The LocalResponseCacheGatewayFilterFactory is creating a new CacheManager for each Filter

[michael-wirth]

Describe the bug The LocalResponseCacheGatewayFilterFactory is not using the "gatewayCacheManger" bean, but always creating a new instance. Is this a bug or correct by design?

https://github.com/spring-cloud/spring-cloud-gateway/blob/eb098a759634f5e4898eb0963b83b966ae1b0063/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/factory/cache/LocalResponseCacheGatewayFilterFactory.java#L75

[ilozano2]

That's intentional. You have two types of Cache for LocalResponseCache

• Global: if you activate spring.cloud.gateway.global-filter.local-response-cache.enabled all the responses will be stored in the same cache unless you use LocalResponseCache filter at the route level
• At Route level: if you add the filter LocalResponseCache in a route, it will use its own independent cache with its own configuration

[michael-wirth]

I see the point of having an independent cache for each route, but why is it needed to instantiate a new cache-manager for each route?

If there are e.g. 5 routes with LocalResponseCache fiter then it will result in 5 cache-managers each having 1 cache. With that solution it is impossible to customize the cache manager.

[alimodares2003]

See here: https://github.com/spring-cloud/spring-cloud-gateway/blob/eb098a759634f5e4898eb0963b83b966ae1b0063/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/config/LocalResponseCacheAutoConfiguration.java#L49C8-L49C8

I think because proxyBeanMethods is set to false, each time creates a new cache-manager that its Bean is defined in line 71 of the LocalResponseCacheAutoConfiguration class

[michael-wirth]

I doubt that setting proxyBeanMethods to true would change anything because LocalResponseCacheAutoConfiguration.createGatewayCacheManager(cacheProperties) is not a @Bean method

[alimodares2003]

But it called in Bean method:

@Bean(name = RESPONSE_CACHE_MANAGER_NAME)
@Conditional(LocalResponseCacheAutoConfiguration.OnGlobalLocalResponseCacheCondition.class)
public CacheManager gatewayCacheManager(LocalResponseCacheProperties cacheProperties) {
    return createGatewayCacheManager(cacheProperties);
}

[michael-wirth]

That is what I'm saying.

The gatewayCacheManager Bean is NOT used in the LocalResponseCacheGatewayFilterFactory! Please check the code at https://github.com/spring-cloud/spring-cloud-gateway/blob/eb098a759634f5e4898eb0963b83b966ae1b0063/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/filter/factory/cache/LocalResponseCacheGatewayFilterFactory.java#L75

The cacheManager should be reused instead of creating a new instance for each route.

[alimodares2003]

Yes you're right, It's like anti-pattern!

[mohhmekk]

Same question from my side, why would you create a separate cache manager for each route. In my case, I need to create and use my own cache manager, according to the documentation I can by annotating my cache manager as primary but it is never being used.

A workaround that i have done is wrapping the filter inside another component and inject my cache manager myself:

@Component
class ResponseCacheFilterWrapper @Autowired constructor(responseCacheManager: ResponseCacheManager) : GlobalFilter, Ordered {
    val responseFilter: ResponseCacheGatewayFilter = ResponseCacheGatewayFilter(responseCacheManager)
    val log: Log = LogFactory.getLog(javaClass)

    override fun filter(exchange: ServerWebExchange?, chain: GatewayFilterChain?): Mono<Void> {
        log.info("Caching Response filter is active")
        return responseFilter.filter(exchange, chain)
    }

    override fun getOrder(): Int =
        responseFilter.order
}

The cache configuration looks like the following:

class CacheConfig {
    @Bean
    fun caffeineConfig(): Caffeine<Any, Any>? =
         Caffeine.newBuilder().expireAfterWrite(30, TimeUnit.MINUTES)

    @Bean
    @Primary
    fun cacheManager(caffeine: Caffeine<Any, Any>): CacheManager {
        val caffeineCacheManager = CaffeineCacheManager()
        caffeineCacheManager.setCaffeine(caffeine)
        return caffeineCacheManager
    }

    @Bean
    fun cacheName():String = "ALL-CACHES"

    @Bean
    fun responseCacheManager(cacheManager: CacheManager, cacheName: String): ResponseCacheManager =
        ResponseCacheManager(CacheKeyGenerator(), cacheManager.getCache(cacheName), Duration.ofMinutes(30))

}

[f-ranieri]

I am also facing this issue. Additionally, the cache managers created in LocalResponseCacheGatewayFilterFactory are not visible in '/actuator/caches.' As I wanted the option to manually invalidate some of these caches from time to time, I ended up with a custom re-implementation of LocalResponseCacheGatewayFilterFactory. I don't know if there was a better option to achieve this.

[spencergibb]

The properties are per cache manager. If you can describe how to do it without a cache manager per route, we'd be happy to work on it.

[spring-cloud-issues]

If you would like us to look at this issue, please provide the requested information. If the information is not provided within the next 7 days this issue will be closed.

[michael-wirth]

The properties could be set per cache not per cacheManager as it is possible with any other spring cache manager. I also don't understand why the implementation is bound to Caffeine and not using a generic solution and support any Cache implementation.

To instantiate a cache manager for each LocalResponseCacheGatewayFilterFactory is a code smell and I think it should be possible to share a cache manager and not instantiate a new one each time.

[spencergibb]

The properties could be set per cache not per cacheManager as it is possible with any other spring cache manager.

All the properties are set on Caffeine, not the cache manager. Can you show me how you would do it per cache?

https://github.com/spring-cloud/spring-cloud-gateway/blob/7e4bb5c185772021c8cb51a45543e7466cc0256c/spring-cloud-gateway-server/src/main/java/org/springframework/cloud/gateway/config/LocalResponseCacheAutoConfiguration.java#L95-L107

See #3145 for a more generic solution beyond caffeine.

[spencergibb]

After looking, it looks like registerCustomCache() would be the way to go?

[michael-wirth]

Thanks, I wasn't aware of this chsmge!