Unexplainable WebSocket error

[glassfishrobot]

The server works perfectly fine, until at a random moment, it starts throwing hundreds of these per second:

Aug 09, 2016 10:54:08 AM org.glassfish.tyrus.container.grizzly.client.GrizzlyWriter$WriterCondition$1 onError WARNING: Connection closed java.io.IOException: Connection closed at org.glassfish.grizzly.asyncqueue.TaskQueue.onClose(TaskQueue.java:331) at org.glassfish.grizzly.nio.AbstractNIOAsyncQueueWriter.onClose(AbstractNIOAsyncQueueWriter.java:501) at org.glassfish.grizzly.nio.transport.TCPNIOTransport.closeConnection(TCPNIOTransport.java:402) at org.glassfish.grizzly.nio.NIOConnection.doClose(NIOConnection.java:647) at org.glassfish.grizzly.nio.NIOConnection$6.run(NIOConnection.java:613) at org.glassfish.grizzly.nio.DefaultSelectorHandler$RunnableTask.run(DefaultSelectorHandler.java:495) at org.glassfish.grizzly.nio.DefaultSelectorHandler.processPendingTaskQueue(DefaultSelectorHandler.java:301) at org.glassfish.grizzly.nio.DefaultSelectorHandler.processPendingTasks(DefaultSelectorHandler.java:290) at org.glassfish.grizzly.nio.DefaultSelectorHandler.preSelect(DefaultSelectorHandler.java:101) at org.glassfish.grizzly.nio.SelectorRunner.doSelect(SelectorRunner.java:335) at org.glassfish.grizzly.nio.SelectorRunner.run(SelectorRunner.java:279) at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591) at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571) at java.lang.Thread.run(Thread.java:745) Caused by: java.io.EOFException at org.glassfish.grizzly.nio.transport.TCPNIOTransport.read(TCPNIOTransport.java:597) at org.glassfish.grizzly.nio.transport.TCPNIOTransportFilter.handleRead(TCPNIOTransportFilter.java:75) at org.glassfish.grizzly.filterchain.TransportFilter.handleRead(TransportFilter.java:173) at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119) at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:284) at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:201) at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:133) at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:112) at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77) at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:526) at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56) at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137) ... 3 more

The seconds previous were just normal:

Environment

RAM 8GB Debian 7.5

Affected Versions

[1.12, 1.13]