System Requirements

For the installation of SoSci Survey a working webserver with suppoert on PHP and database. The installation requires the following software:

Webserver (Apache, nginx or for Windows Server IIS) or Webspace with PHP/MySQL (s. below)
PHP from Version 8.0 (PHP Supported Versions)
MariaDb or MySQL-Database from Version 5.7 (Supported Platforms: MySQL Database )

Even though SoSci Survey can handle outdated PHP versions, we strongly recommend using the latest program versions for each of the three components. Use on a webserver only software that gets security updates.

The following configuration has proven successful:

A (separate) VM (virtuell maschine)
- A VM is usually cheaper and easier to maintain than a hardware server.
- A seperate server is usually more stable and saver than if other (web-)applications run on in (s. below)
Linux operation system on the base of Debian or Ubuntu
Use of the web server application nginx, because it requires significantly fewer resources with a large number of participants

The power required for stable operation is not quite easy to quantify. It depends not only heavily on how intensively the server is used (100 interviews a day or 100,000) – SoSci Survey is also relatively sensitive to how fast the disks are working. It depends not only heavily on how intensively the server is used (100 interviews a day or 100,000) – SoSci Survey is also relatively sensitive to how fast the disks are working. LSlow data storage is mainly found on (a) old servers and (b) new servers when the data is stored on classic hard disks and not on SSD storage. For a reasonably up-to-date survey server with average to high interview volume (up to about 20,000 interviews per day), we recommend the following configuration:

2 CPUs or vCPUs
4 GB RAM
50 GB of fast hard disk space, e.g. SSD (about 10 GB for the operating system, <1 GB for SoSci Survey, 5 GB for the database, 25 GB for media files) – significantly more if video is used in the survey projects.

Note: The most validd webspace offers “on the internet” are so called “shared hosting”. In this wa there are running hundred or thousands of internet offers on one webserver. This webspace is offered alredy from a price under 2 Euro per month. So that the offers on such a server do not get in each other's way, the functions are often restricted a little (e.g. PHP runs in the so-called safe mode). In return, with shared hosting you don't have to worry about the installation and setup of the web server. SoSci Survey can be used on a shared hosting offer but under this circumstance it may not all functions be available (e.g. time-controlled sending of serial mails).

For the optimal use the server should support the following functions:

Possibility of time-controlled execution of scripts (cronjobs)
Operation of PHP without restrictions (PHP not in safe mode)
Installation of PHP modules, if they are not pre-installed

The task of the web server is to provide content from the server on the Internet/intranet. To make this running the webserver and if necessary the firewall must be correctly configurated. Please make sure that the webserver is accessable via HTTP-/HTTPS protocoll.

Tip for Windows: Unless you are already running an IIS web server and want to set up a local server on Windows, the installation package xampp from Apache Friends saves a lot of work. It contains a. o. a completly configurated Apache webserver inclusive PHP and MySQL.