Hello dear experts hello and good day,
the topic of today: ERR_EMPTY_RESPONSE :: possible root-causes for this error.
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
sometimes i get the error: ERR_EMPTY_RESPONSE Error - but at the moment all goes well... - with the stress-test i wanted to check out the system - and want to try to figure out when the server or the script quits the job ... and gives back the ERR_EMPTY_RESPONSE
update - update : well i also have discussed the issue with the limesurvey-user here: https://www.limesurvey.org/forum/installation-a-update-issues/119649-err_empty_response-after-it-worked-very-well-for-weeks/191580
after having mused bout the errors and the possible reasons - after having mused bout porting over the installation on subomains or a side to side installation i suddenly saw that the site is coming back...
note : i guess that the errors ERR_EMPTY_RESPONSE - is rooted in a very very weak server - just that easy - is this possible - is this thinkable!?
Holch - one user of the limesurvey - he has got the very same installation - structure as i have. the user holch: : in this thread you answer very interestingly : [quote] I run Limesurvey and Wordpress in a very similar setting (Wordpress in root and LS in subfolder) and I don't have the same problems. So while I wouldn't want to exclude this as the source of issues completely, I would probably focus on other aspects first, as it works fine with me for quite some time now. Of course, as Jelo says, any update in one of the two applications could start causing problems. [/quote]
Note: at the moment it goes very well - in other words i have no issues at the moment: Holch - is it thinkable that this error is rooted in a very slow server!? I have to admit that this seerver is very very old and will be replaced very soon (in a few weeks)
The error "ERR_EMPTY_RESPONSE" where is this error rooted :: is a ChromeBrowser error message, which tells us, that nothing was sent from the server to the browser. The empty or at least unusable answer from the server to the browser can be caused by many things. The delay can be caused by an overloaded shared webserver. It can be cause be a htaccess redirection instructions gone wild (e.g. installing a web application with own htaccess directions into another webapplication folder).
what do you guess - what do you say bout the error "ERR_EMPTY_RESPONSE"?
is up again. see path: http://www.f-s-j.de/limesurvey/index.php/admin/index
look forward to hear from you