SpringBoot WebClient memory leak when the response is not consumed in the filter

Hello everyone,

I’m running into a LEAK with WebClient. However I’m not able to reproduce the LEAK at all. The ERROR log is happening now and then in all live environments (roughly every 2-3 days).

I have read most of the other topics that got raised on the subject, but nothing seems to ressemble to my use case.

I’d be really grateful if anyone could help me out on this.

Expected Behavior

No LEAK

Actual Behavior

Standard stacktrace

LEAK: ByteBuf.release() was not called before it's garbage-collected. See https://netty.io/wiki/reference-counted-objects.html for more information.
Recent access records: 
Created at:
	io.netty.buffer.PooledByteBufAllocator.newDirectBuffer(PooledByteBufAllocator.java:385)
	io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:187)
	io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:178)
	io.netty.buffer.AbstractByteBufAllocator.buffer(AbstractByteBufAllocator.java:115)
	io.netty.handler.ssl.SslHandler.allocate(SslHandler.java:2212)
	io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1382)
	io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1282)
	io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1329)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:480)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
	io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	java.base/java.lang.Thread.run(Thread.java:834)

In “advanced” logging mode:

LEAK: ByteBuf.release() was not called before it's garbage-collected. See https://netty.io/wiki/reference-counted-objects.html for more information.
Recent access records: 
#1:
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:285)
	io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1533)
	io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1282)
	io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1329)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:480)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
	io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	java.base/java.lang.Thread.run(Thread.java:834)
#2:
	io.netty.buffer.AdvancedLeakAwareByteBuf.readRetainedSlice(AdvancedLeakAwareByteBuf.java:106)
	io.netty.handler.codec.http.HttpObjectDecoder.decode(HttpObjectDecoder.java:376)
	io.netty.handler.codec.http.HttpClientCodec$Decoder.decode(HttpClientCodec.java:225)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1533)
	io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1282)
	io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1329)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:480)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
	io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	java.base/java.lang.Thread.run(Thread.java:834)
#3:
	io.netty.buffer.AdvancedLeakAwareByteBuf.forEachByte(AdvancedLeakAwareByteBuf.java:670)
	io.netty.handler.codec.http.HttpObjectDecoder$HeaderParser.parse(HttpObjectDecoder.java:940)
	io.netty.handler.codec.http.HttpObjectDecoder.readHeaders(HttpObjectDecoder.java:616)
	io.netty.handler.codec.http.HttpObjectDecoder.decode(HttpObjectDecoder.java:258)
	io.netty.handler.codec.http.HttpClientCodec$Decoder.decode(HttpClientCodec.java:225)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1533)
	io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1282)
	io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1329)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:480)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
	io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	java.base/java.lang.Thread.run(Thread.java:834)
#4:
	io.netty.buffer.AdvancedLeakAwareByteBuf.forEachByte(AdvancedLeakAwareByteBuf.java:670)
	io.netty.handler.codec.http.HttpObjectDecoder$HeaderParser.parse(HttpObjectDecoder.java:940)
	io.netty.handler.codec.http.HttpObjectDecoder$LineParser.parse(HttpObjectDecoder.java:997)
	io.netty.handler.codec.http.HttpObjectDecoder.decode(HttpObjectDecoder.java:239)
	io.netty.handler.codec.http.HttpClientCodec$Decoder.decode(HttpClientCodec.java:225)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1533)
	io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1282)
	io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1329)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:480)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
	io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	java.base/java.lang.Thread.run(Thread.java:834)
#5:
	Hint: 'reactor.left.httpCodec' will handle the message from this point.
	io.netty.channel.DefaultChannelPipeline.touch(DefaultChannelPipeline.java:116)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1533)
	io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1282)
	io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1329)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:480)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
	io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	java.base/java.lang.Thread.run(Thread.java:834)
#6:
	io.netty.buffer.AdvancedLeakAwareByteBuf.internalNioBuffer(AdvancedLeakAwareByteBuf.java:736)
	io.netty.handler.ssl.SslHandler.toByteBuffer(SslHandler.java:1543)
	io.netty.handler.ssl.SslHandler.access$300(SslHandler.java:167)
	io.netty.handler.ssl.SslHandler$SslEngineType$3.unwrap(SslHandler.java:283)
	io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1387)
	io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1282)
	io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1329)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:480)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
	io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	java.base/java.lang.Thread.run(Thread.java:834)
#7:
	io.netty.buffer.AdvancedLeakAwareByteBuf.nioBufferCount(AdvancedLeakAwareByteBuf.java:706)
	io.netty.handler.ssl.SslHandler.toByteBuffer(SslHandler.java:1543)
	io.netty.handler.ssl.SslHandler.access$300(SslHandler.java:167)
	io.netty.handler.ssl.SslHandler$SslEngineType$3.unwrap(SslHandler.java:283)
	io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1387)
	io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1282)
	io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1329)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:480)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
	io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	java.base/java.lang.Thread.run(Thread.java:834)
Created at:
	io.netty.buffer.PooledByteBufAllocator.newDirectBuffer(PooledByteBufAllocator.java:385)
	io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:187)
	io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:178)
	io.netty.buffer.AbstractByteBufAllocator.buffer(AbstractByteBufAllocator.java:115)
	io.netty.handler.ssl.SslHandler.allocate(SslHandler.java:2212)
	io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1382)
	io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1282)
	io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1329)
	io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:508)
	io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:447)
	io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
	io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
	io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
	io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
	io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:795)
	io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:480)
	io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
	io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
	io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
	io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
	java.base/java.lang.Thread.run(Thread.java:834)
: 2 leak records were discarded because they were duplicates
: 22 leak records were discarded because the leak record count is targeted to 4. Use system property io.netty.leakDetection.targetRecords to increase the limit.

Client configuration

There is only one client in this component configured as such:

ClientContext snippet:

private static final Duration DEFAULT_CONNECTION_TIMEOUT = Duration.ofSeconds(1);
private static final Duration DEFAULT_READ_TIMEOUT = Duration.ofSeconds(30);

@Bean
public ClientHttpConnector clientHttpConnector() {
	return new ReactorClientHttpConnector(HttpClient.create()
		.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, (int) DEFAULT_CONNECTION_TIMEOUT.toMillis())
		.responseTimeout(DEFAULT_READ_TIMEOUT));
}

@Bean
public ICreditClient creditClient() {
	var componentUrl = componentClientConfiguration().getCreditUrl().toString();
	return new CreditClient(componentWebClientBuilder().baseUrl(componentUrl).build());
}

private WebClient.Builder componentWebClientBuilder() {

	return webClientBuilder.clone()
		.filter(renewTokenFilter())
		.filter(tokenFilter())
		.filter(new CorrelationIdHeaderFilter(configuration.getCorrelationIdSupplier()).filter())
		.filter(new PeerIdHeaderFilter(configuration.getPeerIdSupplier()).filter())
		.filter(new LoggingFilter().filter())
		.clientConnector(clientHttpConnector());
}

And used as follow:

CreditClient snippet:

@Override
@CircuitBreaker(name = "credit-client-save-credit")
@TimeLimiter(name = "credit-client-save-credit")
public Mono<CustomerCreditId> saveCredit(CustomerCreditCreation customerCreditCreation) {

	return webClient.post()
		.uri("/credit/v1/customer-credits")
		.bodyValue(customerCreditCreation)
		.retrieve()
		.bodyToMono(CustomerCreditId.class);
}

Side notes

I thought that it might be induced by the Timelimiter, but I couldn’t manage to reproduce the leak either. The connection seems to close itself correctly too.

CreditClientTest snippet:

@Slf4j
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.NONE)
@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
public class CreditClientTest {

	@Autowired
	private ICreditClient client;

	@Autowired
	ObjectMapper objectMapper;

	@RegisterExtension
	WireMockExtension wireMockExtension = new WireMockExtension();

	@Test
	void testSaveCredit() throws Exception {
		var credit = CustomerCreditCreation.builder().build();
		var creditId = CustomerCreditId.builder().customerId(1).creditId(1).build();

		stubFor(post(urlEqualTo("/credit/v1/customer-credits")).withRequestBody(
			WireMock.equalToJson(objectMapper.writeValueAsString(credit)))
			.willReturn(aResponse().withFixedDelay(1000)
				.withStatus(HttpStatus.OK.value())
				.withHeader(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE)
				.withBody(objectMapper.writeValueAsString(creditId))));

		try {
			var result = client.saveCredit(credit).block();
		} catch (Exception e) {
			log.info("No fallback", e);
		}
	}

	@SpringBootConfiguration
	@EnableAspectJAutoProxy
	@Import(value = { CircuitBreakerAutoConfiguration.class, RetryAutoConfiguration.class,
		TimeLimiterAutoConfiguration.class
	})
	public static class TestContext {

		@Bean
		public ObjectMapper objectMapper() {
			return new ObjectMapper();
		}

		@Autowired
		private TimeLimiterRegistry timeLimiterRegistry;

		@Bean
		public TimeLimiter creditClientTimeLimiter() {

			var config =
				TimeLimiterConfig.custom().timeoutDuration(Duration.ofMillis(250)).build();

			return timeLimiterRegistry.timeLimiter("credit-client-save-credit", config);
		}

		@Bean
		public CreditClient creditClient() {
			return new CreditClient(WebClient.builder().baseUrl("http://localhost:" + WireMockExtension.PORT).build());
		}
	}

}

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.4.4)

2021-04-14 15:38:03.258  INFO 48145 --- [           main] c.l.c.client.credit.CreditClientTest     : Starting CreditClientTest using Java 11.0.9.1 on MACC02ZL3G9LVDQ with PID 48145 (started by gabriel.dinant in /Users/gabriel.dinant/Documents/repositories/leshop/retention/cumulusvoucher/service)
2021-04-14 15:38:03.259 DEBUG 48145 --- [           main] c.l.c.client.credit.CreditClientTest     : Running with Spring Boot v2.4.4, Spring v5.3.5
2021-04-14 15:38:03.259  INFO 48145 --- [           main] c.l.c.client.credit.CreditClientTest     : The following profiles are active: test
2021-04-14 15:38:04.115 DEBUG 48145 --- [           main] reactor.netty.tcp.TcpResources           : [http] resources will use the default LoopResources: DefaultLoopResources {prefix=reactor-http, daemon=true, selectCount=12, workerCount=12}
2021-04-14 15:38:04.115 DEBUG 48145 --- [           main] reactor.netty.tcp.TcpResources           : [http] resources will use the default ConnectionProvider: reactor.netty.resources.DefaultPooledConnectionProvider@5d66e944
2021-04-14 15:38:04.267  INFO 48145 --- [           main] c.l.c.client.credit.CreditClientTest     : Started CreditClientTest in 1.294 seconds (JVM running for 2.622)
2021-04-14 15:38:04.511  INFO 48145 --- [           main] org.eclipse.jetty.server.Server          : jetty-9.4.38.v20210224; built: 2021-02-24T20:25:07.675Z; git: 288f3cc74549e8a913bf363250b0744f2695b8e6; jvm 11.0.9.1+1
2021-04-14 15:38:04.525  INFO 48145 --- [           main] o.e.jetty.server.handler.ContextHandler  : Started o.e.j.s.ServletContextHandler@42d236fb{/__admin,null,AVAILABLE}
2021-04-14 15:38:04.527  INFO 48145 --- [           main] o.e.jetty.server.handler.ContextHandler  : Started o.e.j.s.ServletContextHandler@ba1f559{/,null,AVAILABLE}
2021-04-14 15:38:04.547  INFO 48145 --- [           main] o.e.jetty.server.AbstractConnector       : Started NetworkTrafficServerConnector@1da6ee17{HTTP/1.1, (http/1.1)}{0.0.0.0:9095}
2021-04-14 15:38:04.548  INFO 48145 --- [           main] org.eclipse.jetty.server.Server          : Started @2903ms
2021-04-14 15:38:04.748  INFO 48145 --- [qtp305552520-24] o.e.j.s.handler.ContextHandler.__admin   : RequestHandlerClass from context returned com.github.tomakehurst.wiremock.http.AdminRequestHandler. Normalized mapped under returned 'null'
2021-04-14 15:38:04.982 DEBUG 48145 --- [           main] r.netty.resources.DefaultLoopIOUring     : Default io_uring support : false
2021-04-14 15:38:04.986 DEBUG 48145 --- [           main] r.netty.resources.DefaultLoopEpoll       : Default Epoll support : false
2021-04-14 15:38:04.986 DEBUG 48145 --- [           main] r.netty.resources.DefaultLoopKQueue      : Default KQueue support : false
2021-04-14 15:38:05.512 DEBUG 48145 --- [           main] r.n.resources.PooledConnectionProvider   : Creating a new [http] client pool [PoolFactory{evictionInterval=PT0S, leasingStrategy=fifo, maxConnections=500, maxIdleTime=-1, maxLifeTime=-1, metricsEnabled=false, pendingAcquireMaxCount=1000, pendingAcquireTimeout=45000}] for [localhost:9095]
2021-04-14 15:38:05.620 DEBUG 48145 --- [ctor-http-nio-2] r.n.r.DefaultPooledConnectionProvider    : [id:12019d3e] Created a new pooled channel, now: 1 active connections, 0 inactive connections and 0 pending acquire requests.
2021-04-14 15:38:05.620  INFO 48145 --- [           main] c.l.c.client.credit.CreditClientTest     : No fallback

reactor.core.Exceptions$ReactiveException: java.util.concurrent.TimeoutException: Did not observe any item or terminal signal within 250ms in 'flatMap' (and no fallback has been configured)
	at reactor.core.Exceptions.propagate(Exceptions.java:392) ~[reactor-core-3.4.4.jar:3.4.4]
	at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:97) ~[reactor-core-3.4.4.jar:3.4.4]
	at reactor.core.publisher.Mono.block(Mono.java:1703) ~[reactor-core-3.4.4.jar:3.4.4]
	at com.leshop.cumulusvoucher.client.credit.CreditClientTest.testSaveCredit(CreditClientTest.java:77) ~[test-classes/:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:566) ~[na:na]
	at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:688) ~[junit-platform-commons-1.7.1.jar:1.7.1]
	at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:210) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:206) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:131) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:65) ~[junit-jupiter-engine-5.7.1.jar:5.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1541) ~[na:na]
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1541) ~[na:na]
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51) ~[junit-platform-engine-1.7.1.jar:1.7.1]
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:108) ~[junit-platform-launcher-1.7.1.jar:1.7.1]
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88) ~[junit-platform-launcher-1.7.1.jar:1.7.1]
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54) ~[junit-platform-launcher-1.7.1.jar:1.7.1]
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67) ~[junit-platform-launcher-1.7.1.jar:1.7.1]
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52) ~[junit-platform-launcher-1.7.1.jar:1.7.1]
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:96) ~[junit-platform-launcher-1.7.1.jar:1.7.1]
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:75) ~[junit-platform-launcher-1.7.1.jar:1.7.1]
	at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71) ~[junit5-rt.jar:na]
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33) ~[junit-rt.jar:na]
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220) ~[junit-rt.jar:na]
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53) ~[junit-rt.jar:na]
	Suppressed: java.lang.Exception: #block terminated with an error
		at reactor.core.publisher.BlockingSingleSubscriber.blockingGet(BlockingSingleSubscriber.java:99) ~[reactor-core-3.4.4.jar:3.4.4]
		... 67 common frames omitted
Caused by: java.util.concurrent.TimeoutException: Did not observe any item or terminal signal within 250ms in 'flatMap' (and no fallback has been configured)
	at reactor.core.publisher.FluxTimeout$TimeoutMainSubscriber.handleTimeout(FluxTimeout.java:294) ~[reactor-core-3.4.4.jar:3.4.4]
	at reactor.core.publisher.FluxTimeout$TimeoutMainSubscriber.doTimeout(FluxTimeout.java:279) ~[reactor-core-3.4.4.jar:3.4.4]
	at reactor.core.publisher.FluxTimeout$TimeoutTimeoutSubscriber.onNext(FluxTimeout.java:418) ~[reactor-core-3.4.4.jar:3.4.4]
	at reactor.core.publisher.FluxOnErrorResume$ResumeSubscriber.onNext(FluxOnErrorResume.java:79) ~[reactor-core-3.4.4.jar:3.4.4]
	at reactor.core.publisher.MonoDelay$MonoDelayRunnable.run(MonoDelay.java:119) ~[reactor-core-3.4.4.jar:3.4.4]
	at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:68) ~[reactor-core-3.4.4.jar:3.4.4]
	at reactor.core.scheduler.SchedulerTask.call(SchedulerTask.java:28) ~[reactor-core-3.4.4.jar:3.4.4]
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
	at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304) ~[na:na]
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
	at java.base/java.lang.Thread.run(Thread.java:834) ~[na:na]

2021-04-14 15:38:05.664 DEBUG 48145 --- [ctor-http-nio-2] reactor.netty.transport.TransportConfig  : [id:12019d3e] Initialized pipeline DefaultChannelPipeline{(reactor.left.httpCodec = io.netty.handler.codec.http.HttpClientCodec), (reactor.left.httpDecompressor = io.netty.handler.codec.http.HttpContentDecompressor), (reactor.right.reactiveBridge = reactor.netty.channel.ChannelOperationsHandler)}
2021-04-14 15:38:05.698 DEBUG 48145 --- [ctor-http-nio-2] r.n.r.DefaultPooledConnectionProvider    : [id:12019d3e, L:/127.0.0.1:61436 - R:localhost/127.0.0.1:9095] Registering pool release on close event for channel
2021-04-14 15:38:05.699 DEBUG 48145 --- [ctor-http-nio-2] r.n.r.DefaultPooledConnectionProvider    : [id:12019d3e, L:/127.0.0.1:61436 - R:localhost/127.0.0.1:9095] Channel connected, now: 1 active connections, 0 inactive connections and 0 pending acquire requests.
2021-04-14 15:38:05.700 DEBUG 48145 --- [ctor-http-nio-2] r.n.r.DefaultPooledConnectionProvider    : [id:12019d3e, L:/127.0.0.1:61436 - R:localhost/127.0.0.1:9095] onStateChange(PooledConnection{channel=[id: 0x12019d3e, L:/127.0.0.1:61436 - R:localhost/127.0.0.1:9095]}, [connected])
2021-04-14 15:38:05.710 DEBUG 48145 --- [ctor-http-nio-2] r.n.r.DefaultPooledConnectionProvider    : [id:12019d3e-1, L:/127.0.0.1:61436 - R:localhost/127.0.0.1:9095] onStateChange(GET{uri=/, connection=PooledConnection{channel=[id: 0x12019d3e, L:/127.0.0.1:61436 - R:localhost/127.0.0.1:9095]}}, [configured])
2021-04-14 15:38:05.719 DEBUG 48145 --- [ctor-http-nio-2] r.n.r.DefaultPooledConnectionProvider    : [id:12019d3e-1, L:/127.0.0.1:61436 ! R:localhost/127.0.0.1:9095] Channel closed, now: 0 active connections, 0 inactive connections and 0 pending acquire requests.
2021-04-14 15:38:05.720 DEBUG 48145 --- [ctor-http-nio-2] r.netty.http.client.HttpClientConnect    : [id:12019d3e-1, L:/127.0.0.1:61436 ! R:localhost/127.0.0.1:9095] Handler is being applied: {uri=http://localhost:9095/credit/v1/customer-credits, method=POST}
2021-04-14 15:38:05.723 DEBUG 48145 --- [ctor-http-nio-2] r.n.r.DefaultPooledConnectionProvider    : [id:12019d3e-1, L:/127.0.0.1:61436 ! R:localhost/127.0.0.1:9095] onStateChange(POST{uri=/credit/v1/customer-credits, connection=PooledConnection{channel=[id: 0x12019d3e, L:/127.0.0.1:61436 ! R:localhost/127.0.0.1:9095]}}, [request_prepared])
2021-04-14 15:38:05.743 DEBUG 48145 --- [ctor-http-nio-2] r.n.r.DefaultPooledConnectionProvider    : [id:12019d3e-1, L:/127.0.0.1:61436 ! R:localhost/127.0.0.1:9095] onStateChange(POST{uri=/credit/v1/customer-credits, connection=PooledConnection{channel=[id: 0x12019d3e, L:/127.0.0.1:61436 ! R:localhost/127.0.0.1:9095]}}, [disconnecting])
2021-04-14 15:38:06.634  INFO 48145 --- [           main] o.e.jetty.server.AbstractConnector       : Stopped NetworkTrafficServerConnector@1da6ee17{HTTP/1.1, (http/1.1)}{0.0.0.0:9095}
2021-04-14 15:38:06.635  INFO 48145 --- [           main] o.e.jetty.server.handler.ContextHandler  : Stopped o.e.j.s.ServletContextHandler@ba1f559{/,null,STOPPED}
2021-04-14 15:38:06.635  INFO 48145 --- [           main] o.e.jetty.server.handler.ContextHandler  : Stopped o.e.j.s.ServletContextHandler@42d236fb{/__admin,null,STOPPED}

Reactor version(s) used:

Reactor-netty: 1.0.5 (spring-boot-starter-webflux)

Other relevant libraries versions (eg. netty, …):

Springboot: 2.4.4 Spring: 5.3.5 Resilence4j: 1.7.0

JVM version (java -version):

openjdk version “11.0.9.1” 2020-11-04 OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.9.1+1) OpenJDK 64-Bit Server VM AdoptOpenJDK (build 11.0.9.1+1, mixed mode)

OS and version (eg. uname -a):

Linux cumulusvoucher-34-d4gwj 3.10.0-1062.12.1.el7.x86_64 #1 SMP Thu Dec 12 06:44:49 EST 2019 x86_64 x86_64 x86_64 GNU/Linux

Issue Analytics

State:
Created 2 years ago
Comments:13 (7 by maintainers)

Top GitHub Comments

2reactions

rstoyanchevcommented, Apr 16, 2021

WebClient is a thin facade around a chain of filters with an ExchangeFunction at the end to call the ClientHttpConnector and make the request. Something like this:

WebClient request building -> [filter1 -> filter2 -> … -> ExchangeFunction/ClientHttpConnector] -> WebClient response handling

The exchange method in an ExchangeFilterFunction is indeed not deprecated, but when you operate on that level, specifically when you do some handling in the after phase, you are effectively taking over the response. Consider that WebClient is waiting for a Mono<ClientResponse> and if that never delivers but errors instead, it prevents WebClient from even seeing that there was a response.

Handle exceptions very carefully at that level and consume the response or call response.releaseBody().

0reactions

gdinantcommented, Apr 21, 2021

Perfect then, closing the issue 😉.

Thanks for your help!