我正在使用wso2esb + wso2mb + websockets将JMS消息从wso2mb转换为websockets。在我的性能测试期间（我试图从wso2mb向websocket发送7k消息）我收到了以下错误消息：
java.util.ConcurrentModificationException
at java.util.ArrayList$Itr.checkForComodification(ArrayList.java:901)
at java.util.ArrayList$Itr.next(ArrayList.java:851)
at org.wso2.carbon.inbound.endpoint.protocol.websocket.management.WebsocketSubscriberPathManager.broadcastOnSubscriberPath(WebsocketSubscriberPathManager.java:98)
at org.wso2.carbon.inbound.endpoint.protocol.websocket.InboundWebsocketResponseSender.handleSendBack(InboundWebsocketResponseSender.java:117)
at org.wso2.carbon.inbound.endpoint.protocol.websocket.InboundWebsocketResponseSender.sendBack(InboundWebsocketResponseSender.java:86)
at org.apache.synapse.core.axis2.Axis2Sender.sendBack(Axis2Sender.java:214)
at org.apache.synapse.mediators.builtin.RespondMediator.mediate(RespondMediator.java:35)
at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:97)
at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:59)
at org.apache.synapse.config.xml.AnonymousListMediator.mediate(AnonymousListMediator.java:37)
at org.apache.synapse.config.xml.SwitchCase.mediate(SwitchCase.java:69)
at org.apache.synapse.mediators.filters.SwitchMediator.mediate(SwitchMediator.java:119)
at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:97)
at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:59)
at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:158)
at org.apache.synapse.core.axis2.Axis2SynapseEnvironment.injectMessage(Axis2SynapseEnvironment.java:993)
at org.wso2.carbon.inbound.endpoint.protocol.websocket.InboundWebsocketSourceHandler.injectToSequence(InboundWebsocketSourceHandler.java:461)
at org.wso2.carbon.inbound.endpoint.protocol.websocket.InboundWebsocketSourceHandler.handleWebsocketPassthroughTextFrame(InboundWebsocketSourceHandler.java:346)
at org.wso2.carbon.inbound.endpoint.protocol.websocket.InboundWebsocketSourceHandler.handleWebSocketFrame(InboundWebsocketSourceHandler.java:242)
at org.wso2.carbon.inbound.endpoint.protocol.websocket.InboundWebsocketSourceHandler.channelRead(InboundWebsocketSourceHandler.java:132)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:308)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:294)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:308)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:294)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:244)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:308)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:294)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:846)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:131)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:468)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:382)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:354)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:110)
at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:137)
at java.lang.Thread.run(Thread.java:745)
你知道原因是什么吗？ 如果您想查看我的wso2esb项目，请告诉我。
非常感谢！
答案 0 :(得分：1)
连接新客户端后，会将其添加到地图中。如果在负载测试期间进行广播，则使用相同的映射来添加连接并用于广播目的。 这将导致并发修改异常。这是一种已知行为，我们建议您在运行时停止广播 性能测试。而是在性能测试期间仅写入一个通道，这将解决此问题。你可以在[1]找到代码进行进一步分析。