hello dear OpenSuse-Experts hello and good day,

the issue and topic of today: running stresstest to check how healthy the server is - and to find out why a script sometimes stopps working:

note: the server runs on OpenSuse

Operating system	SuSE Linux 12.3
Webmin version	1.910 	Authentic theme version	19.33 
Time on system	Wednesday, November 27, 2019 6:59 PM	Kernel and CPU	Linux 4.4.148-ps on x86_64

in the past few weeks i have had some issues on a server - with Wordpress and Limesurvey. I also have openend a thread here. Now the site is up again and runs well. The limesurvey-page often has thrown a page like ERR_EMPTY_RESPONSE Error (both on FireFox and on Chrome)

Since 24 h. the behaviour is better - the site is up again. see path: http://www.f-s-j.de/limesurvey/index.php/admin/index
limesurvey :: https://www.limesurvey.org/about-limesurvey/ version 3.20.02

it is installed in (between) a wordpress :: in other words: the limesurvey was installed under a folder inside my wordpress installation.
Some limesurvey-experts say that i will get all kind of issues over the time. And that it has to do with the installation-structure:

- MyDomain.TLD/limesurvey/ (LimeSurvey)
- MyDomain.TLD/ (Wordpress)

hypothesis: LimeSurvey and Wordpress tell the server to rewrite URLs for the browser. In my setup Wordpress just tries to overrule certain settings of LimeSurvey. The Limesurvey-folks recommend that i would need to check every change and update manually the htaccess file (since i am running apache).

final recommendation: To minimize work and trouble, i should install wordpress and limesurvey side by side.
we then need to redirect from MyDomain.TLD/ -> MyDomain.TLD/wordpress/, but then (after this step) i have clean folders and don't cause delays and loops when it comes to URL accessing. This safe way of installation side by side includes a special procedure: to use /w/ for wordpress and /s/ for limesurvey will keep the URL short.

Again: the error way: ERR_EMPTY_RESPONSE - after it worked very well for weeks

what can i do now!?

btw. the wordpress on the server still runs well

question: can i perfom a so called stress- or perfomance-Test to see how healthy the server is!?
in other words: is there a Performance-, Last- und Stress-Test for a Webserver out there.

note: some data:
PHP Version 5.6.39
eg. wordpress-basic-installation
sometimes i get the error: ERR_EMPTY_RESPONSE Error

look forward to hear from you