Spring Redis错误处理

Question

我在新项目中使用Spring + Redis作为缓存组件。 Spring配置XML文件：

<!-- Jedis Connection --> 
<bean id="jedisConnectionFactory" 
    class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory" 
    p:host-name="${redis.ip}" p:port="${redis.port}" p:use-pool="${redis.use-pool}" /> 

<!-- Redis Template --> 
<bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate"> 
    <property name="connectionFactory" ref="jedisConnectionFactory" /> 
    <property name="keySerializer"> 
     <bean class="org.springframework.data.redis.serializer.StringRedisSerializer" /> 
    </property> 
    <property name="valueSerializer"> 
     <bean class="org.springframework.data.redis.serializer.JdkSerializationRedisSerializer" /> 
    </property> 
</bean> 

<bean id="cacheManager" class="org.springframework.data.redis.cache.RedisCacheManager" c:template-ref="redisTemplate"/> 

<cache:annotation-driven mode="proxy" proxy-target-class="true" cache-manager="cacheManager" /> 

用法

@Cacheable(value = "cacheManager", key="#userId") 
public User getUser(String userId) { 
    System.out.println("execute=="); 
    return userAdminMapper.getUser(userId); 
} 

我的测试情况是：

@Test 
public void testCacheUser2() { 
    String id = "test"; 
    User user = userService.getUser(id); 
    System.out.println(user); 
    user.setUserCreateDate(new Date()); 
    userService.updateUser(user); 
    User user2 = userService.getUser(id); 
    System.out.println(user2); 
    User user3 = userService.getUser(id); 
    System.out.println(user3); 
} 

如果Redis的服务器正在运行，代码运行正常。但我的问题是，如果我关机Redis的服务器，它会抛出异常：

org.springframework.data.redis.RedisConnectionFailureException: Cannot get Jedis connection; nested exception is redis.clients.jedis.exceptions.JedisConnectionException: java.net.ConnectException: Connection refused: connect 
    at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.fetchJedisConnector(JedisConnectionFactory.java:140) 
    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:87) 
    at org.springframework.cache.interceptor.CacheAspectSupport.findInCaches(CacheAspectSupport.java:297) 
    at org.springframework.cache.interceptor.CacheAspectSupport.findInAnyCaches(CacheAspectSupport.java:287) 
    at org.springframework.cache.interceptor.CacheAspectSupport.collectPutRequests(CacheAspectSupport.java:266) 
    at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:199) 
    at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:178) 
    at org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:60) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 
    at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98) 
    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262) 
    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95) 
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) 
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:644) 
    at sg.infolab.common.admin.service.impl.UserServiceImpl$$EnhancerBySpringCGLIB$$c7f982a7.getUser(<generated>) 
    at sg.infolab.admin.test.RedisServiceTest.testCacheUser2(RedisServiceTest.java:35) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) 
    at java.lang.reflect.Method.invoke(Method.java:597) 
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) 
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) 
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) 
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) 
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74) 
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:83) 
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72) 
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:232) 
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:89) 
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) 
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) 
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) 
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) 
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) 
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) 
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71) 
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309) 
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:175) 
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) 
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197) 
Caused by: redis.clients.jedis.exceptions.JedisConnectionException: java.net.ConnectException: Connection refused: connect 
    at redis.clients.jedis.Connection.connect(Connection.java:150) 
    at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:71) 
    at redis.clients.jedis.BinaryJedis.connect(BinaryJedis.java:1783) 
    at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.fetchJedisConnector(JedisConnectionFactory.java:137) 
    ... 50 more 
Caused by: java.net.ConnectException: Connection refused: connect 
    at java.net.PlainSocketImpl.socketConnect(Native Method) 
    at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351) 
    at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213) 
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200) 
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366) 
    at java.net.Socket.connect(Socket.java:529) 
    at redis.clients.jedis.Connection.connect(Connection.java:144) 
    ... 53 more 

我要问，如果客户端无法连接服务器的Redis，它为什么会抛出异常？我们可以像这样配置场景 - 如果缓存层（Redis Server）无法连接（可能崩溃或网络不通），它应该直接连接到数据库并获取数据。

Answer 1

我有同样的问题。我正在开发一些针对数据库的数据服务，通过Spring缓存注释将Redis用作缓存存储。如果Redis服务器变得不可用，我希望这些服务继续像未缓存一样运行，而不是抛出异常。

起初，我尝试了一个自定义的CacheErrorHandler，一个由Spring提供的机制。它并不完美，因为它只处理RuntimeExceptions，并且仍然允许诸如java.net.ConnectException之类的东西吹起来。

最后我做的是扩展RedisTemplate，覆盖一些execute（）方法，以便它们记录警告而不是传播异常。这似乎有点破解，我可能会覆盖太少的execute（）方法或太多，但它在我的所有测试用例中都像一个魅力。但是，这种方法有一个重要的操作方面。如果Redis服务器变得不可用，您必须刷新它（清除条目），然后再次使用它。否则，您有可能开始检索由于同时发生的更新而导致数据不正确的缓存条目。

以下是来源。随意使用它。我希望它有帮助。

import java.util.List; 

import org.slf4j.Logger; 
import org.slf4j.LoggerFactory; 
import org.springframework.data.redis.core.RedisCallback; 
import org.springframework.data.redis.core.RedisTemplate; 
import org.springframework.data.redis.core.SessionCallback; 
import org.springframework.data.redis.core.script.RedisScript; 
import org.springframework.data.redis.serializer.RedisSerializer; 


/** 
* An extension of RedisTemplate that logs exceptions instead of letting them propagate. 
* If the Redis server is unavailable, cache operations are always a "miss" and data is fetched from the database. 
*/ 
public class LoggingRedisTemplate<K, V> extends RedisTemplate<K, V> { 

    private static final Logger logger = LoggerFactory.getLogger(LoggingRedisTemplate.class); 


    @Override 
    public <T> T execute(final RedisCallback<T> action, final boolean exposeConnection, final boolean pipeline) { 
     try { 
      return super.execute(action, exposeConnection, pipeline); 
     } 
     catch(final Throwable t) { 
      logger.warn("Error executing cache operation: {}", t.getMessage()); 
      return null; 
     } 
    } 


    @Override 
    public <T> T execute(final RedisScript<T> script, final List<K> keys, final Object... args) { 
     try { 
      return super.execute(script, keys, args); 
     } 
     catch(final Throwable t) { 
      logger.warn("Error executing cache operation: {}", t.getMessage()); 
      return null; 
     } 
    } 


    @Override 
    public <T> T execute(final RedisScript<T> script, final RedisSerializer<?> argsSerializer, final RedisSerializer<T> resultSerializer, final List<K> keys, final Object... args) { 
     try { 
      return super.execute(script, argsSerializer, resultSerializer, keys, args); 
     } 
     catch(final Throwable t) { 
      logger.warn("Error executing cache operation: {}", t.getMessage()); 
      return null; 
     } 
    } 


    @Override 
    public <T> T execute(final SessionCallback<T> session) { 
     try { 
      return super.execute(session); 
     } 
     catch(final Throwable t) { 
      logger.warn("Error executing cache operation: {}", t.getMessage()); 
      return null; 
     } 
    } 
} 

Answer 2

我有同样的错误。我设法通过将两件事情来解决这个问题：

• 超时connectionFactory的
• 错误处理程序

@Configuration 
@ConditionalOnProperty(name = "redis.enabled", havingValue = "true") 
@EnableCaching 
public class RedisCacheConfig extends CachingConfigurerSupport implements CachingConfigurer { 

    @Value("${redis.host}") 
    private String host; 

    @Value("${redis.port}") 
    private Integer port; 

    @Value("${redis.expiration.timeout}") 
    private Integer expirationTimeout; 

    @Bean 
    public JedisConnectionFactory redisConnectionFactory() { 
     JedisConnectionFactory redisConnectionFactory = new JedisConnectionFactory(); 
     redisConnectionFactory.setHostName(host); 
     redisConnectionFactory.setPort(port); 
     redisConnectionFactory.setTimeout(10); 
     return redisConnectionFactory; 
    } 

    @Bean 
    public RedisTemplate<String, Set<String>> redisTemplate(@Autowired RedisConnectionFactory redisConnectionFactory) { 
     RedisTemplate<String, Set<String>> redisTemplate = new RedisTemplate<>(); 
     redisTemplate.setConnectionFactory(redisConnectionFactory); 
     return redisTemplate; 
    } 

    @Bean 
    public CacheManager cacheManager(@Autowired RedisTemplate redisTemplate) { 
     RedisCacheManager cacheManager = new RedisCacheManager(redisTemplate); 
     cacheManager.setDefaultExpiration(expirationTimeout); 
     return cacheManager; 
    } 

    @Override 
    public CacheErrorHandler errorHandler() { 
     return new RedisCacheErrorHandler(); 
    } 

    @Slf4j 
    public static class RedisCacheErrorHandler implements CacheErrorHandler { 

     @Override 
     public void handleCacheGetError(RuntimeException exception, Cache cache, Object key) { 
      log.info("Unable to get from cache " + cache.getName() + " : " + exception.getMessage()); 
     } 

     @Override 
     public void handleCachePutError(RuntimeException exception, Cache cache, Object key, Object value) { 
      log.info("Unable to put into cache " + cache.getName() + " : " + exception.getMessage()); 
     } 

     @Override 
     public void handleCacheEvictError(RuntimeException exception, Cache cache, Object key) { 
      log.info("Unable to evict from cache " + cache.getName() + " : " + exception.getMessage()); 
     } 

     @Override 
     public void handleCacheClearError(RuntimeException exception, Cache cache) { 
      log.info("Unable to clean cache " + cache.getName() + " : " + exception.getMessage()); 
     } 
    } 
}