java - Spring + JPA PermGen 内存不足

Question

编辑1:2014年5月28日

我尝试更改驱动程序(mysql-connector-java-5.1.30-bin 和 ojdbc7)。

在这两种情况下都会发生内存泄漏。例如(使用 Java VisualVM)使用 ojdbc 并查看我看到的最近的 GC:

oracle.djbc.driver.ClockSource$ThreadCachingBlockSource$BlockReleaser 不是从 contextClassLoader 中“免费”的

使用 Mysql 我有同样的问题(使用 sql 驱动程序)

原始帖子:只需配置 spring 和 jpa，重新启动应用程序 3/4 次后，我就会出现 PermGen 内存不足的情况。使用 Java VisualVM，我发现每次重新启动时我都会多一个类加载器(一开始我有 4 个类加载器，重新启动后我有 5 个类加载器，依此类推)。在我的 WEB-INB 中我有任何库。我设置的唯一类是这个(任何jsp和任何我执行逻辑的类，仅设置spring + jpa)。

我使用 Tomcat8 + Java 7 SDK:

引导配置

@SuppressWarnings("unused")
@Order(1)
public class FrameworkBootstrap implements WebApplicationInitializer
{

@Override
public void onStartup(ServletContext container)
        throws ServletException 
{
    container.getServletRegistration("default").addMapping("/resource/*");

    AnnotationConfigWebApplicationContext rootContext =
            new AnnotationConfigWebApplicationContext();
    rootContext.register(RootContextConfiguration.class);
    container.addListener(new ContextLoaderListener(rootContext));

    AnnotationConfigWebApplicationContext webContext =
            new AnnotationConfigWebApplicationContext();
    webContext.register(WebServletContextConfiguration.class);
    ServletRegistration.Dynamic dispatcher = container.addServlet(
            "springWebDispatcher", new DispatcherServlet(webContext)
    );
    dispatcher.setLoadOnStartup(1);
    dispatcher.addMapping("/");
}
}

Servlet 配置

@Configuration
@EnableWebMvc
@ComponentScan(
    basePackages = "it.dirimo.site",
    useDefaultFilters = false,
    includeFilters = @ComponentScan.Filter(WebController.class)
)
public class WebServletContextConfiguration extends WebMvcConfigurerAdapter
{
 @Inject ApplicationContext applicationContext;
 @Inject ObjectMapper objectMapper;
 @Inject Marshaller marshaller;
 @Inject Unmarshaller unmarshaller;
 @Inject SpringValidatorAdapter validator;

 @Override
    public void configureMessageConverters(
            List<HttpMessageConverter<?>> converters
    ) {
        converters.add(new ByteArrayHttpMessageConverter());
        converters.add(new StringHttpMessageConverter());
        converters.add(new FormHttpMessageConverter());
        converters.add(new SourceHttpMessageConverter<>());

        MarshallingHttpMessageConverter xmlConverter =
                new MarshallingHttpMessageConverter();
        xmlConverter.setSupportedMediaTypes(Arrays.asList(
                new MediaType("application", "xml"),
                new MediaType("text", "xml"),
                new MediaType("text", "json")
        ));
        xmlConverter.setMarshaller(this.marshaller);
        xmlConverter.setUnmarshaller(this.unmarshaller);
        converters.add(xmlConverter);

        MappingJackson2HttpMessageConverter jsonConverter =
                new MappingJackson2HttpMessageConverter();
        jsonConverter.setSupportedMediaTypes(Arrays.asList(
                new MediaType("application", "json"),
                new MediaType("text", "json")
        ));
        jsonConverter.setObjectMapper(this.objectMapper);
        converters.add(jsonConverter);
    }   

    @Override
    public void configureContentNegotiation(
            ContentNegotiationConfigurer configurer)
    {
        configurer.favorPathExtension(true).favorParameter(false)
                .parameterName("mediaType").ignoreAcceptHeader(false)
                .useJaf(false).defaultContentType(MediaType.APPLICATION_XML)
                .mediaType("xml", MediaType.APPLICATION_XML)
                .mediaType("json", MediaType.APPLICATION_JSON);
    }

    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> resolvers)
    {
        Sort defaultSort = new Sort(new Sort.Order(Sort.Direction.ASC, "id"));
        Pageable defaultPageable = new PageRequest(0, 10, defaultSort);

        SortHandlerMethodArgumentResolver sortResolver =
                new SortHandlerMethodArgumentResolver();
        sortResolver.setSortParameter("paging.sort");
        sortResolver.setFallbackSort(defaultSort);

        PageableHandlerMethodArgumentResolver pageableResolver =
                new PageableHandlerMethodArgumentResolver(sortResolver);
        pageableResolver.setMaxPageSize(100);
        pageableResolver.setOneIndexedParameters(true);
        pageableResolver.setPrefix("paging.");
        pageableResolver.setFallbackPageable(defaultPageable);

        resolvers.add(sortResolver);
        resolvers.add(pageableResolver);
    }

    @Override
    public void addFormatters(FormatterRegistry registry)
    {
        if(!(registry instanceof FormattingConversionService))
        {
            return;
        }

        DomainClassConverter<FormattingConversionService> converter =
                new DomainClassConverter<>((FormattingConversionService)registry);
        converter.setApplicationContext(this.applicationContext);
    }

    @Override
    public Validator getValidator()
    {
        return this.validator;
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry)
    {
        super.addInterceptors(registry);

        registry.addInterceptor(new LocaleChangeInterceptor());
    }

    @Bean
    public LocaleResolver localeResolver()
    {
        return new SessionLocaleResolver();
    }

    @Bean
    public ViewResolver viewResolver()
    {
        InternalResourceViewResolver resolver =
                new InternalResourceViewResolver();
        resolver.setViewClass(JstlView.class);
        resolver.setPrefix("/WEB-INF/jsp/view/");
        resolver.setSuffix(".jsp");
        return resolver;
    }

    @Bean
    public RequestToViewNameTranslator viewNameTranslator()
    {
        return new DefaultRequestToViewNameTranslator();
    }
}

根配置

@Configuration
@EnableScheduling
@EnableLoadTimeWeaving
@EnableAsync(
    mode = AdviceMode.PROXY, proxyTargetClass = true,
    order = 1
)
@EnableTransactionManagement(
    mode = AdviceMode.PROXY, proxyTargetClass = true,
    order = 2
)
@EnableJpaRepositories(
    basePackages = "it.dirimo.site.repositories",
    entityManagerFactoryRef = "entityManagerFactoryBean",
    transactionManagerRef = "jpaTransactionManager"
)
@ComponentScan(
    basePackages = "it.dirimo.site",
    excludeFilters =
    @ComponentScan.Filter({Controller.class, ControllerAdvice.class})
)
public class RootContextConfiguration implements AsyncConfigurer, SchedulingConfigurer
{
//private static final Logger log = LogManager.getLogger();

@Inject LoadTimeWeaver loadTimeWeaver;

@Bean
public MessageSource messageSource()
{
    ReloadableResourceBundleMessageSource messageSource =
            new ReloadableResourceBundleMessageSource();
    messageSource.setCacheSeconds(-1);
    messageSource.setDefaultEncoding(StandardCharsets.UTF_8.name());
    messageSource.setBasenames(
            "/WEB-INF/i18n/titles", "/WEB-INF/i18n/messages",
            "/WEB-INF/i18n/errors", "/WEB-INF/i18n/validation"
    );
    return messageSource;
}

@Bean
public LocalValidatorFactoryBean localValidatorFactoryBean()
{
    LocalValidatorFactoryBean validator = new LocalValidatorFactoryBean();
    validator.setValidationMessageSource(this.messageSource());
    return validator;
}

@Bean
public MethodValidationPostProcessor methodValidationPostProcessor()
{
    MethodValidationPostProcessor processor =
            new MethodValidationPostProcessor();
    processor.setValidator(this.localValidatorFactoryBean());
    return processor;
}

@Bean
public ObjectMapper objectMapper()
{
    ObjectMapper mapper = new ObjectMapper();
    mapper.findAndRegisterModules();
    mapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
    mapper.configure(DeserializationFeature.ADJUST_DATES_TO_CONTEXT_TIME_ZONE,
            false);
    return mapper;
}

@Bean
public Jaxb2Marshaller jaxb2Marshaller()
{
    Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
    marshaller.setPackagesToScan(new String[] { "it.dirimo.site" });
    return marshaller;
}

@Bean
public DataSource fileSearchDataSource()
{
    JndiDataSourceLookup lookup = new JndiDataSourceLookup();
    return lookup.getDataSource("jdbc/DIR");
}

@Bean
public LocalContainerEntityManagerFactoryBean entityManagerFactoryBean()
{
    Map<String, Object> properties = new Hashtable<>();
    properties.put("javax.persistence.schema-generation.database.action",
            "none");
    properties.put("hibernate.ejb.use_class_enhancer", "true");

    HibernateJpaVendorAdapter adapter = new HibernateJpaVendorAdapter();
    adapter.setDatabasePlatform("org.hibernate.dialect.Oracle10gDialect");

    LocalContainerEntityManagerFactoryBean factory =
            new LocalContainerEntityManagerFactoryBean();
    factory.setJpaVendorAdapter(adapter);
    factory.setDataSource(this.fileSearchDataSource());
    factory.setPackagesToScan("it.dirimo.site.entities");
    factory.setSharedCacheMode(SharedCacheMode.ENABLE_SELECTIVE);
    factory.setValidationMode(ValidationMode.NONE);
    factory.setLoadTimeWeaver(this.loadTimeWeaver);
    factory.setJpaPropertyMap(properties);
    return factory;
}

@Bean
public PlatformTransactionManager jpaTransactionManager()
{
    return new JpaTransactionManager(
            this.entityManagerFactoryBean().getObject()
    );
}

@Bean
public ThreadPoolTaskScheduler taskScheduler()
{
    ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler();
    scheduler.setPoolSize(20);
    scheduler.setThreadNamePrefix("task-");
    scheduler.setAwaitTerminationSeconds(60);
    scheduler.setWaitForTasksToCompleteOnShutdown(true);
    return scheduler;
}

@Override
public void configureTasks(ScheduledTaskRegistrar registrar) {
    TaskScheduler scheduler = this.taskScheduler();
    registrar.setTaskScheduler(scheduler);
}

@Override
public Executor getAsyncExecutor() {
    Executor executor = this.taskScheduler();
    return executor;
}
}

Answer 1

这是 Tomcat/Spring/Hibernate 的常见问题，通常没有适用于所有场景的明确答案。 最有可能的是，一般的潜在问题是每次重新部署时都会创建动态类，存储在 permgen 中，并且类定义永远不会被垃圾回收。这通常不是 Spring/Hibernate 的直接错误，而是而是 CGLIB 和/或 Tomcat 的类加载器处理的“功能”。

一些常见的建议:

• 将 -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled 添加到 tomcat 启动选项。

• 如果这是问题的原因，请远离 CGLIB。仅某些类型的代理需要 CGLIB。

• 将 JDBC jar 文件放在 {tomcat}/lib 中，而不是 WEB-INF/lib 中。

还有很多其他想法here和在互联网上，但一般来说，如果您无法解决上述问题，那么唯一的办法就是增加您的永久代并计划在每次重新部署后重新启动 tomcat。

有趣的是(根据我自己的经验)，这个问题对于最新的库/服务器/jdk 版本来说不是一个问题。