java - Spring-boot中使用缓存抽象的缓存故障转移机制

Question

我正在我的代码中处理 spring-data-redis 和缓存抽象。我在缓存抽象中使用了 redis 作为缓存服务器。每当我为数据访问 JPARepository 时，缓存抽象都会有所帮助。它执行第一次从数据库中获取数据的方法，并从第二次开始从缓存中获取数据。

我的主要查询是:
有没有一种方法可以让缓存抽象识别缓存服务器未启动，所以它应该再次执行该方法以从数据库中获取数据，而不是在尝试从缓存中获取数据时卡住。

代码如下:

用于配置缓存:

@Configuration
@EnableCaching
public class CacheConfig {

@Autowired
private ApplicationContext applicationContext;

/*  below code is specific to redis implementation */



        @Bean
        public RedisConnectionFactory redisConnectionFactory(@Value("${redis.host}") String redisHost,
        @Value("${redis.port}") Integer redisPort) {
            JedisConnectionFactory cf = new JedisConnectionFactory();
            cf.setHostName(redisHost);
            cf.setPort(redisPort);
            return cf;
        }

        @Bean(name="redisTemplate")
        RedisTemplate redisTemplate() 
        {
            final RedisTemplate template =  new RedisTemplate();
            template.setConnectionFactory(applicationContext.getBean(RedisConnectionFactory.class));
            return template;
        }

        @Bean
        public CacheManager cacheManager() {
            RedisCacheManager redisCacheManager = new RedisCacheManager((RedisTemplate) applicationContext.getBean("redisTemplate"));
            redisCacheManager.setTransactionAware(true);
            redisCacheManager.setUsePrefix(true);
            return redisCacheManager;
        }

我使用缓存的代码:

@Override
@Cacheable(value = IC_CACHE, key = "#id")
public IssueCategory getIssueCategoriesById(Integer id) {
    return issueCategoriesRepo.findById(id);
}

现在假设redis 从后面停止工作或关闭。它给出以下异常:

java.net.ConnectException: Connection refused
	at java.net.PlainSocketImpl.socketConnect(Native Method)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:345)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
	at java.net.Socket.connect(Socket.java:589)
	at redis.clients.jedis.Connection.connect(Connection.java:144)
	at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:71)
	at redis.clients.jedis.BinaryJedis.connect(BinaryJedis.java:1783)
	at redis.clients.jedis.JedisFactory.makeObject(JedisFactory.java:65)
	at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:836)
	at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:434)
	at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:361)
	at redis.clients.util.Pool.getResource(Pool.java:40)
	at redis.clients.jedis.JedisPool.getResource(JedisPool.java:84)
	at redis.clients.jedis.JedisPool.getResource(JedisPool.java:10)
	at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.fetchJedisConnector(JedisConnectionFactory.java:133)
	at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.getConnection(JedisConnectionFactory.java:229)
	at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.getConnection(JedisConnectionFactory.java:57)
	at org.springframework.data.redis.core.RedisConnectionUtils.doGetConnection(RedisConnectionUtils.java:128)
	at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:91)
	at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:78)
	at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:177)
	at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:152)
	at org.springframework.data.redis.cache.RedisCache.get(RedisCache.java:88)
	at org.springframework.cache.transaction.TransactionAwareCacheDecorator.get(TransactionAwareCacheDecorator.java:66)
	at org.springframework.cache.interceptor.AbstractCacheInvoker.doGet(AbstractCacheInvoker.java:68)
	at org.springframework.cache.interceptor.CacheAspectSupport.findInCaches(CacheAspectSupport.java:461)
	at org.springframework.cache.interceptor.CacheAspectSupport.findCachedItem(CacheAspectSupport.java:432)
	at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:333)
	at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:299)
	at org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:61)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207)
	at com.sun.proxy.$Proxy113.getIssueCategoriesById(Unknown Source)
	at com.somexyz.somemodule.service.impl.RulesEngineServiceImpl.getApplicableNodes(RulesEngineServiceImpl.java:94)
	at com.somexyz.somemodule.web.api.somemoduleAPIController.getApplicableNodes(somemoduleAPIController.java:35)
	at com.somexyz.somemodule.web.api.somemoduleAPIController$$FastClassBySpringCGLIB$$1dabf625.invoke(<generated>)
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
	at com.somexyz.somemodule.web.config.ResponseTimeInterceptor.invokeUnderTrace(ResponseTimeInterceptor.java:23)
	at org.springframework.aop.interceptor.AbstractTraceInterceptor.invoke(AbstractTraceInterceptor.java:112)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)
	at com.somexyz.somemodule.web.api.somemoduleAPIController$$EnhancerBySpringCGLIB$$c8dbe185.getApplicableNodes(<generated>)
	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:497)
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:644)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.springframework.boot.actuate.autoconfigure.EndpointWebMvcAutoConfiguration$ApplicationContextHeaderFilter.doFilterInternal(EndpointWebMvcAutoConfiguration.java:291)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:199)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118)
	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:154)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:199)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:199)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:110)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:57)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:50)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192)
	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at com.somexyz.somemodule.web.config.somemoduleRequestMetricsFilter.doFilter(somemoduleRequestMetricsFilter.java:33)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:102)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:85)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.springframework.boot.actuate.autoconfigure.MetricFilterAutoConfiguration$MetricsFilter.doFilterInternal(MetricFilterAutoConfiguration.java:90)
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:516)
	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1086)
	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:659)
	at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1558)
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1515)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
	at java.lang.Thread.run(Thread.java:745)

有没有办法处理它，使系统不会出现故障。请指教。

Answer 1

从 Spring Boot 1.2(Spring Framework 4.1 及更高版本)开始，缓存抽象提供了一个可以实现以处理这些错误的策略接口(interface):CacheErrorHandler

您的 CacheConfig 应该从 CachingConfigurerSupport 扩展并覆盖 errorHandler() 方法(检查 Javadoc)。