Has anyone had any experience with limeSurvey with a questionnaire with more than 100 thousand participants or answers?



I would like to know how the server's stress was.


Thank you!

Limesurvey can handle 100.000 respondents without a problem. The problem is not the pure number. Problems can arrise when:
- many concurrent responses happen (Solution: send invitations out in smaller packages)
- many complicated filters and expressions

There are a few posts here in the forum about high traffic surveys. From what I read in the forum, the main problem is that LS currently creates relatively big session files and they might fill up your memory. So you need to have a good session handling or a lot of memory.

But have search on this forum, there have been quite a few discussions about this. Of course you won't find an out of the box solution, because this all depends on so many factors, but you will get a good idea.

Thank you very much, I will send the questionnaire to more than 100 thousand participants.

Yes, I understood this. But you can reduce the number of concurrent responses (and only these will be a problem) by sending the emails not all at once, but over a period of time in different batches. If you send 100.000 emails at the same time, chances are high that you will have a huge load of concurrent responses at the same time. If you now send the emails in batches over a period of 1 week for example, you can reduce the load of concurrent responses considerably. I don't know who your target group is and how important this survey is for them. But generally the response rate is not much higher than 5-10%. Only if there is a very strong relationship between your organization and the respondents there is a chance of a higher response rate. So your aim needs to be to make sure that the number of concurrent responses (people that really are filling in the survey at the same time) is as low as possible. If this is given, you can run a survey with 100.000 even with a relatively low powered server environment. The higher the expected number of concurrent responses is, the more power your system needs.

So it depends a little on how much time you have to run this survey. When you know that, you can calculate the concurrent surveys that are to be expected.

Then maybe someone else with more experience with high load server environments and Limesurvey can help.