3

I am looking for guidance/ideas on how to debug this problem.

Vaadin 8.1.5 including vaadin push.

During local development, I can open 50 tabs no problem. Windows 10, eclipse, tomcat 8.0.38 (http), jdk 1.8.0_131.

Production: AWS Ubuntu Server 14.04 LTS, Tomcat 8.5.16 (http) behind Apache 2.4 proxy (https), java 1.8.0_144.

As soon as I open a 6th browser tab (it's always the 6h) to the application, all tabs stop responding. No error happens, just the loading indication when I hit F5. As soon as I close any one tab, all other tabs become responsive again and reload.

I don't even know where to start looking. Any ideas/pointers highly appreciated.

I already investigated memory usage. There is enough free memory available (like 50 used of 500 MB).

Update: The problem only occurs with Chrome. I can open a dozen tabs to the same application with Firefox.

enter image description here

Reto Höhener
  • 5,419
  • 4
  • 39
  • 79
  • 1
    What happens when you open 6 browsers on different computers? – André Schild Dec 31 '17 at 09:11
  • 1
    I have a hunch it has nothing to do with vaadin. AWS may try to prevent denial-of-service attacks, or something. Maybe it's a setting somewhere. – Mordechai Jan 02 '18 at 17:39
  • 2
    My intuition tells me that you're using `@Push` which uses web sockets and Amazon doesn't allow more that 5 simultaneous open web sockets from the same ip address. Try removing push and see if you still have problems. – Mordechai Jan 02 '18 at 17:50
  • Thank you very much for your suggestions, which I will investigate. – Reto Höhener Jan 02 '18 at 21:21
  • @MouseEvent your comment brought me to this: https://stackoverflow.com/questions/32697909/how-to-solve-chromes-6-connection-limit-when-using-xhr-polling (looks like my problem) – Reto Höhener Jan 02 '18 at 21:31
  • And this: https://stackoverflow.com/questions/985431/max-parallel-http-connections-in-a-browser – Reto Höhener Jan 02 '18 at 21:35
  • 1
    Scanned that post, Maybe try playing with [`Transport`](https://vaadin.com/api/7.7.3/com/vaadin/shared/ui/ui/Transport.html) in `@Push(transport=...)` – Mordechai Jan 02 '18 at 21:39
  • Yes, I just started doing that, but it will take a while. I haven't chosen any of these settings consciously. Looks like there exist different limits based on browser, server, connection type, proxy and Vaadin push configuration... – Reto Höhener Jan 02 '18 at 21:44

0 Answers0