High performance Glassfish 4.1 processor

I have a problem with GlassFish 4.1 (Java 8 update 20, Windows Server 2008).

As soon as application usage increases, one of the cores goes to maximum load and remains the same even after all clients have disappeared. Restarting GlassFish helps.

It looks to me like this is an acceptor thread (currently only one in use). I tested with two acceptor strands, and as a result, two of the cores went full load.

Similar problem here: Glassfish 4 Grizzly Threads Heavy CPU usage .

Any ideas are appreciated.