Dead connections

Hello all,

I find every day multiple times the following message:

WARN | https-jsse-nio-18443-exec-5 | org.atmosphere.cpr.DefaultBroadcaster | Duplicate resource 1285b512-0ab0-482a-8ad5-53be78a0fb82. Could be caused by a dead connection not detected by your server. Replacing the old one with the fresh one

It seems that there is a way to fix it. But unfortunately I do not know how:

Does anyone have an idea?

Best Regards,

At the end of the page you linked, there are two pieces of advice. In both cases you need to modify your proxy configuration. How these are done in detail depends which proxy you are using. You can find details by reading the documentation of you proxy (usually long read) or by googling stackoverflow and serverfault Q&A on the topic (e.g. Apache here​)

  1. If you are in control of the proxy, configure it not to timeout/kill push connections (connections to the /PUSH url)
  2. If you know what the proxy timeout is, configure a slightly shorter timeout for push in the Vaadin application so that the server terminates the idle connection and is aware of the termination before the proxy can kill the connection. Use the “pushLongPollingSuspendTimeout” servlet parameter for this (defined in milliseconds) (Vaadin 7.6+)


Thanks for the answer! Unfortunately I do not know what is required to configure it correct. I have a ebedded tomcat server (spring boot). I only set the folloing annotation on top of my UI: @Push(value = PushMode.AUTOMATIC, transport = Transport.LONG_POLLING)

Do I have control of the proxy (I think so ;-))? How can I find out the timeout? How can I configure to do not jill push connections?

Thanks in advance,