampler failure (or timeout), JMeter won't give you the underlying reason, but it will give you the timestamp and you should be able to check what happened with your application/database at that moment.
Q2 well-behaved JMeter test must produce the same network footprint as a real browser, if your test plan is good enough the system under test shouldn't be able to distinguish whether it's being hit by JMeter or by a real user using the real browser. JMeter will not give you client-side performance metrics like page rendering time or JavaScript execution time as:
JMeter is not a browser, it works at protocol level. As far as web-services and remote services are concerned, JMeter looks like a browser (or rather, multiple browsers); however JMeter does not perform all the actions supported by browsers. In particular, JMeter does not execute the Javascript found in HTML pages. Nor does it render the HTML pages as a browser does (it's possible to view the response as HTML etc., but the timings are not included in any samples, and only one sample in one thread is ever displayed at a time).
I have been using Jmeter for performance testing my web application. I have recorded the jmeter script by excluding js,css and other static content files.
While running the script, Jmeter doesnt execute javascript files so ajax XHR request are not sent. To overcome this i have recorded the script with js, css and other static content and it recorded all the Ajax xhr request too. But the performance results seems to be different from the browser loading time. Also i need to use cache during my performance testing.
Below is how my test plan will look like,
Included Retrieve all embedded resources in HTTP Request manager.
Concurrent pool size is 6
I have added HTTP cookie manager and Cache manager.
I have added a loop controller (This is for caching, jmeter will cache the files on first iteration and it will use the cached files
after that)
The problem i am facing is that the time taken for rest call are double the time shown in the browser console for single user. I have tried all other combinations but always i am getting higher time than the browser console.
I have tried to use the Selenium webdriver plugin to simulate the browser behavior but it doesnt seems to be using the cache. (https://www.blazemeter.com/blog/how-load-test-ajaxxhr-enabled-sites-jmeter)
Is there any other way to solve this problem? I want to take the metrics with cache so kindly suggest me any solution that must include cache. Or is there any other tool similar to jmeter that could solve this issue. My goal is to take web page load time with cache for 'n' number of users.
PS : I am even interested to write any scripts in jmeter but the scripts should not overload the performance of jmeter.
Thanks in advance.
You should not be recording calls to embedded resources (images, scripts, styles, fonts, etc.) as if you record them - they will be executed sequentially while real browsers do this in parallel. So remove recorded requests for the embedded resources and "tell" JMeter to download them (and do it in parallel) using HTTP Request Defaults
You should be recording AJAX requests, however real browsers execute them in parallel while JMeter runs them sequentially. In order to make JMeter's behavior closer to real browser you need to put these AJAX calls under the Parallel Controller
You can install the Parallel Controller extension using JMeter Plugins Manager
Jmeter and caching are unrelated - everything that happens after data went over the wire is out of scope by design. You should only ever simulate requests that you expect NOT to be cached. So this is the feasible part: drop all requests that you expect the browser to cache from the Jmeter script (or move them outside the loop). On the load time of XHR: the browser will most certainly use HTTP keepAlive. Result is that all requests except the very first skip the setup and teardown phase of TCP sockets and are much faster - esp. when the request itself is small and quick. You can simulate this in JMeter also by checking the KeepAlive option AND selecting http commons as implementation. You can read up on this in the docs here: http://jmeter.apache.org/usermanual/component_reference.html#HTTP_Request
I use JMeter for checking load testing.
I note a time with stopwatch when i check load time personally it was
8.5 seconds
when i run same case with JMeter it gave load time of 2 seconds
There is huge difference between them, How can i verify the actual time?
e.g : if one user taking 9 seconds to load the form while in JMeter it is given load time 2 seconds
Client time is a complex item, as you can see from the clip from the Chrome Developer tools, performance tab, above. There's lots going on at the client which does lead to a difference between the time you see with an HTTP protocol test tool, such as JMETER (and most of the other performance test tools on the planet) and the actual client render.
You can address this Delta in a number of ways:
Run a single GUI Virtual user. Name your timing records such as "Login" and "login_GUI." The delta between the two is your client weight. Make sure to run the GUI virtual user on a dedicated host to avoid resource contention
Run a test with all browsers. This was state of the art in 1995. Because of the resource cost and the skew imposed on trying to figure out the cost of the server response the entire industry shifted to protocol level virtual users. Some are trying to bring back this model as "state of the art." It is not
Ask a performance question earlier, also known as "shift left..." Every developer has these developer tools at their disposal, as does every functional tester. If you find that a client is slow for one user, be curious and use the developer tools to identify, "why?" If you are waiting to multi user performance testing to answer questions related to client weight, then you have waited too long and often will not have the time or resources to change the page architecture in meaningful ways to reduce the client page cost. This is where understanding earlier has tremendous advantages for making changes.
I picked the graphic above deliberately to illustrate the precise challenge you have. Notice, the loading of the components takes less than a tenth of a second. These are the requests that JMETER would be making. But the page takes almost five seconds to "render." Jmeter is not broken, it is working as designed. It is your understanding that needs to change on which tools can be used to pull particular stats for analysis.
You can't compare JMeter load time to browser as is, also because your browser will load JavaScript files and can call JavaScript functions on page load while JMeter doesn't execute JavaScript.
JMeter is not a browser, it works at protocol level. As far as
web-services and remote services are concerned, JMeter looks like a
browser (or rather, multiple browsers); however JMeter does not
perform all the actions supported by browsers. In particular, JMeter
does not execute the Javascript found in HTML pages. Nor does it
render the HTML pages as a browser does (it's possible to view the
response as HTML etc., but the timings are not included in any
samples, and only one sample in one thread is ever displayed at a
time).
Just a side note - you can use plugin to check exact load time in chrome.
Well-behaved JMeter test timing should be equal or similar to real user timing, if there is a 4x times difference - most probably your JMeter configuration is not correct.
Probably the most important. Make sure your HTTP Request samplers are configured to retrieve so called "embedded resources" (images, scripts, styles) which are referenced in the web page
If your application is using AJAX technology make sure you execute AJAX-driven requests as well and add their elapsed time to main sampler using i.e. Transaction Controller.
Make sure you mimic browser's:
Cookies via HTTP Cookie Manager
Headers via HTTP Header Manager
Cache via HTTP Cache Manager
Assuming all above you should be receiving similar to real user experience page load time. See How to make JMeter behave more like a real browser article for more detailed information on the above tips.
In addition to the answers provided by James and user7294900, please find these images to help you understand the reason behind the difference in time given by your stop watch and JMeter.
Below image gives the ideology behind how JMeter provides the time.
Below image gives the ideology behind how you have measured the time with
your stop watch.
Notice that there are additional actions performed by the browser when you are taking the time using your stop watch. This is the reason behind the huge difference in time between JMeter and your stop watch.
In addition to this, ensure that you are using the same test environmental conditions for both the tests (like same network conditions, same LG etc.)
Hope this helps!
How can we capture the end user response time in JMeter?
If there is any plug-ins available?
Can u please help me.
As per the main page of the Apache JMeter project
JMeter is not a browser, it works at protocol level. As far as web-services and remote services are concerned, JMeter looks like a browser (or rather, multiple browsers); however JMeter does not perform all the actions supported by browsers. In particular, JMeter does not execute the Javascript found in HTML pages. Nor does it render the HTML pages as a browser does (it's possible to view the response as HTML etc., but the timings are not included in any samples, and only one sample in one thread is ever displayed at a time)
Well-behaved JMeter test acts quite similarly to read users using real browsers given you properly handle embedded resources, cookies, headers, cache, AJAX calls, etc. See How To Make JMeter Behave More Like A Real Browser article for JMeter tuning recommendations.
I would also recommend using i.e. YSlow or WebDriver Sampler to measure real life user experience while the main load is being conducted using JMeter, this way you will be able to get more precise picture.