Cannot open jatos via ECS server

Comments

• kri

  July 2020

  Hi Chi,

  If you use Apache in front of JATOS you don't have to specify IP and port in JATOS' config. You can leave the default values which are 127.0.0.1 and 9000. Setting up your public IP and port happens in Apache's config. Then Apache will forward all requests to JATOS. There are two lines in your Apache config that do this:

    ProxyPass / http://localhost:9000/
    ProxyPassReverse / http://localhost:9000/
  

  Another thought: you seem to have a public IP and a 'private' IP from Alibaba. I'm not sure which one goes in your Apache conf. Maybe try with both.

  Best,

  Kristian
• chizhang

  July 2020

  Hi Kristian,

  Thanks for the reply!

  The only place I could find ProxyPass and ProxyPassReverse is in the example.com.conf that I created and added to Apache following the tutorial. I tried to change the IP (both public and private) and the port but I still could not open the login page. And when I started loader.sh, the system still told me to use 127.0.0.1:9000. Maybe there are some mistakes that I am not aware of. I attached the screenshot of example.com.conf (in this version I used the pulic IP 39.102.52.116) and the information after I started loader.sh.

  Thank you!

  

  

  
  
• kri

  July 2020

  It's correct that JATOS tells you after you started it with loader.sh that it's IP and port are 127.0.0.1:9000. JATOS is not aware of Apache and the proxying of the network traffic.

  Looking at your Apache configuration the problem is in ProxyPass and ProxyPass. Both have to stay unchanged and point to localhost:9000

    ProxyPass / http://localhost:9000/
    ProxyPassReverse / http://localhost:9000/
  

  Best,

  Kristian
• chizhang

  July 2020

  Hi Kristian,

  Thank you so much for the reply! I changed the ProxyPass to localhost:9000 and tried to open jatos with both the private IP and pulic IP, but I still could not open the page. It is very strange.

  Best regards,

  Chi
• kri

  July 2020

  Hi Chi,

  Indeed this is strange. Can you do me the favor and run wget in your server's terminal on JATOS

  wget http://localhost:9000/jatos
  

  and on Apache

  wget http://39.102.52.116:80/jatos
  

  ?

  This way we can find out which part does not work. In the response should be HTTP request sent, awaiting response... 200 OK if everything worked fine or something with a 404 Not Found if not.

  I suspect that there is still something wrong in your Apache config.

  Best,

  Kristian
• chizhang

  July 2020

  Hi Kristian,

  Thank you for your patience! I tried to run the wget codes. Here are what we got:

  wget on JATOS

  

  wget on Apache

  

  Indeed both were failed. So something might go wrong with my Apache settings. Is there some way that I can diagnose where the problem is? Thanks!

  Best,

  Chi
• kri

  July 2020

  Actually both failed and if JATOS doesn't work properly Apache cannot proxy the requests to JATOS. So first you have to fix JATOS.

  • Could you please post/attach your JATOS log files here? They are in your JATOS folder in a folder named logs. There are two: application.log and loader.log.
  • Can you please post/attach your JATOS configuration in conf/production.conf here.
• chizhang

  July 2020 edited July 2020

  Hi Kristian,

  Please find the attached files application.log, loader.log, and production.conf (I cannt upload a .conf file so I changed the format to .txt)

  Thanks again for the help!

  Chi

  application.log

  loader.log

  production.txt

  
  
• chizhang

  August 2020

  Hi Krisitan,

  I still have not solved the problem with Apache. But the server worked when I disabled Apache. So I assume the problem lied on my configuration of the Apache. Thank you again for the help!

  Best regards,

  Chi
• kri

  August 2020 edited August 2020

  Hi Chi,

  Your production.conf looks okay.

  In the loader.log I can see this error:

  Oops, cannot start the server.
  akka.stream.impl.io.ConnectionSourceStage$$anon$2$$anon$1: Bind failed because of java.net.BindException: Address already in use
  Caused by: java.net.BindException: Address already in use
  

  This error means, that some other program is using the same address (IP + port) as you are trying to start JATOS on. Is it possible that you did start JATOS twice? Can you try to stop all JATOS instances and restart only the one with address 127.0.0.1:9000?

  Best,

  Kristian
• chizhang

  August 2020 edited August 2020

  Hi Kristian,

  Thank you for the response! I checked my Apache. It turned out that it might not be properly installed. I could not start the Apache service properly. When I tried to start the service it gave me:

   Job for apache2.service failed because the control process exited with error code.
  

  And by running code

  systemctl status apache2.service
  
  

  it gave me log like this:

  ● apache2.service - The Apache HTTP Server
     Loaded: loaded (/lib/systemd/system/apache2.service; enabled; vendor preset:
    Drop-In: /lib/systemd/system/apache2.service.d
             └─apache2-systemd.conf
     Active: failed (Result: exit-code) since Tue 2020-08-04 04:19:25 CST; 1min 43
    Process: 9574 ExecStop=/usr/sbin/apachectl stop (code=exited, status=1/FAILURE
    Process: 19884 ExecStart=/usr/sbin/apachectl start (code=exited, status=1/FAIL
   Main PID: 4076 (code=exited, status=0/SUCCESS)
  
  
  Aug 04 04:19:25 chizhang systemd[1]: Starting The Apache HTTP Server...
  Aug 04 04:19:25 chizhang apachectl[19884]: AH00526: Syntax error on line 5 of /e
  Aug 04 04:19:25 chizhang apachectl[19884]: Redirect to non-URL
  Aug 04 04:19:25 chizhang apachectl[19884]: Action 'start' failed.
  Aug 04 04:19:25 chizhang apachectl[19884]: The Apache error log may have more in
  Aug 04 04:19:25 chizhang systemd[1]: apache2.service: Control process exited, co
  Aug 04 04:19:25 chizhang systemd[1]: apache2.service: Failed with result 'exit-c
  Aug 04 04:19:25 chizhang systemd[1]: Failed to start The Apache HTTP Server.
  
  
  

  I don't know where the service went wrong. I could not start the instance with address 127.0.0.1:9000 via JATOS proxy. For now I took the simple solution by just stopping all the service of Apache. After all the Apache service stopped. I could use production.conf to start JATOS via my private IP and it worked.

  Best regards,

  Chi
• kri

  August 2020

  Hi Chi,

  The Apache setup is out of scope for this forum, but I can give you some short hints anyway:

  • Try the easier setup on DigitalOcean: http://www.jatos.org/JATOS-on-DigitalOcean.html
  • Have a look in Apache's log /var/log/apache/access.log
  • Try Nginx instead of Apache: http://www.jatos.org/JATOS-with-Nginx.html
  • Use experiments.jatos.org (it's free during COVID-19)

  Best,

  Kristian
• chizhang

  August 2020

  Dear Krisitan,

  Thanks a lot for the suggestion! I will try to use Nginx instrad of Apache if necessary.

  Best regards,

  Chi