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Your LimeSurvey version: url=https://community.limesurvey.org/]LimeSurvey Community Edition[/url] - [url=https://imrsite/limesurvey/index.php?r=surveyAdministration/listsurveys#modalSystemInformation]Version 5.1.10+210913[/url
Own server or LimeSurvey hosting: Own Server
Survey theme/template: fruity
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I had a recente issue. While sending invitations to an online survey, my helper forgot to spread the invitations and we had a lot of request connections to our limesurvey instalation.
This led to a DOS, and the websurver was unresponsive for a time.
After the web server started to respond again I observed a strange behaviour from limesurvey.
Whenever I tried a operation a litle bit "heavier", like, copy a survey, tried to see the logic of the survey, activating an survey, verifying the data integrity of the DB, etc, i got an error 500. The respondentes of the survey also started getting the same error.
After further testing i found out the limesurvey was getting an out of memory error, so i changed the max_memory setting in PHP from 256M to 512M.
After this change most of the 500 error went away, but i still can't check the DB integrity and sometimes while copying the survey I get the error (even tough the survey is copied). I also get a lot of complaints from respondentes due to the slowness of the survey.

Its not very normal limesurvey is using more than 512MB in a script… How can i check and correct what is wrong in my limesurvey instalation?

Thanks very much for any help.

Luis Azevedo
 

On this issue continuation, I have created a new server and installed there the most recent (at the time) limesurvey version.
The new server was completly new and clean. Every survey thus created there or imported run like a charm with no issues.
That is untill I needed to create a new version of the survey that originated the error in the previous server (or I first noticed the error).
When I tried to import the survey in the new server, I got exactly the same error...
When I remembered to check the lss file I was surprised to see it's size was almost 25MB. I went to check further and saw that the earliest verson of the survey was 8,7MB (4 versions before). Usually they are around 200kb to 600kb.
Checking further in the .lss file I saw that the <defaultvalues> area was ocupying almost 1 million lines in the file. this survey has no "default value" in any question, and this is something I rarelly use in other surveys (at most 1 question with this setting per survey).
In the DB the table has more than 300 000 lines for only 74 diferent qid.
I got the following:
Rows qid
19714 157170
19714 108308
19714 161471
16384 161472
16384 157171
16384 161494
16384 157193
16384 161507
16384 106421
16384 108309
16384 157206
16384 108331
16384 108344
16384 155158
8192 106422
8192 106444
8192 106457
8192 102198
4096 102199
4096 102221
4096 102234
2048 161521
2048 157220
2048 108358
1024 106471
There seems to exist a bug that will multiply in this table the lines, each time I copy a new version from the previous. all the "extra lines" have no information in them nor in the connected table "defaultvalue_l10ns" having only 0 in them.
I will remove the extra lines so I can work but there should be a verification of why this is happening, and preventing this multiplying lines.

Best Regards,

Luis Azevedo

Please file a bug report.

- bugs.limesurvey.org