Hello good,

We have set up a Limesurvey with about 4,000 active surveys.
We have noticed that the performance has dropped quite a bit. We even had to modify the "memory_limit" parameter of php so that some .php would load correctly.

What resources should the server have so that it goes smoothly with more surveys? We have a forecast of 5000 simultaneous.

Thank you very much and greetings!

If you are talking about "4000 active surveys" are you really talking about different surveys (e.g. different questionnaires) or are you talking about 4000 simultaneous accesses to fill out a survey?

This is quite a bit and will of course have a strain on servers. I think the most important thing is that there is enough space for the session files, which can be quite big and that the disk/ssd is quick to deliver them.

But I am not a server expert and also not an expert on high volume installations.

But why did you not answer the basic questions (e.g. your Limesurvey version, where it is hosted, etc)? These questions are not there for fun.

They might shed some light on solutions. I assume that you run either LS3 or LS5, in this case the requirements should be very similar, I guess.

scarpio wrote:

What resources should the server have so that it goes smoothly with more surveys? We have a forecast of 5000 simultaneous.
 

There is no rule of thumb for answering your question. There are too many things which can change the performance (webserver, PHP version, way PHP and webserver are connected, server resources etc,).  4000 active surveys are only demanding only more databasestorage than one active survey. But concurrent respondents visiting these surveys are causing load on your server.
So one survey visited by thousands of respondents at the same time are causing more trouble than one visitor to 4000 active surveys. The bottleneck might be one popular survey.
 

Hello good,

The version of LimeSurvey is 5.0.13.
The machine has 4 Intel(R) Xeon(R) Gold 6126 CPU @ 2.60GHz, 4GB of memory and 20GB of storage.

The surveys are different, 4000 active simultaneously and each one with different respondents. There can be anywhere from 30 respondents to 500.

Thank you very much and greetings!

Hello good,

The surveys are different, 4000 active simultaneously and each one with different respondents. There can be anywhere from 30 respondents to 500.

We have looked at different LimeSurvey with different surveys and we rule out that it is a bottleneck of a survey, since in all of them it begins to slow down with some 4000 surveys.

Thank you very much and greetings!