DataBufferUtils#join could leak buffers in case of error from the source, How can I fix this memory leak issue?

[carl-HelloWorld]

spring-projects/spring-framework#34113

[violetagg]

@carl-HelloWorld Please follow this FAQ https://projectreactor.io/docs/netty/release/reference/appendices.html#faq.memory-leaks and provide the extended logs.

[carl-HelloWorld]

the first step requires setting the startup parameters:

-Dio.netty.leakDetection.level = debug

-Dspring.codec.max-in-memory-size = 1

Step 2: Send a request in an endless loop, the length of the request body is greater than 1, and then io.netty.util.ResourceLeakDetector#reportLeak will print the memory leak log、

Below is the source code address:
https://github.com/carl-HelloWorld/spring-gateway-leak-demo.git

First of all, you need to make a break point in the following places：
ResourceLeakDetector.reportUntracedLeak，
The memory leak log will appear within a minute

2024-12-18 17:53:18.498 logback [reactor-http-nio-62024-12-18 17:53:18.498 logback [reactor-http-nio-6] ERROR io.netty.util.ResourceLeakDetector - 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:
https://github.com/spring-projects/spring-framework/pull/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.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
java.lang.Thread.run(Thread.java:750)
https://github.com/spring-projects/spring-framework/pull/2:
io.netty.buffer.AdvancedLeakAwareByteBuf.readRetainedSlice(AdvancedLeakAwareByteBuf.java:106)
io.netty.handler.codec.http.HttpObjectDecoder.decode(HttpObjectDecoder.java:333)
io.netty.handler.codec.http.HttpServerCodec$HttpServerRequestDecoder.decode(HttpServerCodec.java:123)
io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:507)
io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:446)
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.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
java.lang.Thread.run(Thread.java:750)
https://github.com/spring-projects/spring-framework/pull/3:
io.netty.buffer.AdvancedLeakAwareByteBuf.forEachByte(AdvancedLeakAwareByteBuf.java:670)
io.netty.handler.codec.http.HttpObjectDecoder$HeaderParser.parse(HttpObjectDecoder.java:908)
io.netty.handler.codec.http.HttpObjectDecoder.readHeaders(HttpObjectDecoder.java:593)
io.netty.handler.codec.http.HttpObjectDecoder.decode(HttpObjectDecoder.java:255)
io.netty.handler.codec.http.HttpServerCodec$HttpServerRequestDecoder.decode(HttpServerCodec.java:123)
io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:507)
io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:446)
io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:251)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
io.netty.channel.DefaultChannelPipeline$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.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
java.lang.Thread.run(Thread.java:750)
https://github.com/spring-projects/spring-framework/pull/4:
io.netty.buffer.AdvancedLeakAwareByteBuf.forEachByte(AdvancedLeakAwareByteBuf.java:670)
io.netty.handler.codec.http.HttpObjectDecoder$HeaderParser.parse(HttpObjectDecoder.java:908)
io.netty.handler.codec.http.HttpObjectDecoder$LineParser.parse(HttpObjectDecoder.java:965)
io.netty.handler.codec.http.HttpObjectDecoder.decode(HttpObjectDecoder.java:236)
io.netty.handler.codec.http.HttpServerCodec$HttpServerRequestDecoder.decode(HttpServerCodec.java:123)
io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:507)
io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:446)
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.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
java.lang.Thread.run(Thread.java:750)
https://github.com/spring-projects/spring-framework/pull/5:
Hint: 'reactor.left.httpCodec' will handle the message from this point.
io.netty.channel.DefaultChannelPipeline.touch(DefaultChannelPipeline.java:116)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
io.netty.channel.DefaultChannelPipeline$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.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
java.lang.Thread.run(Thread.java:750)
https://github.com/spring-projects/spring-framework/pull/6:
Hint: 'DefaultChannelPipeline$HeadContext#0' 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.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:655)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:581)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:493)
io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
java.lang.Thread.run(Thread.java:750)
https://github.com/spring-projects/spring-framework/pull/7:
io.netty.buffer.AdvancedLeakAwareByteBuf.writeBytes(AdvancedLeakAwareByteBuf.java:634)
io.netty.channel.socket.nio.NioSocketChannel.doReadBytes(NioSocketChannel.java:350)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:151)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:719)

[violetagg]

Below is the source code address: https://github.com/carl-HelloWorld/spring-gateway-leak-demo.git

This demo is based on versions that are out of OSS support. Please upgrade to supported versions.
https://github.com/carl-HelloWorld/spring-gateway-leak-demo/blob/cloud2.x-gateway/pom.xml

[carl-HelloWorld]

thranks you，I've now upgraded to the supported version，And the problem is reproduced as well，Please pull the latest source code again

he first step requires setting the startup parameters:

-Dio.netty.leakDetection.level = debug

-Dspring.codec.max-in-memory-size = 1

Step 2: Send a request in an endless loop, the length of the request body is greater than 1, and then io.netty.util.ResourceLeakDetector#reportLeak will print the memory leak log、

[violetagg]

@carl-HelloWorld Is it correct to say that basically you cache the body twice?
The first time, it is cached by ServerWebExchangeUtils.cacheRequestBody without any memory limitation https://github.com/carl-HelloWorld/spring-gateway-leak-demo/blob/54681069c2d1dcd0bab6986b81ca696f0f5429d6/spring-cloud-gateway/src/main/java/com/hello/filter/RequestBodyLogGlobalFilter.java#L43
The second time, it is cached by your requestBodyStoreToExchange with memory limitation https://github.com/carl-HelloWorld/spring-gateway-leak-demo/blob/54681069c2d1dcd0bab6986b81ca696f0f5429d6/spring-cloud-gateway/src/main/java/com/hello/filter/RequestBodyLogGlobalFilter.java#L64

Do you delete the cache created by ServerWebExchangeUtils.cacheRequestBody?

[violetagg]

@carl-HelloWorld Ensure that your filter is after org.springframework.cloud.gateway.filter.RemoveCachedBodyFilter as ordering, for example change the ordering like below and you will not see leaks anymore. Closing as invalid.

    @Override
    public int getOrder() {
        return Ordered.HIGHEST_PRECEDENCE + 1500;
    }