Server Documentation

Warning

Before making any changes to the experimental servers make sure you check out the experiment calendar so you don’t make changes during someone else’s experiment.

Note

All servers use CentOS, so you use ‘yum’ to install packages.

Note

Example files are hosted under the leeps@ucsc.edu Google Drive account

Experimental Servers

• econ-leeps-3.ucsc.edu - Runs oTree 3

• econ-leeps-4.ucsc.edu - Runs oTree 3

• econ-leeps-5.ucsc.edu - Runs oTree 5

ORSEE

This stands for Online Recruitment System for Economic Experiments.

This is the website that is used to schedule experiments and invite subjects.

ORSEE Documentation

ORSEE Admin Page

Main Website

leeps.ucsc.edu

Main Website Admin Page

Server Maintenance Contact Information

Name: Doug Niven

Email: dniven@ucsc.edu

This is the person that will grant us new servers and SSL certificates.

If Doug is no longer available, contact UCSC ITS directly.

Reverse Proxy Service

Note

You need to be the root user to edit the Nginx configuration. You can do this by running ‘sudo -su root’.

Nginx is used for all the experimental servers and the Main Website. I’m not sure about ORSEE.

Nginx is also being used for SSL.

SSL certificates found in /etc/ssl

Nginx config found in /etc/nginx/conf.d

Nginx Configuration Example

Experimental Server Specifics

Required services

• PostgreSQL

  • Make sure you pip3 install psycopg2-binary

  • PostgreSQL Installation Tutorial

• Redis

  • Redis Installation Tutorial

• Git

  • sudo yum install git

• Nginx

  • Nginx Installation Tutorial

• Python 3.7

  • Python 3.7 Installation Tutorial

• Python virtual environment

  • Python virtual environment Tutorial

• Tmux

  • sudo yum install tmux

  • Refer to this to understand tmux

Important Commands

Note

Tmux allows you to continuously run services even when logging out

• tmux - Creates new tmux session

• tmux a - Attaches to last tmux session

• Ctrl + B + D - Detaches from current tmux session

• Ctrl + B + % - Creates new tmux pane

• Ctrl + B + (Arrow Key) - Move between tmux panes

• Ctrl + B + [ - Allows you to scroll in a tmux window

Service Files

Note

Service files allow you to run processes in the background.

• Service file tutorial

Commands to know

• sudo systemctl start otree.service

• sudo systemctl restart otree.service

• sudo systemctl stop otree.service

If you would like to see the output of the service file run the command below:

Note

I like to perform the command below in Tmux to show the output is saved even when I logout of the server.

sudo journalctl -f -u otree.service

Example service file

Adding experiments

Warning

Before doing this, ensure that all the data from other experiments have been downloaded. Make sure your project only contains your app, not the entire oTree configuration.

Steps

• Git pull your project in the oTree folder and add it to settings.py

• Make sure you export the database URL before running the command below

  • export DATABASE_URL=postgres://postgres:password@localhost/django_db
    

  • You can find the specific DATABASE_URL inside one of the service files in /home/leeps

• Run ‘otree resetdb’ to add new database columns

• Run ‘otree collectstatic’ to cache static files

• If the experiment doesn’t show up, run ‘sudo systemctl restart otree.service’