Okay, I will have a difficult time describing my problem. Our app seems to be getting in a deadlock situation  after about a day of operation. The only thing that changed was an upgrade to Wildfly 30 from Wildfly 26. (Wildfly 31 has the same issue). See the attached thread dump for details and look for thread 'default task-638'

It seems that the ServletOutputStreamImpl performs a blocking flush which stays in a loop. There is no more data to flush, but there is a loop in Channels.flushBlocking that keeps trying to flush, never stopping.

Should not the flush have a timeout? An eternal blocking flush does not sound as a good idea...