dubbo RPC attachments java.util.ConcurrentModificationException

[shenjiaqing1]

hashmap改成ConcurrentHashMap

[chickenlj]

RpcInvocation 实例是在什么场景出现了被多线程共享的情况？

[shenjiaqing1]

RpcInvocation 实例是在什么场景出现了被多线程共享的情况？

有两个条件，条件一是dubbo开启异步回调，条件二是高并发的情况下会存在非常小的概率发生这样的问题。线程1和线程2共享一个map，线程1在操作for循环的时候，线程2有一定的概率会修改与线程1共享的map。

[shenjiaqing1]

RpcInvocation 实例是在什么场景出现了被多线程共享的情况？

我能理解为当存在同一个线程执行另外一个rpc调用的时候，就可能会发生前一个rpc异步回调的时候RpcContext被修改，是吗？

[CVnot]

就可能会发生前

@chickenlj @shenjiaqing1 我理解这个地方不应该会有并发问题的，因为一个线程发起完请求之后，AsyncRpcResult中存储了一份Threadlocal的对象，并且在ContextFilter进行了remove，所以即使这个这个线程在接收到下一个请求的同时，上一个请求返回了，也不会修改一个对象的。我看的代码版本是2.7.18

[CVnot]

我理解不会的，都是ThreadLocal的，上一个请求回来的对象和下一次请求的不是一个对象的，我们也遇到类似的问题，不过并不是这个地方

[giraffe-tree]

我也遇到的这个问题
consumer / provider 用的是都是 dubbo 2.7.9

org.apache.dubbo.rpc.RpcException: Failed to invoke the method inWithResult in the service xxxx.xxxxService. Tried 1 times of the providers [xxxx:17071] (1/68) from the registry xxxx:7400 on the consumer xxxx using the dubbo version 2.7.9. Last error is: null
        at org.apache.dubbo.rpc.cluster.support.FailoverClusterInvoker.doInvoke(FailoverClusterInvoker.java:113)
        at org.apache.dubbo.rpc.cluster.support.AbstractClusterInvoker.invoke(AbstractClusterInvoker.java:265)
        at org.apache.dubbo.rpc.cluster.interceptor.ClusterInterceptor.intercept(ClusterInterceptor.java:47)
        at org.apache.dubbo.rpc.cluster.support.wrapper.AbstractCluster$InterceptorInvokerNode.invoke(AbstractCluster.java:92)
        at org.apache.dubbo.rpc.cluster.support.wrapper.MockClusterInvoker.invoke(MockClusterInvoker.java:93)
        at org.apache.dubbo.registry.integration.InterfaceCompatibleRegistryProtocol$MigrationInvoker.invoke(InterfaceCompatibleRegistryProtocol.java:132)
        at org.apache.dubbo.rpc.proxy.InvokerInvocationHandler.invoke(InvokerInvocationHandler.java:83)
        at xxx 业务堆栈
        at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774)
        at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:750)
        at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
        at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1975)
        at org.apache.dubbo.rpc.protocol.dubbo.FutureAdapter.lambda$new$0(FutureAdapter.java:49)
        at java.util.concurrent.CompletableFuture.uniWhenComplete(CompletableFuture.java:774)
        at java.util.concurrent.CompletableFuture$UniWhenComplete.tryFire(CompletableFuture.java:750)
        at java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:488)
        at java.util.concurrent.CompletableFuture.complete(CompletableFuture.java:1975)
        at org.apache.dubbo.remoting.exchange.support.DefaultFuture.doReceived(DefaultFuture.java:208)
        at org.apache.dubbo.remoting.exchange.support.DefaultFuture.received(DefaultFuture.java:175)
        at org.apache.dubbo.remoting.exchange.support.DefaultFuture.received(DefaultFuture.java:163)
        at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.handleResponse(HeaderExchangeHandler.java:60)
        at org.apache.dubbo.remoting.exchange.support.header.HeaderExchangeHandler.received(HeaderExchangeHandler.java:181)
        at org.apache.dubbo.remoting.transport.DecodeHandler.received(DecodeHandler.java:51)
        at org.apache.dubbo.remoting.transport.dispatcher.ChannelEventRunnable.run(ChannelEventRunnable.java:57)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at java.lang.Thread.run(Thread.java:748)
Caused by: java.util.ConcurrentModificationException
        at java.util.HashMap$HashIterator.nextNode(HashMap.java:1445)
        at java.util.HashMap$EntryIterator.next(HashMap.java:1479)
        at java.util.HashMap$EntryIterator.next(HashMap.java:1477)
        at java.util.HashMap.putMapEntries(HashMap.java:512)
        at java.util.HashMap.putAll(HashMap.java:785)
        at org.apache.dubbo.rpc.RpcInvocation.addObjectAttachments(RpcInvocation.java:337)
        at org.apache.dubbo.rpc.protocol.AbstractInvoker.invoke(AbstractInvoker.java:160)
        at org.apache.dubbo.rpc.protocol.AsyncToSyncInvoker.invoke(AsyncToSyncInvoker.java:52)
        at org.apache.dubbo.rpc.listener.ListenerInvokerWrapper.invoke(ListenerInvokerWrapper.java:78)
        at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
        at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
        at org.apache.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java:89)
        at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
        at org.apache.dubbo.rpc.protocol.dubbo.filter.FutureFilter.invoke(FutureFilter.java:51)
        at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
        at org.apache.dubbo.rpc.filter.ConsumerContextFilter.invoke(ConsumerContextFilter.java:69)
        at org.apache.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:83)
        at org.apache.dubbo.rpc.protocol.InvokerWrapper.invoke(InvokerWrapper.java:56)
        at org.apache.dubbo.rpc.cluster.support.FailoverClusterInvoker.doInvoke(FailoverClusterInvoker.java:82)