[jetty-users] "java.io.IOException: Cannot append to finished buffer" in

[Rossen Stoyanchev <rstoyanchev@xxxxxxxxxxxxx>]

hi-

I have a simple unit test in which a Jetty WebSocketClient connects to a Jetty server and sends 100 messages in a loop that the server then echoes back. When all messages are received in the client, the test is complete. This runs okay most of the times except occasionally on our CI server there is a client-side failure after 40-50 messages that looks like this:

java.io.IOException: Cannot append to finished buffer

        at org.eclipse.jetty.websocket.common.message.SimpleTextMessage.appendFrame(SimpleTextMessage.java:47)

        at org.eclipse.jetty.websocket.common.events.AbstractEventDriver.appendMessage(AbstractEventDriver.java:60)

        at org.eclipse.jetty.websocket.common.events.JettyAnnotatedEventDriver.onTextFrame(JettyAnnotatedEventDriver.java:201)

        at org.eclipse.jetty.websocket.common.events.AbstractEventDriver.incomingFrame(AbstractEventDriver.java:160)

        at org.eclipse.jetty.websocket.common.WebSocketSession.incomingFrame(WebSocketSession.java:302)

        at org.eclipse.jetty.websocket.common.extensions.ExtensionStack.incomingFrame(ExtensionStack.java:215)

        at org.eclipse.jetty.websocket.common.Parser.notifyFrame(Parser.java:220)

        at org.eclipse.jetty.websocket.common.Parser.parse(Parser.java:258)

        at org.eclipse.jetty.websocket.common.io.AbstractWebSocketConnection.readParse(AbstractWebSocketConnection.java:602)

        at org.eclipse.jetty.websocket.common.io.AbstractWebSocketConnection.onFillable(AbstractWebSocketConnection.java:458)

        at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:534)

        at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:607)

        at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:536)

        at java.lang.Thread.run(Thread.java:745)

From what I can see all server messages are processed sequentially (always the same Jetty thread) while client side messages are received in different threads. It is possible there is an issue with concurrency in the client?

Rossen