java.net.SocketTimeoutException 在 org.apache.tomcat.util.net.NioBlockingSelector

Question

我有一个在 tomcat 上运行的 spring boot 应用程序。该应用程序非常轻量级，如 15 毫秒 SLA，但服务于每秒 5000 到 10000 之间的良好流量。典型的传入有效负载大小在 1 到 1.5Kb 之间。

对于很少的请求（例如< 5) I see the below exception while JSON deserializing the incoming payload. Struggling to triage beyond some point.

异常发生在它开始反序列化 20 秒后，因为 20 秒是 SO_timeout。

但我不知道它为什么要等待，因为我发现它读取了所有数据并填充了POJO。我是通过在POJO的setter方法中添加一条日志发现的。日志显示所有数据都在一毫秒内反序列化，但不知何故 NioBlockingSelector 正在等待读取。

我在 Pojo 的 setter 方法中编写的代码，有助于识别它是在接收数据之前还是之后卡住。它收到了所有数据。

public void setValue(String value){
  this.value = value;
  Sysout.out.println(System.currentTimeMillis())
}

st=java.net.SocketTimeoutException
at org.apache.tomcat.util.net.NioBlockingSelector.read(NioBlockingSelector.java:204)
at org.apache.tomcat.util.net.NioSelectorPool.read(NioSelectorPool.java:221)
at org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper.fillReadBuffer(NioEndpoint.java:1226)
at org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper.read(NioEndpoint.java:1144)
at org.apache.coyote.http11.Http11InputBuffer.fill(Http11InputBuffer.java:735)
at org.apache.coyote.http11.Http11InputBuffer.access$300(Http11InputBuffer.java:41)
at org.apache.coyote.http11.Http11InputBuffer$SocketInputBuffer.doRead(Http11InputBuffer.java:1070)
at org.apache.coyote.http11.filters.IdentityInputFilter.doRead(IdentityInputFilter.java:102)
at org.apache.coyote.http11.Http11InputBuffer.doRead(Http11InputBuffer.java:246)
at org.apache.coyote.Request.doRead(Request.java:551)
at org.apache.catalina.connector.InputBuffer.realReadBytes(InputBuffer.java:336)
at org.apache.catalina.connector.InputBuffer.checkByteBufferEof(InputBuffer.java:632)
at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:362)
at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:132)
at org.glassfish.jersey.message.internal.EntityInputStream.read(EntityInputStream.java:103)
at org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$UnCloseableInputStream.read(ReaderInterceptorExecutor.java:297)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._loadMore(UTF8StreamJsonParser.java:205)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._skipWSOrEnd(UTF8StreamJsonParser.java:2932)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser.nextFieldName(UTF8StreamJsonParser.java:964)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:376)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:159)
at com.fasterxml.jackson.databind.ObjectReader._bind(ObjectReader.java:1574)
at com.fasterxml.jackson.databind.ObjectReader.readValue(ObjectReader.java:965)
at org.glassfish.jersey.jackson.internal.jackson.jaxrs.base.ProviderBase.readFrom(ProviderBase.java:838)
at org.glassfish.jersey.jackson.internal.jackson.jaxrs.json.JacksonJaxbJsonProvider.readFrom(JacksonJaxbJsonProvider.java:45)
at org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$TerminalReaderInterceptor.invokeReadFrom(ReaderInterceptorExecutor.java:257)
at org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$TerminalReaderInterceptor.aroundReadFrom(ReaderInterceptorExecutor.java:236)
at org.glassfish.jersey.message.internal.ReaderInterceptorExecutor.proceed(ReaderInterceptorExecutor.java:156)
at org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundReadFrom(MappableExceptionWrapperInterceptor.java:73)
at org.glassfish.jersey.message.internal.ReaderInterceptorExecutor.proceed(ReaderInterceptorExecutor.java:156)
at org.glassfish.jersey.message.internal.MessageBodyFactory.readFrom(MessageBodyFactory.java:1091)
at org.glassfish.jersey.message.internal.InboundMessageContext.readEntity(InboundMessageContext.java:874)
at org.glassfish.jersey.server.ContainerRequest.readEntity(ContainerRequest.java:271)
at org.glassfish.jersey.server.internal.inject.EntityParamValueParamProvider$EntityValueSupplier.apply(EntityParamValueParamProvider.java:97)
at org.glassfish.jersey.server.internal.inject.EntityParamValueParamProvider$EntityValueSupplier.apply(EntityParamValueParamProvider.java:80)
at org.glassfish.jersey.server.spi.internal.ParamValueFactoryWithSource.apply(ParamValueFactoryWithSource.java:74)
at org.glassfish.jersey.server.spi.internal.ParameterValueHelper.getParameterValues(ParameterValueHelper.java:92)
at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$AbstractMethodParamInvoker.getParamValues(JavaResourceMethodDispatcherProv

Answer 1

请增加tomcat connector setting(server.xml)的connectionTimeout。 https://tomcat.apache.org/tomcat-8.5-doc/config/http.html#Standard_Implementation

默认值为20000 ms(20s)。