Spring Redis错误句柄

Question

我在新项目中使用Spring + Redis作为缓存组件。 spring config xml文件是：

<!-- 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" />

用法是

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

我的测试用例是：

@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服务器正在运行，则代码正在正常运行。但我的问题是，如果我关闭Redis服务器，它将抛出异常：

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

我想询问客户端是否无法连接Redis Server，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（可能是崩溃或网络未启动），它应该直接连接到数据库并获取数据。

Answer 1

我遇到了同样的问题。我正在开发一些针对数据库的数据服务，通过Spring Caching注释将Redis用作缓存存储。如果Redis服务器不可用，我希望服务继续像未缓存一样运行，而不是抛出异常。

首先，我尝试了一个自定义的CacheErrorHandler，这是Spring提供的一种机制。它没有用，因为它只处理RuntimeExceptions，但仍然让像java.net.ConnectException这样的东西搞砸了。

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。这看起来有点像黑客，我可能已经覆盖了太少的execute（）方法或太多，但它在我的所有测试用例中都像魅力一样。

但这种方法有一个重要的操作方面。如果Redis服务器不可用，则必须先将其刷新（清除条目），然后再将其提供。否则，由于同时发生的更新，您可能会开始检索包含错误数据的缓存条目。

以下是来源。随意使用它。我希望它有所帮助。

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。我设法通过添加两件事来解决它：

• connectionFactory的超时
• 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());
        }
    }
}

Answer 3

我使用LettuceConnectionFactory添加了Spring boot v2的答案

@Configuration
@EnableCaching
public class RedisCacheConfig extends CachingConfigurerSupport implements CachingConfigurer {

    @Value("${redis.hostname:localhost}")
    private String redisHost;

    @Value("${redis.port:6379}")
    private int redisPort;

    @Value("${redis.timeout.secs:1}")
    private int redisTimeoutInSecs;

    @Value("${redis.socket.timeout.secs:1}")
    private int redisSocketTimeoutInSecs;

    @Value("${redis.ttl.hours:1}")
    private int redisDataTTL;

    // @Autowired
    // private ObjectMapper objectMapper;

    @Bean
    public LettuceConnectionFactory redisConnectionFactory() {
        // LettuceClientConfiguration clientConfig = LettuceClientConfiguration.builder()
        // .commandTimeout(Duration.ofSeconds(redisConnectionTimeoutInSecs)).shutdownTimeout(Duration.ZERO).build();
        //
        // return new LettuceConnectionFactory(new RedisStandaloneConfiguration(redisHost, redisPort), clientConfig);

        final SocketOptions socketOptions = SocketOptions.builder().connectTimeout(Duration.ofSeconds(redisSocketTimeoutInSecs)).build();

        final ClientOptions clientOptions = ClientOptions.builder().socketOptions(socketOptions).build();

        LettuceClientConfiguration clientConfig = LettuceClientConfiguration.builder()
                .commandTimeout(Duration.ofSeconds(redisTimeoutInSecs)).clientOptions(clientOptions).build();
        RedisStandaloneConfiguration serverConfig = new RedisStandaloneConfiguration(redisHost, redisPort);

        final LettuceConnectionFactory lettuceConnectionFactory = new LettuceConnectionFactory(serverConfig, clientConfig);
        lettuceConnectionFactory.setValidateConnection(true);
        return lettuceConnectionFactory;

    }

    @Bean
    public RedisTemplate<Object, Object> redisTemplate() {
        RedisTemplate<Object, Object> redisTemplate = new RedisTemplate<Object, Object>();
        redisTemplate.setConnectionFactory(redisConnectionFactory());
        return redisTemplate;
    }

    @Bean
    public RedisCacheManager redisCacheManager(LettuceConnectionFactory lettuceConnectionFactory) {

        /**
         * If we want to use JSON Serialized with own object mapper then use the below config snippet
         */
        // RedisCacheConfiguration redisCacheConfiguration =
        // RedisCacheConfiguration.defaultCacheConfig().disableCachingNullValues()
        // .entryTtl(Duration.ofHours(redisDataTTL)).serializeValuesWith(RedisSerializationContext.SerializationPair
        // .fromSerializer(new GenericJackson2JsonRedisSerializer(objectMapper)));

        RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig().disableCachingNullValues()
                .entryTtl(Duration.ofHours(redisDataTTL))
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(RedisSerializer.java()));

        redisCacheConfiguration.usePrefix();

        RedisCacheManager redisCacheManager = RedisCacheManager.RedisCacheManagerBuilder.fromConnectionFactory(lettuceConnectionFactory)
                .cacheDefaults(redisCacheConfiguration).build();

        redisCacheManager.setTransactionAware(true);
        return redisCacheManager;
    }


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

RedisCacheErrorHandler.java在下面给出

public class RedisCacheErrorHandler implements CacheErrorHandler {

    private static final Logger log = LoggerFactory.getLogger(RedisCacheErrorHandler.class);

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

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

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

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

    /**
     * We handle redis connection timeout exception , if the exception is handled then it is treated as a cache miss and
     * gets the data from actual storage
     * 
     * @param exception
     */
    private void handleTimeOutException(RuntimeException exception) {

        if (exception instanceof RedisCommandTimeoutException)
            return;
    }
}

Answer 4

不需要LettuceConnectionFactory。仅使用自定义CacheConfig即可扩展CachingConfigurerSupport。并覆盖errorHandler（）方法。

您只需要实现自定义CacheErrorHandler，就像@Tan mally在他的回答中所做的那样。

Answer 5

您可以按照其他答案中的建议使用 CacheErrorHandler。但你应该确保 RedisCacheManager transactionAware 到 false 在您的 Redis 缓存配置中（以确保在执行缓存部分时尽早提交事务并且错误被 CacheErrorHandler 捕获并且不要等到结束跳过 CacheErrorHandler 部分的执行）。将 transactionAware 设置为 false 的函数如下所示：

    @Bean
    public RedisCacheManager redisCacheManager(LettuceConnectionFactory lettuceConnectionFactory) {
        JdkSerializationRedisSerializer redisSerializer = new JdkSerializationRedisSerializer(getClass().getClassLoader());

        RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofHours(redisDataTTL))
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer));

        redisCacheConfiguration.usePrefix();

        RedisCacheManager redisCacheManager = RedisCacheManager.RedisCacheManagerBuilder.fromConnectionFactory(lettuceConnectionFactory)
                .cacheDefaults(redisCacheConfiguration)
                .build();

        redisCacheManager.setTransactionAware(false);
        return redisCacheManager;
    }