Avoid logging exception for closed session in AbstractSockJsSession

[mbenmass]

I have the following WebSocket configuration :

@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/game");
        registry.addEndpoint("/game").withSockJS();
    }

    @Override
    public void configureClientInboundChannel(ChannelRegistration registration) {
        registration.interceptors(subscriptionInterceptor());
    }

    @Override
    public void configureClientOutboundChannel(ChannelRegistration registration) {
    }

    @Override
    public void configureMessageBroker(MessageBrokerRegistry config) {
        config.enableSimpleBroker("/all","/user", "/table");
        config.setApplicationDestinationPrefixes("/app");
        config.setPreservePublishOrder(true);
    }

    @Override
    public void configureWebSocketTransport(WebSocketTransportRegistration registry) {
        registry.setMessageSizeLimit(5 * 1024 * 1024);
        registry.setSendBufferSizeLimit(5 * 1024 * 1024);
        registry.setSendTimeLimit(60 * 1000);
    }

    @Bean
    public SubscriptionInterceptor subscriptionInterceptor() {
        return new SubscriptionInterceptor();
    }
}

I have around 30 JS clients connected to my server using SockJS to send messages. From time to time I get the following error :

ERROR 14607 --- [io-8080-exec-17] .w.s.a.s.StandardWebSocketHandlerAdapter : Closing session due to exception for StandardWebSocketSession[id=11d93b6a-7de1-354b-4f33-5834a89da351, uri=ws://41.250.241.235:8080/game/352/qbd0x4z4/websocket]

org.springframework.web.socket.sockjs.SockJsMessageDeliveryException: Failed to deliver message(s) [SEND
destination:/app/table/7/request/newFrame
content-length:2

{}] for session qbd0x4z4; nested exception is org.springframework.web.socket.sockjs.SockJsMessageDeliveryException: Failed to deliver message(s) [SEND
destination:/app/table/7/request/newFrame
content-length:2

{}] for session qbd0x4z4: Session closed
    at org.springframework.web.socket.sockjs.transport.session.AbstractSockJsSession.delegateMessages(AbstractSockJsSession.java:391) ~[spring-websocket-5.1.14.RELEASE.jar:5.1.14.RELEASE]
    at org.springframework.web.socket.sockjs.transport.session.WebSocketServerSockJsSession.handleMessage(WebSocketServerSockJsSession.java:195) ~[spring-websocket-5.1.14.RELEASE.jar:5.1.14.RELEASE]
    at org.springframework.web.socket.sockjs.transport.handler.SockJsWebSocketHandler.handleTextMessage(SockJsWebSocketHandler.java:93) ~[spring-websocket-5.1.14.RELEASE.jar:5.1.14.RELEASE]
    at org.springframework.web.socket.handler.AbstractWebSocketHandler.handleMessage(AbstractWebSocketHandler.java:43) ~[spring-websocket-5.1.14.RELEASE.jar:5.1.14.RELEASE]
    at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter.handleTextMessage(StandardWebSocketHandlerAdapter.java:114) [spring-websocket-5.1.14.RELEASE.jar:5.1.14.RELEASE]
    at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter.access$000(StandardWebSocketHandlerAdapter.java:43) [spring-websocket-5.1.14.RELEASE.jar:5.1.14.RELEASE]
    at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter$3.onMessage(StandardWebSocketHandlerAdapter.java:85) [spring-websocket-5.1.14.RELEASE.jar:5.1.14.RELEASE]
    at org.springframework.web.socket.adapter.standard.StandardWebSocketHandlerAdapter$3.onMessage(StandardWebSocketHandlerAdapter.java:82) [spring-websocket-5.1.14.RELEASE.jar:5.1.14.RELEASE]
    at org.apache.tomcat.websocket.WsFrameBase.sendMessageText(WsFrameBase.java:395) [tomcat-embed-websocket-9.0.31.jar:9.0.31]
    at org.apache.tomcat.websocket.server.WsFrameServer.sendMessageText(WsFrameServer.java:119) [tomcat-embed-websocket-9.0.31.jar:9.0.31]
    at org.apache.tomcat.websocket.WsFrameBase.processDataText(WsFrameBase.java:495) [tomcat-embed-websocket-9.0.31.jar:9.0.31]
    at org.apache.tomcat.websocket.WsFrameBase.processData(WsFrameBase.java:294) [tomcat-embed-websocket-9.0.31.jar:9.0.31]
    at org.apache.tomcat.websocket.WsFrameBase.processInputBuffer(WsFrameBase.java:133) [tomcat-embed-websocket-9.0.31.jar:9.0.31]
    at org.apache.tomcat.websocket.server.WsFrameServer.onDataAvailable(WsFrameServer.java:82) [tomcat-embed-websocket-9.0.31.jar:9.0.31]
    at org.apache.tomcat.websocket.server.WsFrameServer.doOnDataAvailable(WsFrameServer.java:171) [tomcat-embed-websocket-9.0.31.jar:9.0.31]
    at org.apache.tomcat.websocket.server.WsFrameServer.notifyDataAvailable(WsFrameServer.java:151) [tomcat-embed-websocket-9.0.31.jar:9.0.31]
    at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler.upgradeDispatch(WsHttpUpgradeHandler.java:148) [tomcat-embed-websocket-9.0.31.jar:9.0.31]
    at org.apache.coyote.http11.upgrade.UpgradeProcessorInternal.dispatch(UpgradeProcessorInternal.java:54) [tomcat-embed-core-9.0.31.jar:9.0.31]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:59) [tomcat-embed-core-9.0.31.jar:9.0.31]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-9.0.31.jar:9.0.31]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1639) [tomcat-embed-core-9.0.31.jar:9.0.31]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.31.jar:9.0.31]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_121]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_121]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.31.jar:9.0.31]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_121]
Caused by: org.springframework.web.socket.sockjs.SockJsMessageDeliveryException: Failed to deliver message(s) [SEND
destination:/app/table/7/request/newFrame
content-length:2

{}] for session qbd0x4z4: Session closed
    at org.springframework.web.socket.sockjs.transport.session.AbstractSockJsSession.delegateMessages(AbstractSockJsSession.java:383) ~[spring-websocket-5.1.14.RELEASE.jar:5.1.14.RELEASE]
    ... 25 common frames omitted

I have no idea why I do get such an error as the logs are not self-explanatory.
I have been looking eveywhere in the internet, but I didn't find any solution to this issue, or at least someone who can explain what is happening.

Grateful if an experienced programmer with Spring and Websocket could help.

[rstoyanchev]

It means the session was closed simultaneously while a message was being processed and as a result it was dropped. We could avoid throwing the exception there but just do a debug message since there isn't much that could be done.

[mbenmass]

@rstoyanchev Thanks for your feedback, it makes sense.

Is there a way to catch this exception and avoid displaying it ?

[rstoyanchev]

We can make sure it's not displayed.

[rstoyanchev]

@mbenmass I intend to make a change for this.