Web servers#

PsyNet experiments currently support three main modes of deployment:

  • SSH to a custom server

  • Heroku

  • Local computer

SSH to a custom server#

This is the preferred option in most cases. The experimenter acquires some kind of Linux server to which they have SSH access, perhaps by purchasing a physical server that can be connected to the internet, or by acquiring a cloud server via a service such as Digital Ocean or Amazon Web Services. It’s recommended to find a server with at least 16 GB of RAM. There is then a built-in Dallinger command that connects to this server and makes it ready for hosting experiments: dallinger docker-ssh servers add.


An alternative approach is to deploy experiments using Heroku. Heroku is a cloud computing services provider that helps to orchestrate deployments of web apps. The advantage of using Heroku is that it performs the provisioning for you, i.e. spinning up web-servers when you launch the experiment and taking them down once you’ve finished. However, it comes with a big pricing disadvantage: running a Heroku experiment for a month could cost hundreds or even thousands of dollars, depending on the size of server provisioned. In contrast, the custom server approach should only cost tens of dollars.

Local computer#

If you are collecting data in person it is also possible to run experiments on your local machine, e.g. a laptop you bring to participants. We have not tested this workflow so much and so would generally recommend the online server approach for now, though. Watch this space!