JATOS server and static folder on Apache2

steffejr

Hello,

I am using JATOS with jspsych running on a server using Apache2. I used the configuration file as described on the JATOS website.

My problem is that I have a whole series of components that get executed/served. For each component many of the same files are downloaded. For instance, jspsych.js, jspsych.css, etc.

I am looking for ways to cache these files. I see since JATOS creates unique URLs each time, so that caching is not possible. So the idea is to create a static folder to put the jspsych code and then import it into my html components. We (actually my local IT genius) have been working with the apache2 CONF file and have had no luck getting this work. We have added things like the following to the conf file:

DocumentRoot /var/www/html

 Alias /static /var/www/html

My goal is to speed things up as much as possible. Can anyone provide some guidance, please?

Thank you,

Jason

kri

Hi Jason,

I see since JATOS creates unique URLs each time, so that caching is not possible.

That is correct. But JATOS additionally to the file serving does some authorization. Only participants currently running a study are allowed to access the files in the study assets folder. If you have some files there that not everyone should be able do access, e.g. trial data, this is what you want. On the other side if you have just 'normal' files, like images or videos, there is no reason to not put them somewhere else, e.g. in some folder where Apache can do the delivery faster.

We (actually my local IT genius) have been working with the apache2 CONF file and have had no luck getting this work.

I tried a bit to get this work but failed too. I'm not much of an Apache expert, I guess. It shouldn't be too difficult though, one part of the requests get delivered by Apache as static files and the other part get proxied to port localhost:9000 where JATOS lives. My config looks something like this, but somehow the static files do not get delivered.

<VirtualHost *:80>
  ServerName example.com
  ServerAlias www.example.com

  Alias /static/ /var/www/html/
  <Directory /var/www/html/>
    Options Indexes FollowSymLinks
    AllowOverride None
    Require all granted
  </Directory>

  ProxyPass /static/ !

  # JATOS uses WebSockets for its batch and group channels
  RewriteEngine On
  RewriteCond %{HTTP:Upgrade} =websocket [NC]
  RewriteRule /(.*)           ws://localhost:9000/$1 [P,L,UnsafeAllow3F]
  RewriteCond %{HTTP:Upgrade} !=websocket [NC]
  RewriteRule /(.*)           http://localhost:9000/$1 [P,L,UnsafeAllow3F]

  # Proxy everything to the JATOS running on localhost on port 9000
  ProxyPass / http://localhost:9000/
  ProxyPassReverse / http://localhost:9000/
</VirtualHost>

Please tell me when you figured it out. I'm curious!

Best,

Kristian