Enforce static handler inmem cache

config.go

@@ -34,8 +34,9 @@ type ServerConfig struct {
 }
 
 type CacheConfig struct {
-	Enabled bool         `toml:"enabled"`
-	TTL     TOMLDuration `toml:"ttl"`
+	Enabled       bool         `toml:"enabled"`
+	UseInmemCache bool         `toml:"use_inmem_cache"`
+	TTL           TOMLDuration `toml:"ttl"`
 }
 
 type RedisConfig struct {

frontend_rate_limiter.go

@@ -109,6 +109,8 @@ func NewRedisFrontendRateLimiter(r redis.UniversalClient, dur time.Duration, max
 }
 
 func (r *RedisFrontendRateLimiter) Take(ctx context.Context, key string) (bool, error) {
+	start := time.Now()
+
 	var incr *redis.IntCmd
 	truncTS := truncateNow(r.dur)
 	fullKey := fmt.Sprintf("rate_limit:%s:%s:%d", r.prefix, key, truncTS)
@@ -122,6 +124,8 @@ func (r *RedisFrontendRateLimiter) Take(ctx context.Context, key string) (bool,
 		return false, err
 	}
 
+	redisFrontendRateLimiterCacheDurationSumm.WithLabelValues("TAKE").Observe(float64(time.Since(start).Milliseconds()))
+
 	return incr.Val()-1 < int64(r.max), nil
 }
 

metrics.go

@@ -235,6 +235,13 @@ var (
 		Buckets:   MillisecondDurationBuckets,
 	}, []string{"command"})
 
+	redisFrontendRateLimiterCacheDurationSumm = promauto.NewHistogramVec(prometheus.HistogramOpts{
+		Namespace: MetricsNamespace,
+		Name:      "redis_frontend_rate_limiter_cache_duration_milliseconds",
+		Help:      "Histogram of Redis Frontend Rate limiter durations, in milliseconds.",
+		Buckets:   MillisecondDurationBuckets,
+	}, []string{"command"})
+
 	tooManyRequestErrorsTotal = promauto.NewCounterVec(prometheus.CounterOpts{
 		Namespace: MetricsNamespace,
 		Name:      "too_many_request_errors_total",

proxyd.go

@@ -357,18 +357,23 @@ func Start(config *Config) (*Server, func(), error) {
 		rpcCache RPCCache
 	)
 	if config.Cache.Enabled {
-		if redisClient == nil {
-			log.Warn("redis is not configured, using in-memory cache")
+		if config.Cache.UseInmemCache {
+			// enforce inmem cache for staticHandler methods
 			cache = newMemoryCache()
 		} else {
-			ttl := defaultCacheTtl
-			if config.Cache.TTL != 0 {
-				ttl = time.Duration(config.Cache.TTL)
-			}
-			cache = newRedisCache(redisClient, redisReadClient, config.Redis.Namespace, ttl)
+			if redisClient == nil {
+				log.Warn("redis is not configured, using in-memory cache")
+				cache = newMemoryCache()
+			} else {
+				ttl := defaultCacheTtl
+				if config.Cache.TTL != 0 {
+					ttl = time.Duration(config.Cache.TTL)
+				}
+				cache = newRedisCache(redisClient, redisReadClient, config.Redis.Namespace, ttl)
 
-			if config.Redis.FallbackToMemory {
-				cache = newFallbackCache(cache, newMemoryCache())
+				if config.Redis.FallbackToMemory {
+					cache = newFallbackCache(cache, newMemoryCache())
+				}
 			}
 		}
 		rpcCache = newRPCCache(newCacheWithCompression(cache))