I'm trying to simulate a connection to a website. The goal of the simulation is to collect statistics on page loading time on browser side.
I configured JMeter Flagging the option Retrieve Embedded Resources in order to simulate the real time to load the whole page. The issue is that while from a real Browser i have a response time (let's assume for the page A the response time is 10 seconds) in JMeter I found i response time 20 times higher.
It seems JMeter takes a much longer time to gather embedded resources (e.g. js, images, ...)
Do you have any suggestion for this issue?
Kind Regards
Update 31/07
I discovered some resources are not completely downloaded. Using Firebug i see some components with 0 bytes downloaded that the browsere keep trying to download (but the user do not percieve since the page is loaded). Therefore i suspect JMeter keeps trying downloading it. Is there any chance to set a timeout to overcome this kind of situation?
Update_1 31/07
I figured out that the issue is related with nested iframes. setting httpsampler.max_frame_depth=0 i get the correct time. however i would like to understand the reason of this issue. Do I have to set other paramters?
Disable browser cache and re-run your test in browser.
Jmeter will not store cache, unless otherwise specified.
Hope this will help.
Add a HTTP Cache Manager to your test plan.
Real browsers retrieve images, scripts, styles, etc. but do it only once. In order to simulate browser behavior you need to configure JMeter appropriately.
See How to make JMeter behave more like a real browser guide for more test elements which can be used for this.
Related
When I check the page loading time for a page in chrome Dev tool under network tab the system has taken 6 seconds
When I check the page loading time for a page in chrome Dev tool under performance tab the system has taken 8 seconds
When I check using jmeter by using blaze meter recorded file its taking 12 seconds..
Note: I have one main jsp request and 5 sub request....
Number of User:1
Ramp-up period:1
Loop count:1
I'm assuming you have kept embedded resources (such as png, img, gif, js files) in the script. If so, jmeter executes them in a sequence which increases response time. Try using retrieve embedded resources check box in HTTP request defaults and check parallel downloads. By default it's value is 6.
Most probably this is due to HTTP Caching, there are so called "embedded resources": images, scripts, styles, fonts, sounds, etc, if you visit the page in the browser not the first time - the chance that the embedded resources are not downloaded each time is very high.
JMeter always establishes "clean" session, so if you want to compare it's response time with browser response time you should set up "clean" session in the browser as well, i.e. tick "Disable cache" box in the browser developer tools
Check out How to make JMeter behave more like a real browser guide for more hints on how to properly configure JMeter for producing the same network footprint as real browsers do.
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!
I am performing baseline performance test on a project. Average load time reported by jmeter is much higher than actual load time in browser(fresh- no cache and cookies).
What will be the issue?
I suggest to check the following:
Load generator overload. Re-run JMeter test with one user/thread and compare with Firefox. If the results will be comparable then the response time in JMeter may be excessive due to its overload. Try to address it by adding more load generators.
Inaccurate browser emulation. If even with one user the response time in the load test is higher, then it can be caused by inaccurate emulation of browser paralel connections. To troubleshoot it, compare waterfall diagrams. To get it from Firefox, use Firebug. Route JMeter traffic through Fiddler which displays the waterfall on the Timeline tab. If the waterfalls are different, you may have the following issue: a web browser downloads resources in parallel, while by default JMeter replays recorded traffic sequentially. To fix it, add these settings: Simulating browsers using JMeter.
Are you checking with browser during the load test ? or at another time ?
In the latter case, you would be comparing apples and oranges.
Are you using JMeter GUI mode ? if yes, it's a bad practice, GUI mode is for scripting, NON GUI mode for load testing:
http://www.ubik-ingenierie.com/blog/jmeter_performance_tuning_tips/
How much threads are you using ? and which version of Jmeter ?
For embedded resources testing, 3.0 is the most realistic and performing:
https://jmeter.apache.org/changes.html
Whenever you run performance tests instead of Average response times, always consider 90th percentile. In some cases avg. response time is skewed even if one request takes long to respond. So please check 90th Percentile.
If you are running the test with multiple users, try to hit the application from browser while load test is going on and check the response time on browser. This will tell you if your observation is correct.
The load generator may not be able to establish enough connections due to which you might see higher response time. Check load generator utilization in case if you doubt. In some cases load generator itself can't generate enough load.
Check your sever utilization when you run the performance test. This will give you an idea if the application is not able to handle the load or if it's the issue with load generator.
If you are running tests from UI mode, please try to run tests with non-UI mode. (Can you specify with how many users you are running these tests?)
Increase JMeter memory if you see issue with load generator and keep eye on load generator CPU usage too.
Check if load generator and browser from which you are hitting the application are on the same network and check network latency to check if there is network problem.
I have set up a test plan using Apache JMeter, but when testing a remote server I am seeing much slower times than it takes the browser to run the same test, it's on order of 5-10x slower. For example chrome takes about 300ms to load a simple static page with some embedded assets while jmeter reports 2000+ms for the same page from the same machine.
I've tried tweaking the thread count to make sure this is not the bottleneck as well as not too much load slowing down the server, but nothing seems to change these slow numbers.
What else can I look at to get more realistic response times out of this tool?
I figured this one out, the issue was that "Retrieve all embedded resources" was checked, which I want, but I was also not using the "concurrent pool size" option, so it was cycling through each of the ~10 embedded HTTP requests on the page serially and reporting slow overall load times. Checking this and adding a realistic browser concurrency number (Chrome uses 6 these days so that's what I went with: http://sgdev-blog.blogspot.com/2014/01/maximum-concurrent-connection-to-same.html)
give me numbers that are very close to real browser testing.
Make sure you add HTTP Cache Manager as browsers download embedded stuff like images, scripts, styles, etc. but do it only once, on subsequent requests aforementioned resources are being returned from browser's cache, no actual request is being made.
See How to make JMeter behave more like a real browser guide for other recommendations on how to make your JMeter test more realistic.