flush out race conditions

Author: donchev7

cmd/cache-offloader.go

@@ -21,7 +21,7 @@ func getInMemoryStorage(cfg config.Config) http.Cacher {
 	case "lru":
 		return storage.NewLRUCache(cfg.CacheConfig.Size, cfg.CacheConfig.StaleInSeconds)
 	case "lfu":
-		storage.NewLFUCache(cfg.CacheConfig.Size, cfg.CacheConfig.StaleInSeconds)
+		return storage.NewLFUCache(cfg.CacheConfig.Size, cfg.CacheConfig.StaleInSeconds)
 	default:
 		log.Error().Msgf("Unknown cache strategy: %s", cfg.CacheConfig.Strategy)
 		log.Fatal().Msg("Supported cache strategies are LRU and LFU")

dev.env

@@ -1,14 +1,14 @@
 # ServerConfig
 SERVER_PORT=8000
-SERVER_LOG_LEVEL=DEBUG
+SERVER_LOG_LEVEL=ERROR
 SERVER_STORAGE=memory
 DOWNSTREAM_HOST=http://httpbin.org
 SHUTDOWN_GRACE_PERIOD=30
 
 # CacheConfig
 CACHE_SHOULD_HASH_QUERY="true"
 CACHE_HASH_QUERY_IGNORE=utm,live
-CACHE_STRATEGY=LRU
+CACHE_STRATEGY=LFU
 CACHE_SIZE_MB=10
 CACHE_STALE_WHILE_REVALIDATE_SEC=60
 CACHE_IGNORE_ENDPOINTS=/status,/health

pkg/storage/memory-lfu.go

@@ -103,8 +103,8 @@ func (lfu *LFUCache) LookUp(ctx context.Context, key string) (*model.Response, e
 	proc := make(chan *model.Response, 1)
 
 	go func() {
-		lfu.mtx.RLock()
-		defer lfu.mtx.RUnlock()
+		lfu.mtx.Lock()
+		defer lfu.mtx.Unlock()
 
 		if val, found := lfu.cache[key]; found {
 			lfu.update(val)
@@ -136,6 +136,9 @@ func (lfu *LFUCache) LookUp(ctx context.Context, key string) (*model.Response, e
 }
 
 func (lfu *LFUCache) update(node *list.Element) {
+	if node == nil {
+		return
+	}
 	parent := node.Value.(*LfuNode).parent
 	count := parent.counter
 	freqList := parent.lruCache

pkg/storage/memory-lru.go

@@ -84,8 +84,8 @@ func (lru *LRUCache) LookUp(ctx context.Context, key string) (*model.Response, e
 	proc := make(chan *model.Response, 1)
 
 	go func() {
-		lru.mtx.RLock()
-		defer lru.mtx.RUnlock()
+		lru.mtx.Lock()
+		defer lru.mtx.Unlock()
 
 		if value, found := lru.cache[key]; found {
 			lru.responses.MoveToFront(value)

race.js

@@ -0,0 +1,27 @@
+import http from "k6/http";
+
+function getRandomNumberBetween(end) {
+  return Math.floor(Math.random() * end) + 1;
+}
+
+export default function () {
+  for (let id = 1; id <= 100; id++) {
+    const randInt = getRandomNumberBetween(100);
+    let url;
+    let tag = {};
+    if (randInt % 2 === 0) {
+      url = `http://localhost:8000/headers?utm=${id}`;
+      tag = {
+        name: "utm",
+      };
+    } else {
+      url = `http://localhost:8000/headers?bobby=${id}`;
+      tag = {
+        name: "bobby",
+      };
+    }
+    http.get(url, {
+      tags: tag,
+    });
+  }
+}