there was never jmx attribute connectionCount on xnio workers...
this are all attributes that are available there https://github.com/xnio/xnio/blob/3.3/api/src/main/java/org/xnio/management/XnioWorkerMXBean.java
thank you for looking into this.
When looking through the GitHub it does seem to be in this Bean here:
So youre right, its not actually the worker, but the server of a worker. (At least thats the structure i do see within JConsole)
But still, this value does not change for me in Wildfly 10, while this was still working on Wildfly 8.