記 Spring Cloud Gateway 內存溢出查詢過程
環境配置：
org.springframework.boot ： 2.1.4.RELEASE
org.springframework.cloud ：Greenwich.SR1
事故記錄：
由於網關存在 RequestBody 丟失的情況，顧採用了網上的通用解決方案，使用如下方式解決：
@Bean
public RouteLocator tpauditRoutes(RouteLocatorBuilder builder) {
return builder.routes().route("gateway-post", r -> r.order(1)
.method(HttpMethod.POST)
.and()
.readBody(String.class, requestBody -> {return true;}) # 重點在這
.and()
.path("/gateway/**")
.filters(f -> {f.stripPrefix(1);return f;})
.uri("lb://APP-API")).build();
}
測試環境，Spring Cloud Gateway 網關功能編寫完成。開始進行測試環境壓測。
正常採用梯度壓測方式，最高用戶峯值設置爲400併發。經歷兩輪時長10分鐘左右壓測，沒有異常情況出現。
中午吃飯時間，設置了1個小時的時間進行測試。回來的時候系統報出如下異常。
2019-08-12 15:06:07,296 1092208 [reactor-http-server-epoll-12] WARN io.netty.channel.AbstractChannelHandlerContext.warn:146 - An exception '{}' [enable DEBUG level for full stacktrace] was thrown by a user handler's exceptionCaught() method while handling the following exception:
io.netty.util.internal.OutOfDirectMemoryError: failed to allocate 16777216 byte(s) of direct memory (used: 503316487, max: 504889344)
at io.netty.util.internal.PlatformDependent.incrementMemoryCounter(PlatformDependent.java:640)
at io.netty.util.internal.PlatformDependent.allocateDirectNoCleaner(PlatformDependent.java:594)
at io.netty.buffer.PoolArena$DirectArena.allocateDirect(PoolArena.java:764)
at io.netty.buffer.PoolArena$DirectArena.newChunk(PoolArena.java:740)
at io.netty.buffer.PoolArena.allocateNormal(PoolArena.java:244)
at io.netty.buffer.PoolArena.allocate(PoolArena.java:214)
at io.netty.buffer.PoolArena.allocate(PoolArena.java:146)
at io.netty.buffer.PooledByteBufAllocator.newDirectBuffer(PooledByteBufAllocator.java:324)
at io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:185)
at io.netty.buffer.AbstractByteBufAllocator.directBuffer(AbstractByteBufAllocator.java:176)
at io.netty.buffer.AbstractByteBufAllocator.ioBuffer(AbstractByteBufAllocator.java:137)
at io.netty.channel.DefaultMaxMessagesRecvByteBufAllocator$MaxMessageHandle.allocate(DefaultMaxMessagesRecvByteBufAllocator.java:114)
at io.netty.channel.epoll.EpollRecvByteAllocatorHandle.allocate(EpollRecvByteAllocatorHandle.java:72)
at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:793)
at io.netty.channel.epoll.AbstractEpollChannel$AbstractEpollUnsafe$1.run(AbstractEpollChannel.java:382)
at io.netty.util.concurrent.AbstractEventExecutor.safeExecute(AbstractEventExecutor.java:163)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:404)
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:315)
at io.
當時一臉懵逼，馬上開始監控 Jvm 堆棧，減少jvm的內存空間，提升併發數以後，重啓項目重新壓測，項目啓動參數如下：
java -jar -Xmx1024M /opt/deploy/gateway-appapi/cloud-employ-gateway-0.0.5-SNAPSHOT.jar
↓↓↓↓修改爲↓↓↓↓
java -jar -Xmx512M /opt/deploy/gateway-appapi/cloud-employ-gateway-0.0.5-SNAPSHOT.jar
縮減了一半內存啓動，等待問題復現。等待3分鐘問題再次復現，但是同時Jvm卻的進行了Full GC。
EC EU OC OU MC MU CCSC CCSU YGC YGCT FGC FGCT
275456.0 100103.0 484864.0 50280.2 67672.0 64001.3 9088.0 8463.2 501 11.945 3 0.262
275968.0 25072.3 484864.0 47329.3 67672.0 63959.4 9088.0 8448.8 502 11.970 4 0.429
沒錯，在出現問題的時候，系統出現了Full Gc，但是OU並沒有達到觸發的原因。結合日誌中的 direct memory，想到了Jvm 中的堆外內存。使用 -XX:MaxDirectMemorySize 可以進行設置 Jvm 堆外內存大小，當 Direct ByteBuffer 分配的堆外內存到達指定大小後，即觸發Full GC。該值是有上限的，默認是64M，最大爲 sun.misc.VM.maxDirectMemory()。結合所有情況，表明堆外內存使用存在內存溢出的情況。
報錯內容爲Netty框架，新增以下配置，開啓Netty錯誤日誌打印：
-Dio.netty.leakDetection.targetRecords=40 #設置Records 上限
-Dio.netty.leakDetection.level=advanced #設置日誌級別
項目啓動，沒任何問題，開啓壓測後服務報出如下異常：
2019-08-13 14:59:01,656 18047 [reactor-http-nio-7] ERROR io.netty.util.ResourceLeakDetector.reportTracedLeak:317 - LEAK: ByteBuf.release() was not called before it's garbage-collected. See http://netty.io/wiki/reference-counted-objects.html for more information.
Recent access records:
#1:
org.springframework.core.io.buffer.NettyDataBuffer.release(NettyDataBuffer.java:301)
org.springframework.core.io.buffer.DataBufferUtils.release(DataBufferUtils.java:420)
org.springframework.core.codec.StringDecoder.decodeDataBuffer(StringDecoder.java:208)
org.springframework.core.codec.StringDecoder.decodeDataBuffer(StringDecoder.java:59)
org.springframework.core.codec.AbstractDataBufferDecoder.lambda$decodeToMono$1(AbstractDataBufferDecoder.java:68)
reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:107)
reactor.core.publisher.FluxContextStart$ContextStartSubscriber.onNext(FluxContextStart.java:103)
reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:287)
reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:331)
reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1505)
reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:123)
reactor.core.publisher.FluxJust$WeakScalarSubscription.request(FluxJust.java:101)
reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onSubscribe(MonoCollectList.java:90)
reactor.core.publisher.FluxJust.subscribe(FluxJust.java:70)
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reactor.core.publisher.MonoCollectList.subscribe(MonoCollectList.java:59)
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reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150)
reactor.core.publisher.FluxContextStart$ContextStartSubscriber.onNext(FluxContextStart.java:103)
reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:287)
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reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1505)
reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:123)
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reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252)
reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136)
reactor.netty.channel.FluxReceive.terminateReceiver(FluxReceive.java:372)
reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:196)
reactor.netty.channel.FluxReceive.onInboundComplete(FluxReceive.java:337)
reactor.netty.channel.ChannelOperations.onInboundComplete(ChannelOperations.java:333)
reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:453)
reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:141)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337)
reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:191)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337)
io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438)
io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:323)
io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:297)
io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337)
io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1408)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:930)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:677)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:612)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:529)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:491)
io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:905)
java.lang.Thread.run(Unknown Source)
#2:
io.netty.buffer.AdvancedLeakAwareByteBuf.nioBuffer(AdvancedLeakAwareByteBuf.java:712)
org.springframework.core.io.buffer.NettyDataBuffer.asByteBuffer(NettyDataBuffer.java:266)
org.springframework.core.codec.StringDecoder.decodeDataBuffer(StringDecoder.java:207)
org.springframework.core.codec.StringDecoder.decodeDataBuffer(StringDecoder.java:59)
org.springframework.core.codec.AbstractDataBufferDecoder.lambda$decodeToMono$1(AbstractDataBufferDecoder.java:68)
reactor.core.publisher.FluxMapFuseable$MapFuseableSubscriber.onNext(FluxMapFuseable.java:107)
reactor.core.publisher.FluxContextStart$ContextStartSubscriber.onNext(FluxContextStart.java:103)
reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:287)
reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:331)
reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1505)
reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:123)
reactor.core.publisher.FluxJust$WeakScalarSubscription.request(FluxJust.java:101)
reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onSubscribe(MonoCollectList.java:90)
reactor.core.publisher.FluxJust.subscribe(FluxJust.java:70)
reactor.core.publisher.FluxDefer.subscribe(FluxDefer.java:54)
reactor.core.publisher.MonoCollectList.subscribe(MonoCollectList.java:59)
reactor.core.publisher.MonoFilterFuseable.subscribe(MonoFilterFuseable.java:44)
reactor.core.publisher.MonoMapFuseable.subscribe(MonoMapFuseable.java:56)
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reactor.core.publisher.FluxContextStart$ContextStartSubscriber.onNext(FluxContextStart.java:103)
reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:287)
reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:331)
reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1505)
reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:123)
reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136)
reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252)
reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136)
reactor.netty.channel.FluxReceive.terminateReceiver(FluxReceive.java:372)
reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:196)
reactor.netty.channel.FluxReceive.onInboundComplete(FluxReceive.java:337)
reactor.netty.channel.ChannelOperations.onInboundComplete(ChannelOperations.java:333)
reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:453)
reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:141)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337)
reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:191)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337)
io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438)
io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:323)
io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:297)
io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337)
io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1408)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:930)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:677)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:612)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:529)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:491)
io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:905)
java.lang.Thread.run(Unknown Source)
#3:
io.netty.buffer.AdvancedLeakAwareByteBuf.slice(AdvancedLeakAwareByteBuf.java:82)
org.springframework.core.io.buffer.NettyDataBuffer.slice(NettyDataBuffer.java:260)
org.springframework.core.io.buffer.NettyDataBuffer.slice(NettyDataBuffer.java:42)
org.springframework.cloud.gateway.handler.predicate.ReadBodyPredicateFactory.lambda$null$0(ReadBodyPredicateFactory.java:102)
reactor.core.publisher.FluxDefer.subscribe(FluxDefer.java:46)
reactor.core.publisher.MonoCollectList.subscribe(MonoCollectList.java:59)
reactor.core.publisher.MonoFilterFuseable.subscribe(MonoFilterFuseable.java:44)
reactor.core.publisher.MonoMapFuseable.subscribe(MonoMapFuseable.java:56)
reactor.core.publisher.MonoSubscriberContext.subscribe(MonoSubscriberContext.java:47)
reactor.core.publisher.MonoMapFuseable.subscribe(MonoMapFuseable.java:59)
reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44)
reactor.core.publisher.MonoOnErrorResume.subscribe(MonoOnErrorResume.java:44)
reactor.core.publisher.MonoPeek.subscribe(MonoPeek.java:71)
reactor.core.publisher.MonoMap.subscribe(MonoMap.java:55)
reactor.core.publisher.MonoFlatMap$FlatMapMain.onNext(MonoFlatMap.java:150)
reactor.core.publisher.FluxContextStart$ContextStartSubscriber.onNext(FluxContextStart.java:103)
reactor.core.publisher.FluxMapFuseable$MapFuseableConditionalSubscriber.onNext(FluxMapFuseable.java:287)
reactor.core.publisher.FluxFilterFuseable$FilterFuseableConditionalSubscriber.onNext(FluxFilterFuseable.java:331)
reactor.core.publisher.Operators$MonoSubscriber.complete(Operators.java:1505)
reactor.core.publisher.MonoCollectList$MonoBufferAllSubscriber.onComplete(MonoCollectList.java:123)
reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136)
reactor.core.publisher.FluxPeek$PeekSubscriber.onComplete(FluxPeek.java:252)
reactor.core.publisher.FluxMap$MapSubscriber.onComplete(FluxMap.java:136)
reactor.netty.channel.FluxReceive.terminateReceiver(FluxReceive.java:372)
reactor.netty.channel.FluxReceive.drainReceiver(FluxReceive.java:196)
reactor.netty.channel.FluxReceive.onInboundComplete(FluxReceive.java:337)
reactor.netty.channel.ChannelOperations.onInboundComplete(ChannelOperations.java:333)
reactor.netty.http.server.HttpServerOperations.onInboundNext(HttpServerOperations.java:453)
reactor.netty.channel.ChannelOperationsHandler.channelRead(ChannelOperationsHandler.java:141)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337)
reactor.netty.http.server.HttpTrafficHandler.channelRead(HttpTrafficHandler.java:191)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337)
io.netty.channel.CombinedChannelDuplexHandler$DelegatingChannelHandlerContext.fireChannelRead(CombinedChannelDuplexHandler.java:438)
io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:323)
io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:297)
io.netty.channel.CombinedChannelDuplexHandler.channelRead(CombinedChannelDuplexHandler.java:253)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:337)
io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1408)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:359)
io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:345)
io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:930)
io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163)
io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:677)
io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:612)
io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:529)
io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:491)
io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:905)
java.lang.Thread.run(Unknown Source)
在 #3 中，我發現了一個眼熟的類，ReadBodyPredicateFactory.java ，還記得最開始的時候使用 readbody 配置麼？
這裏就是進行 cachedRequestBodyObject 的寫入類，追蹤一下Readbody源碼
/**
* This predicate is BETA and may be subject to change in a future release. A
* predicate that checks the contents of the request body
* @param inClass the class to parse the body to
* @param predicate a predicate to check the contents of the body
* @param <T> the type the body is parsed to
* @return a {@link BooleanSpec} to be used to add logical operators
*/
public <T> BooleanSpec readBody(Class<T> inClass, Predicate<T> predicate) {
return asyncPredicate(getBean(ReadBodyPredicateFactory.class)
.applyAsync(c -> c.setPredicate(inClass, predicate)));
}
異步調用的 ReadBodyPredicateFactory.applyAsync() 和 錯誤日誌中的
org.springframework.cloud.gateway.handler.predicate.ReadBodyPredicateFactory.lambda$null$0(ReadBodyPredicateFactory.java:102)
指向方法一致。查看源碼102行：
Flux<DataBuffer> cachedFlux = Flux.defer(() ->
Flux.just(dataBuffer.slice(0, dataBuffer.readableByteCount()))
);
此處 Spring Cloud Gateway 通過 dataBuffer.slice 切割出了新的 dataBuffer，但是通過 Netty 的內存檢測工具判斷，此處的 dataBuffer 並沒有被回收。錯誤如下，日誌很多容易被忽視。
ERROR io.netty.util.ResourceLeakDetector.reportTracedLeak:317 - LEAK: ByteBuf.release() was not called before it's garbage-collected. See http://netty.io/wiki/reference-counted-objects.html for more information.
找到問題那就要解決才行，嘗試修改源碼
@Override
@SuppressWarnings("unchecked")
public AsyncPredicate<ServerWebExchange> applyAsync(Config config) {
return exchange -> {
Class inClass = config.getInClass();
Object cachedBody = exchange.getAttribute(CACHE_REQUEST_BODY_OBJECT_KEY);
Mono<?> modifiedBody;
// We can only read the body from the request once, once that
// happens if we
// try to read the body again an exception will be thrown. The below
// if/else
// caches the body object as a request attribute in the
// ServerWebExchange
// so if this filter is run more than once (due to more than one
// route
// using it) we do not try to read the request body multiple times
if (cachedBody != null) {
try {
boolean test = config.predicate.test(cachedBody);
exchange.getAttributes().put(TEST_ATTRIBUTE, test);
return Mono.just(test);
} catch (ClassCastException e) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Predicate test failed because class in predicate "
+ "does not match the cached body object", e);
}
}
return Mono.just(false);
} else {
// Join all the DataBuffers so we have a single DataBuffer for
// the body
return DataBufferUtils.join(exchange.getRequest().getBody()).flatMap(dataBuffer -> {
// Update the retain counts so we can read the body twice,
// once to parse into an object
// that we can test the predicate against and a second time
// when the HTTP client sends
// the request downstream
// Note: if we end up reading the body twice we will run
// into
// a problem, but as of right
// now there is no good use case for doing this
DataBufferUtils.retain(dataBuffer);
// Make a slice for each read so each read has its own
// read/write indexes
Flux<DataBuffer> cachedFlux = Flux
.defer(() -> Flux.just(dataBuffer.slice(0, dataBuffer.readableByteCount())));
ServerHttpRequest mutatedRequest = new ServerHttpRequestDecorator(exchange.getRequest()) {
@Override
public Flux<DataBuffer> getBody() {
return cachedFlux;
}
};
# 新增如下代碼
DataBufferUtils.release(dataBuffer);
return ServerRequest.create(exchange.mutate().request(mutatedRequest).build(), messageReaders)
.bodyToMono(inClass).doOnNext(objectValue -> {
exchange.getAttributes().put(CACHE_REQUEST_BODY_OBJECT_KEY, objectValue);
exchange.getAttributes().put(CACHED_REQUEST_BODY_KEY, cachedFlux);
}).map(objectValue -> config.predicate.test(objectValue));
});
}
};
}
Spring Cloud Gateway 在配置的架構中，版本爲2.1.1，修改以上代碼後，啓動項目測試，問題沒有復現，正常運行。
同樣這個問題，也可以選擇升級 Spring Cloud Gateway 版本，在官方2.1.2版本中，此處代碼已被重構，升級後測試也完全正常。