Redis + Caffeine打造超速两级缓存架构
背景
接口的逻辑非常简单:根据传入的城市、仓库和发货时间,查询快递的预计送达时间。
然而,由于会频繁调用这个接口,尤其是在大促期间,接口的性能要求极高。
数据量虽然不大,但为了确保接口的高性能和高可用性,决定采用 Redis + Caffeine 两级缓存策略,以应对可能出现的缓存雪崩、缓存穿透等问题。
本地缓存的优缺点
优点
- 极速查询:本地缓存基于内存,查询速度极快,适合数据更新频率低、实时性要求不高的场景(例如我们每天凌晨更新一次数据,总量约7k)。
- 减少网络I/O:相比查询远程缓存,本地缓存可以显著降低网络消耗,避免因网络问题导致的查询延迟。
缺点
- 一致性问题:在分布式环境下,本地缓存的更新难以同步到其他节点,容易导致数据不一致。
- 不支持持久化:Caffeine 缓存仅存储在内存中,一旦应用重启,缓存数据将丢失。
- 内存溢出风险:本地缓存需要合理设置容量,避免因数据过多导致内存溢出。
代码实现
一、配置类实现
1.MySQL表结构
CREATE TABLE `t_estimated_arrival_date` (`id` int(11) UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '主键id',`warehouse_id` varchar(32) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULLDEFAULTNULL COMMENT '货仓id',`warehouse` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULLDEFAULTNULL COMMENT '发货仓',`city` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULLDEFAULTNULL COMMENT '签收城市',`delivery_date` dateNULLDEFAULTNULL COMMENT '发货时间',`estimated_arrival_date` dateNULLDEFAULTNULL COMMENT '预计到货日期',
PRIMARY KEY (`id`) USING BTREE,
UNIQUE INDEX `uk_warehouse_id_city_delivery_date`(`warehouse_id`, `city`, `delivery_date`) USING BTREE
) ENGINE = InnoDB COMMENT ='预计到货时间表' ROW_FORMAT =Dynamic;
2.依赖配置(pom.xml)
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency><groupId>org.apache.commons</groupId><artifactId>commons-pool2</artifactId>
</dependency>
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency><groupId>com.github.ben-manes.caffeine</groupId><artifactId>caffeine</artifactId><version>2.9.2</version>
</dependency>
<dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.28</version>
</dependency>
<dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.3.1</version>
</dependency>
3.配置类
RedisConfig
public classRedisConfig {@Beanpublic RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory) {RedisTemplate<String, Object> redisTemplate = newRedisTemplate<>();redisTemplate.setConnectionFactory(connectionFactory);Jackson2JsonRedisSerializer<Object> serializer = newJackson2JsonRedisSerializer<>(Object.class);ObjectMappermapper=newObjectMapper();mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);mapper.activateDefaultTyping(LaissezFaireSubTypeValidator.instance, ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY);serializer.setObjectMapper(mapper);redisTemplate.setKeySerializer(newStringRedisSerializer());redisTemplate.setValueSerializer(serializer);redisTemplate.setHashKeySerializer(newStringRedisSerializer());redisTemplate.setHashValueSerializer(serializer);redisTemplate.afterPropertiesSet();return redisTemplate;}
}
CaffeineConfig
public classCaffeineConfig {@Beanpublic Cache<String, Object> caffeineCache() {return Caffeine.newBuilder().initialCapacity(128).maximumSize(1024).expireAfterWrite(60, TimeUnit.SECONDS).build();}@Beanpublic CacheManager cacheManager() {CaffeineCacheManagercacheManager=newCaffeineCacheManager();cacheManager.setCaffeine(Caffeine.newBuilder().initialCapacity(128).maximumSize(1024).expireAfterWrite(60, TimeUnit.SECONDS));return cacheManager;}
}
4.Service 实现
@Slf4j
@Service
public class DoubleCacheServiceImpl doubleCacheServiceImpl {@Resourceprivate Cache caffeineCache;@Resourceprivate RedisTemplate<String, Object> redisTemplate;@Resourceprivate EstimatedArrivalDateMapper estimatedArrivalDateMapper;@Overridepublic EstimatedArrivalDateEntity getEstimatedArrivalDateCommon(EstimatedArrivalDateEntity request) {String key = request.getDeliveryDate() + ":" + request.getWarehouseId() + ":" + request.getCity();log.info("Cache key: {}", key);Objectvalue = caffeineCache.getIfPresent(key);if (Objects.nonNull(value)) {log.info("get from caffeine");return EstimatedArrivalDateEntity.builder().estimatedArrivalDate(value.toString()).build();}value = redisTemplate.opsForValue().get(key);if (Objects.nonNull(value)) {log.info("get from redis");caffeineCache.put(key, value);return EstimatedArrivalDateEntity.builder().estimatedArrivalDate(value.toString()).build();}log.info("get from mysql");DateTimedeliveryDate = DateUtil.parse(request.getDeliveryDate(), "yyyy-MM-dd");EstimatedArrivalDateEntity entity = estimatedArrivalDateMapper.selectOne(newQueryWrapper<>().eq("delivery_date", deliveryDate).eq("warehouse_id", request.getWarehouseId()).eq("city", request.getCity()));redisTemplate.opsForValue().set(key, entity.getEstimatedArrivalDate(), 120, TimeUnit.SECONDS);caffeineCache.put(key, entity.getEstimatedArrivalDate());return EstimatedArrivalDateEntity.builder().estimatedArrivalDate(entity.getEstimatedArrivalDate()).build();}
}
代码分析:
- 首先从 Caffeine 缓存中获取数据,如果命中则直接返回。
- 如果 Caffeine 缓存未命中,则从 Redis 中查询数据,并将结果写入 Caffeine 缓存。
- 如果 Redis 中也未命中,则从数据库中查询数据,并同时写入 Redis 和 Caffeine 缓存。
二、注解实现
1.DoubleCache 注解
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DoubleCache {String cacheName();String[] key();longexpireTime() default 120;CacheType type() default CacheType.FULL;enumCacheType {FULL, PUT, DELETE}
}
2.DoubleCacheAspect
@Slf4j
@Component
@Aspect
public class DoubleCacheAspect {@Resourceprivate Cache caffeineCache;@Resourceprivate RedisTemplate<String, Object> redisTemplate;@Pointcut("@annotation(com.itender.redis.annotation.DoubleCache)")public void doubleCachePointcut() {}@Around("doubleCachePointcut()")public Object doAround(ProceedingJoinPoint point)throws Throwable {MethodSignature signature = (MethodSignature) point.getSignature();Methodmethod = signature.getMethod();String[] paramNames = signature.getParameterNames();Object[] args = point.getArgs();TreeMap<String, Object> treeMap = newTreeMap<>();for (int i = 0; i < paramNames.length; i++) {treeMap.put(paramNames[i], args[i]);}Double Cacheannotation = method.getAnnotation(DoubleCache.class);String elResult = DoubleCacheUtil.arrayParse(Lists.newArrayList(annotation.key()), treeMap);String realKey = annotation.cacheName() + ":" + elResult;if (annotation.type() == DoubleCache.CacheType.PUT) {Object object = point.proceed();redisTemplate.opsForValue().set(realKey, object, annotation.expireTime(), TimeUnit.SECONDS);caffeineCache.put(realKey, object);return object;} elseif (annotation.type() == DoubleCache.CacheType.DELETE) {redisTemplate.delete(realKey);caffeineCache.invalidate(realKey);return point.proceed();}Object caffeineCacheObj = caffeineCache.getIfPresent(realKey);if (Objects.nonNull(caffeineCacheObj)) {log.info("get data from caffeine");return caffeineCacheObj;}Object redisCache = redisTemplate.opsForValue().get(realKey);if (Objects.nonNull(redisCache)) {log.info("get data from redis");caffeineCache.put(realKey, redisCache);return redisCache;}log.info("get data from database");Object object = point.proceed();if (Objects.nonNull(object)) {log.info("get data from database write to cache: {}", object);redisTemplate.opsForValue().set(realKey, object, annotation.expireTime(), TimeUnit.SECONDS);caffeineCache.put(realKey, object);}return object;}
}
代码分析:
- 注解驱动:通过自定义注解 @DoubleCache,可以在方法上灵活配置缓存逻辑。
- 动态拼接 Key:支持使用 Spring EL 表达式动态拼接缓存 Key。
- 缓存一致性:在注解中支持全缓存、仅写入缓存、仅删除缓存等操作,便于灵活管理缓存数据。
总结
需要注意的是,本地缓存的容量和过期时间需要根据实际业务场景合理设置,以防止内存溢出等问题。
虽然 Redis 单独使用已经足够强大,但在某些场景下,结合 Caffeine 的本地缓存可以进一步提升性能。