TEXT_PARTIAL_WRITING exception

[fschmuck]

I am using spring graphql with webflux and sometimes receive this exception.
I don't know whats the cause behind it. The websocket just forwards data from a MongoDB changeset.

Thanks in advance!

java.lang.IllegalStateException: The remote endpoint was in state [TEXT_PARTIAL_WRITING] which is an invalid state for called method
        at org.apache.tomcat.websocket.WsRemoteEndpointImplBase$StateMachine.checkState(WsRemoteEndpointImplBase.java:1274) ~[tomcat-embed-websocket-9.0.63.jar:9.0.63]
        at org.apache.tomcat.websocket.WsRemoteEndpointImplBase$StateMachine.textPartialStart(WsRemoteEndpointImplBase.java:1231) ~[tomcat-embed-websocket-9.0.63.jar:9.0.63]
        at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.sendPartialString(WsRemoteEndpointImplBase.java:226) ~[tomcat-embed-websocket-9.0.63.jar:9.0.63]
        at org.apache.tomcat.websocket.WsRemoteEndpointBasic.sendText(WsRemoteEndpointBasic.java:49) ~[tomcat-embed-websocket-9.0.63.jar:9.0.63]
        at org.springframework.web.socket.adapter.standard.StandardWebSocketSession.sendTextMessage(StandardWebSocketSession.java:215) ~[spring-websocket-5.3.20.jar:5.3.20]
        at org.springframework.web.socket.adapter.AbstractWebSocketSession.sendMessage(AbstractWebSocketSession.java:106) ~[spring-websocket-5.3.20.jar:5.3.20]
        at org.springframework.graphql.server.webmvc.GraphQlWebSocketHandler$SendMessageSubscriber.hookOnNext(GraphQlWebSocketHandler.java:556) ~[spring-graphql-1.0.0.jar:1.0.0]
        at org.springframework.graphql.server.webmvc.GraphQlWebSocketHandler$SendMessageSubscriber.hookOnNext(GraphQlWebSocketHandler.java:534) ~[spring-graphql-1.0.0.jar:1.0.0]
        at reactor.core.publisher.BaseSubscriber.onNext(BaseSubscriber.java:160) ~[reactor-core-3.4.18.jar:3.4.18]
        at reactor.core.publisher.FluxPublishOn$PublishOnSubscriber.runAsync(FluxPublishOn.java:440) ~[reactor-core-3.4.18.jar:3.4.18]
        at reactor.core.publisher.FluxPublishOn$PublishOnSubscriber.run(FluxPublishOn.java:527) ~[reactor-core-3.4.18.jar:3.4.18]
        at reactor.core.scheduler.WorkerTask.call(WorkerTask.java:84) ~[reactor-core-3.4.18.jar:3.4.18]
        at reactor.core.scheduler.WorkerTask.call(WorkerTask.java:37) ~[reactor-core-3.4.18.jar:3.4.18]
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
        at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304) ~[na:na]
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[na:na]
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[na:na]
        at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]

[rstoyanchev]

From the stacktrace, you're using Tomcat, Spring MVC, and spring-websocket, i.e. not a WebFlux server.

Aside from that, can you provide the Tomcat version? It's hard to match the exact line number to the Tomcat source. It sounds like there might be some concurrent writing to the socket on the same connection. We do serialize Next messages so it shouldn't happen from that. Could it be the client is sending Ping messages?

[fschmuck]

I am sorry. I must have mixed up something with my dependencies. I will try to switch to webflux.

Yes the client is sending ping messages and the tomcat version seems to be 9.0.63.

[rstoyanchev]

I don't know how easy it is to reproduce, but could you try if turning off pings makes a difference, or reversely you can make them more frequent, and that could get it to occur more often.

Either way, we should make Next and Pong message be sent serially, so I'll schedule this to be done..

[rstoyanchev]

I've made a fix, but would be great if you could give it a try and confirm. We're releasing this as part of 1.2.3 tomorrow, but until then you can also try with 1.2.3-SNAPSHOT.

[fschmuck]

Did just a quick test but I think it looks good. Thank you very much!