java - 为什么我的带有嵌入式 tomcat 的 Spring Boot 在处理第一个请求时速度太慢？

Question

环境

操作系统:macOS Mojave Version 10.14.5(centOS有同样问题)

Springboot:2.1.6.RELEASE(嵌入式tomcat 9.0.21),war

我是Spring Boot的新手，觉得对自己的项目搭建有帮助。现在我已经完成了我的工作，但是一个奇怪的现象困扰着我。我的项目花了大约 5 分钟来响应第一个请求，它花费了 5 分钟而不是 5 秒，第一次之后的请求似乎很正常。它非常慢，所以我需要你的帮助。

在 jstack 的帮助下，我了解到大部分时间都花在了下面的事情上，同样是在 unpack war 上。

"http-nio-15281-exec-5" #105 daemon prio=5 os_prio=31 tid=0x00007f988eaff800 nid=0x13b03 runnable [0x0000700013218000]
   java.lang.Thread.State: RUNNABLE
    at java.util.zip.Inflater.inflateBytes(Native Method)
    at java.util.zip.Inflater.inflate(Inflater.java:259)
    - locked <0x00000007bac79ab0> (a java.util.zip.ZStreamRef)
    at java.util.zip.InflaterInputStream.read(InflaterInputStream.java:152)
    at java.util.zip.ZipInputStream.read(ZipInputStream.java:194)
    at java.util.jar.JarInputStream.read(JarInputStream.java:207)
    at java.util.zip.ZipInputStream.closeEntry(ZipInputStream.java:140)
    at java.util.zip.ZipInputStream.getNextEntry(ZipInputStream.java:118)
    at java.util.jar.JarInputStream.getNextEntry(JarInputStream.java:142)
    at java.util.jar.JarInputStream.getNextJarEntry(JarInputStream.java:179)
    at org.apache.catalina.webresources.JarWarResourceSet.getArchiveEntries(JarWarResourceSet.java:117)
    - locked <0x00000007810e7770> (a java.lang.Object)
    at org.apache.catalina.webresources.AbstractArchiveResourceSet.getResource(AbstractArchiveResourceSet.java:253)
    at org.apache.catalina.webresources.StandardRoot.getResourceInternal(StandardRoot.java:282)
    at org.apache.catalina.webresources.Cache.getResource(Cache.java:62)
    at org.apache.catalina.webresources.StandardRoot.getResource(StandardRoot.java:217)
    at org.apache.catalina.webresources.StandardRoot.getClassLoaderResource(StandardRoot.java:226)
    at org.apache.catalina.loader.WebappClassLoaderBase.findClassInternal(WebappClassLoaderBase.java:2303)
    at org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:865)
    at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.findClassIgnoringNotFound(TomcatEmbeddedWebappClassLoader.java:119)
    at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.doLoadClass(TomcatEmbeddedWebappClassLoader.java:84)
    at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.loadClass(TomcatEmbeddedWebappClassLoader.java:66)
    - locked <0x00000007af22a990> (a java.lang.Object)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1188)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at com.sun.beans.finder.ClassFinder.findClass(ClassFinder.java:67)
    at com.sun.beans.finder.ClassFinder.findClass(ClassFinder.java:110)
    at java.beans.Introspector.findCustomizerClass(Introspector.java:1301)
    at java.beans.Introspector.getTargetBeanDescriptor(Introspector.java:1295)
    at java.beans.Introspector.getBeanInfo(Introspector.java:425)
    at java.beans.Introspector.getBeanInfo(Introspector.java:262)
    at java.beans.Introspector.getBeanInfo(Introspector.java:204)
    at org.springframework.beans.CachedIntrospectionResults.getBeanInfo(CachedIntrospectionResults.java:248)
    at org.springframework.beans.CachedIntrospectionResults.<init>(CachedIntrospectionResults.java:273)
    at org.springframework.beans.CachedIntrospectionResults.forClass(CachedIntrospectionResults.java:177)
    at org.springframework.beans.BeanWrapperImpl.getCachedIntrospectionResults(BeanWrapperImpl.java:174)
    at org.springframework.beans.BeanWrapperImpl.getLocalPropertyHandler(BeanWrapperImpl.java:230)
    at org.springframework.beans.BeanWrapperImpl.getLocalPropertyHandler(BeanWrapperImpl.java:63)
    at org.springframework.beans.AbstractNestablePropertyAccessor.getPropertyValue(AbstractNestablePropertyAccessor.java:620)
    at org.springframework.beans.AbstractNestablePropertyAccessor.getPropertyValue(AbstractNestablePropertyAccessor.java:612)
    at org.springframework.data.util.DirectFieldAccessFallbackBeanWrapper.getPropertyValue(DirectFieldAccessFallbackBeanWrapper.java:52)
    at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.getId(JpaMetamodelEntityInformation.java:154)
    at org.springframework.data.repository.core.support.AbstractEntityInformation.isNew(AbstractEntityInformation.java:42)
    at org.springframework.data.jpa.repository.support.JpaMetamodelEntityInformation.isNew(JpaMetamodelEntityInformation.java:233)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.save(SimpleJpaRepository.java:506)
    at org.springframework.data.jpa.repository.support.SimpleJpaRepository.saveAndFlush(SimpleJpaRepository.java:521)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.data.repository.core.support.RepositoryComposition$RepositoryFragments.invoke(RepositoryComposition.java:359)
    at org.springframework.data.repository.core.support.RepositoryComposition.invoke(RepositoryComposition.java:200)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$ImplementationMethodExecutionInterceptor.invoke(RepositoryFactorySupport.java:644)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:608)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$invoke$3(RepositoryFactorySupport.java:595)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor$$Lambda$641/1539038539.get(Unknown Source)
    at org.springframework.data.repository.util.QueryExecutionConverters$$Lambda$640/28145535.apply(Unknown Source)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:595)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.transaction.interceptor.TransactionInterceptor$$Lambda$636/1377160602.proceedWithInvocation(Unknown Source)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:295)
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.dao.support.PersistenceExceptionTranslationInterceptor.invoke(PersistenceExceptionTranslationInterceptor.java:139)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.jpa.repository.support.CrudMethodMetadataPostProcessor$CrudMethodMetadataPopulatingMethodInterceptor.invoke(CrudMethodMetadataPostProcessor.java:138)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
    at com.sun.proxy.$Proxy125.saveAndFlush(Unknown Source)

Answer 1

我们遇到了完全相同的问题，我花了好几天时间解决这个问题，但通过这个配置部分设法解决了它:

@Configuration
public class EmbeddedTomcatConfiguration {

  @Bean
  TomcatServletWebServerFactory tomcatFactory() {
    return new TomcatServletWebServerFactory() {

      @Override
      protected void postProcessContext(Context context) {
        context.setResources(new ExtractingRoot());
      }
    };
  }

  @Bean
  public WebServerFactoryCustomizer<TomcatServletWebServerFactory> servletContainerCustomizer() {
    return new WebServerFactoryCustomizer<TomcatServletWebServerFactory>() {

      @Override
      public void customize(TomcatServletWebServerFactory container) {
        container.addContextCustomizers(
            new TomcatContextCustomizer() {
              @Override
              public void customize(Context cntxt) {
                cntxt.setReloadable(false);
              }
            });
      }
    };
  }
}

这基本上做了两件事...

1. 它要求 Tomcat 不要丢弃加载的类并进行刷新。
2. 它告诉 Tomcat 在启动时提取包(这需要更多的磁盘空间)而不是扫描未提取的包。