jmeter slow response times

Question

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?

Answer 1

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.

Answer 2

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.