The first stack trace's cause is truncated so I'm not sure what happened there, but the second includes "at io.grpc.netty.shaded.io.netty.handler.ssl.SslHandler.setHandshakeFailure(SslHandler.java:1792)" after " io.grpc.netty.shaded.io.netty.handler.ssl.SslHandler.channelInactive(SslHandler.java:1073) ", which I believe indicates that the channel - for an unknown (possibly truncated in the stack trace?) reason - moved to idle during the TLS handshake. As for why this would happen under load: just taking a guess, but is it possible your server is performing a blocking operation in the Netty event loop? I don't think MAX_CONCURRENT_STREAMS-related capacity issue would result in this stack trace, as the connection should be more or less cleanly rejected rather than moving a connected channel to inactive mid-handshake as suggested by the provided stacktrace.
Thanks, Eric On Wed, Jul 29, 2020 at 4:57 PM Ethan Cheng <[email protected]> wrote: > We had an incident earlier that when one of our client had improper retry > policy that leads to huge wave of requests to the server. Then all clients > started to see `this StatusRuntimeException: UNKNOWN: channel closed` at > client side. > > for one client, it was: > ``` > @400000005f0744ef2096858c java.util.concurrent.CompletionException: > io.grpc.StatusRuntimeException: UNKNOWN: channel closed > @400000005f0744ef2096858c Channel Pipeline: [SslHandler#0, > ProtocolNegotiators$ClientTlsHandler#0, > WriteBufferingAndExceptionHandler#0, DefaultChannelPipeline$TailContext#0] > @400000005f0744ef20968974 at > java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:331) > ~[?:?] > @400000005f0744ef2096df64 at > java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:346) > ~[?:?] > @400000005f0744ef2096df64 at > java.util.concurrent.CompletableFuture$UniApply.tryFire(CompletableFuture.java:632) > ~[?:?] > @400000005f0744ef2096e34c at > java.util.concurrent.CompletableFuture.postComplete(CompletableFuture.java:506) > [?:?] > @400000005f0744ef2096e34c at > java.util.concurrent.CompletableFuture.completeExceptionally(CompletableFuture.java:2088) > [?:?] > @400000005f0744ef2096ef04 at > io.grpc.stub.ClientCalls$StreamObserverToCallListenerAdapter.onClose(ClientCalls.java:449) > [grpc-stub-1.27.1.jar:1.27.1] > @400000005f0744ef2096fabc at > io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:426) > [grpc-core-1.29.0.jar:1.29.0] > @400000005f0744ef2096fea4 at > io.grpc.internal.ClientCallImpl.access$500(ClientCallImpl.java:66) > [grpc-core-1.29.0.jar:1.29.0] > @400000005f0744ef2096fea4 at > io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.close(ClientCallImpl.java:689) > [grpc-core-1.29.0.jar:1.29.0] > @400000005f0744ef20970674 at > io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.access$900(ClientCallImpl.java:577) > [grpc-core-1.29.0.jar:1.29.0] > @400000005f0744ef20970a5c at > io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInternal(ClientCallImpl.java:751) > [grpc-core-1.29.0.jar:1.29.0] > @400000005f0744ef20970a5c at > io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:740) > [grpc-core-1.29.0.jar:1.29.0] > @400000005f0744ef2097604c at > io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37) > [grpc-core-1.29.0.jar:1.29.0] > @400000005f0744ef20976434 at > io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123) > [grpc-core-1.29.0.jar:1.29.0] > @400000005f0744ef20976434 at > java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) > [?:?] > @400000005f0744ef20976fec at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) > [?:?] > @400000005f0744ef20976fec at java.lang.Thread.run(Thread.java:834) [?:?] > @400000005f0744ef20976fec Caused by: io.grpc.StatusRuntimeException: > UNKNOWN: channel closed > @400000005f0744ef209773d4 Channel Pipeline: [SslHandler#0, > ProtocolNegotiators$ClientTlsHandler#0, > WriteBufferingAndExceptionHandler#0, DefaultChannelPipeline$TailContext#0] > @400000005f0744ef209777bc at > io.grpc.Status.asRuntimeException(Status.java:533) > ~[grpc-api-1.29.0.jar:1.29.0] > @400000005f0744ef209777bc ... 12 more > ``` > > for another clients it was: > ``` > Caused by: java.nio.channels.ClosedChannelException > at > io.grpc.netty.shaded.io.grpc.netty.Utils.statusFromThrowable(Utils.java:168) > at > io.grpc.netty.shaded.io.grpc.netty.NettyClientTransport$5.operationComplete(NettyClientTransport.java:267) > at > io.grpc.netty.shaded.io.grpc.netty.NettyClientTransport$5.operationComplete(NettyClientTransport.java:261) > at > io.grpc.netty.shaded.io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:511) > at > io.grpc.netty.shaded.io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:485) > at > io.grpc.netty.shaded.io.netty.util.concurrent.DefaultPromise.notifyListeners(DefaultPromise.java:424) > at > io.grpc.netty.shaded.io.netty.util.concurrent.DefaultPromise.setFailure(DefaultPromise.java:112) > > java.util.concurrent.ExecutionException: io.grpc.StatusRuntimeException: > UNKNOWN: channel closed > at > java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:357) > ~[?:1.8.0_92] > at java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1895) > ~ > Caused by: io.grpc.StatusRuntimeException: UNKNOWN: channel closed > at io.grpc.Status.asRuntimeException(Status.java:533) > at > io.grpc.stub.ClientCalls$StreamObserverToCallListenerAdapter.onClose(ClientCalls.java:442) > io.grpc.PartialForwardingClientCallListener.onClose(PartialForwardingClientCallListener.java:39) > io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:23) > ~[sync-bid-strategy.jar:?] > at > io.grpc.ForwardingClientCallListener$SimpleForwardingClientCallListener.onClose(ForwardingClientCallListener.java:40) > ~[sync-bid-strategy.jar:?] > at > io.grpc.internal.CensusStatsModule$StatsClientInterceptor$1$1.onClose(CensusStatsModule.java:700) > ~[sync-bid-strategy.jar:?] > at > io.grpc.PartialForwardingClientCallListener.onClose(PartialForwardingClientCallListener.java:39) > at > io.grpc.ForwardingClientCallListener.onClose(ForwardingClientCallListener.java:23) > at > io.grpc.ForwardingClientCallListener$SimpleForwardingClientCallListener.onClose(ForwardingClientCallListener.java:40) > at > io.grpc.internal.CensusTracingModule$TracingClientInterceptor$1$1.onClose(CensusTracingModule.java:399) > at io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:507) > at io.grpc.internal.ClientCallImpl.access$300(ClientCallImpl.java:66) > at > io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.close(ClientCallImpl.java:627) > at > io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.access$700(ClientCallImpl.java:515) > at > io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInternal(ClientCallImpl.java:686) > at > io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:675) > at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37) > at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123) > at > java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) > ~[?:1.8.0_92] > at > java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) > ~[?:1.8.0_92] > at java.lang.Thread.run(Thread.java:745) ~[?:1.8.0_92] > Caused by: java.nio.channels.ClosedChannelException > at > io.grpc.netty.shaded.io.grpc.netty.Utils.statusFromThrowable(Utils.java:202) > ~ > at > io.grpc.netty.shaded.io.grpc.netty.WriteBufferingAndExceptionHandler.exceptionCaught(WriteBufferingAndExceptionHandler.java:86) > at > io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:297) > at > io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeExceptionCaught(AbstractChannelHandlerContext.java:276) > at > io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.fireExceptionCaught(AbstractChannelHandlerContext.java:268) > at > io.grpc.netty.shaded.io.grpc.netty.ProtocolNegotiators$ClientTlsHandler.userEventTriggered(ProtocolNegotiators.java:373) > io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeUserEventTriggered(AbstractChannelHandlerContext.java:341) > at > io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeUserEventTriggered(AbstractChannelHandlerContext.java:327) > at > io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.fireUserEventTriggered(AbstractChannelHandlerContext.java:319) > at > io.grpc.netty.shaded.io.netty.handler.ssl.SslUtils.handleHandshakeFailure(SslUtils.java:348) > at > io.grpc.netty.shaded.io.netty.handler.ssl.SslHandler.setHandshakeFailure(SslHandler.java:1792) > at > io.grpc.netty.shaded.io.netty.handler.ssl.SslHandler.channelInactive(SslHandler.java:1073) > at > io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:257) > at > io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:243) > at > io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.fireChannelInactive(AbstractChannelHandlerContext.java:236) > at > io.grpc.netty.shaded.io.netty.channel.DefaultChannelPipeline$HeadContext.channelInactive(DefaultChannelPipeline.java:1403) > at > io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:257) > at > io.grpc.netty.shaded.io.netty.channel.AbstractChannelHandlerContext.invokeChannelInactive(AbstractChannelHandlerContext.java:243) > at > io.grpc.netty.shaded.io.netty.channel.DefaultChannelPipeline.fireChannelInactive(DefaultChannelPipeline.java:912) > at > io.grpc.netty.shaded.io.netty.channel.AbstractChannel$AbstractUnsafe$8.run(AbstractChannel.java:827) > at > io.grpc.netty.shaded.io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163) > at > io.grpc.netty.shaded.io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:405) > at > io.grpc.netty.shaded.io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:338) > at > io.grpc.netty.shaded.io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:906) > at > io.grpc.netty.shaded.io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) > at > io.grpc.netty.shaded.io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) > at java.lang.Thread.run(Thread.java:745) ~[?:1.8.0_92] > Caused by: java.nio.channels.ClosedChannelException > at > io.grpc.netty.shaded.io.netty.handler.ssl.SslHandler.channelInactive(...)(Unknown > Source) > ``` > > The load is probably not very very high ~40RPS, but most of these requests > are server streaming and will transmit fairly large amount of data, meaning > that it will take considerable amount of time for each request to complete. > Are we hitting some kind of limitation of our server? I thought it could > be `MAX_CONCURRENT_STREAM`, but not sure the `MAX_CONCURRENT_STREAM` > applies to a client's connection to server, or the server's connections > overall. > > We are using grpc-netty-shaded(1.27.1). > > > -- > You received this message because you are subscribed to the Google Groups " > grpc.io" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/grpc-io/de583aee-62f7-4fba-9150-277e135e7658n%40googlegroups.com > <https://groups.google.com/d/msgid/grpc-io/de583aee-62f7-4fba-9150-277e135e7658n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "grpc.io" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. 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