Inconsistent behaviour when loosing network connection

We have a very big problem with inconsistent behaviour of Vaadin when the network connection is lost.
We had many reports of “Communication errors”, we couldn’t reproduce in development.

So after some back and forth I decided to try to reproduce the error in a virtual machine. The server (apache tomcat) was started on the local development machine and the clients (IE11, Chrome 38, Firefox 33) in a vm.
The application was started in the browsers and some subapp with many input fields was started. Then the network connection was dropped.
Firefox just showed the spinning circle in the right top corner, but you could input text in the fields…
Chrome and IE immediately showed the red “Connection error Click here or press ESC to continue” error and the application was unusable.
When network connection was restored, you could press “Save” in Firefox, but in Chrome and IE you had to start over at the login and all input in the application is lost.

The question is, why is this behaviour so inconsistent. The only acceptable behaviour is that in Firefox.
Did we something wrong in our implementation?
We have a situation with spotty network connections at the customers site so what should we do?


I don’t think there’s currently a way to handle this nicely - a steady network connection is assumed. There’s an enhancement ticket about this at