{"id":"67c5ac08fafc3b7f","repo":"gofiber/fiber","slug":"cache-failed-to-get-key-q-from-storage-w","errorCode":null,"errorMessage":"cache: failed to get key %q from storage: %w","messagePattern":"cache: failed to get key %q from storage: %w","errorType":"http","errorClass":null,"httpStatus":null,"severity":"error","filePath":"middleware/cache/manager.go","lineNumber":114,"sourceCode":"\te.status = 0\n\te.age = 0\n\te.exp = 0\n\te.ttl = 0\n\te.forceRevalidate = false\n\te.revalidate = false\n\te.headers = nil\n\te.shareable = false\n\te.private = false\n\te.heapidx = 0\n\tm.pool.Put(e)\n}\n\n// get data from storage or memory\nfunc (m *manager) get(ctx context.Context, key string) (*item, error) {\n\tif m.storage != nil {\n\t\traw, err := m.storage.GetWithContext(ctx, key)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"cache: failed to get key %q from storage: %w\", m.logKey(key), err)\n\t\t}\n\t\tif raw == nil {\n\t\t\treturn nil, errCacheMiss\n\t\t}\n\n\t\tit := m.acquire()\n\t\tif _, err := it.UnmarshalMsg(raw); err != nil {\n\t\t\tm.release(it)\n\t\t\treturn nil, fmt.Errorf(\"cache: failed to unmarshal key %q: %w\", m.logKey(key), err)\n\t\t}\n\n\t\treturn it, nil\n\t}\n\n\tif value := m.memory.Get(key); value != nil {\n\t\tit, ok := value.(*item)\n\t\tif !ok {\n\t\t\treturn nil, fmt.Errorf(\"cache: unexpected entry type %T for key %q\", value, m.logKey(key))","sourceCodeStart":96,"sourceCodeEnd":132,"githubUrl":"https://github.com/gofiber/fiber/blob/9a4c7e57fe0b080a04235d28a4b0d2b4b353d58c/middleware/cache/manager.go#L96-L132","documentation":"Thrown by the cache middleware's manager.get() at middleware/cache/manager.go:114 when the configured fiber.Storage backend returns a non-nil error from GetWithContext while reading a cache entry. The wrapped %w is the raw driver error (Redis/MySQL/SQLite/etc.). It means the storage layer itself is failing, not that the key is missing (a miss returns the internal errCacheMiss sentinel instead).","triggerScenarios":"Cache middleware is configured with Storage: someStorage (e.g. storage.Redis, storage.S3, storage.SQLite) and a request hits a cached route while that backend is unreachable, times out, or returns a query error. The ctx passed to GetWithContext may also be cancelled, surfacing as context.Canceled / context.DeadlineExceeded inside the wrapped error.","commonSituations":"Redis connection dropped or AUTH expired; DB connection pool exhausted under load; storage pods restarted during a deploy; client request cancelled (ctx done) before the storage GET returns; network partition between the app and the storage host; misconfigured storage TLS.","solutions":["Inspect the wrapped error string for the underlying driver cause (e.g. 'connection refused', 'i/o timeout', 'context deadline exceeded') and fix that specific backend issue.","Verify the storage instance is healthy and reachable from the app pod (ping / health-check the endpoint configured on the storage driver).","If the wrapped error is context.DeadlineExceeded, raise the storage driver's read timeout or the fiber handler's per-request timeout to exceed typical backend latency.","Add connection-pool tuning / retries on the storage driver (e.g. Redis PoolSize, MinIdleConns) to survive transient failures.","Wire a fiber.ErrorHandler that logs the storage error and degrades gracefully (serves an uncached response) instead of 500-ing every request when storage flaps."],"exampleFix":"// before\napp.Use(cache.New(cache.Config{\n    Storage: redis.New(), // no timeout, no pool tuning\n}))\n\n// after\nstore := redis.New(redis.Config{\n    URL:   os.Getenv(\"REDIS_URL\"),\n    PoolSize: 50,\n})\nif err := store.Reset(); err != nil { // sanity check connectivity at boot\n    log.Fatalf(\"cache storage unreachable: %v\", err)\n}\napp.Use(cache.New(cache.Config{ Storage: store }))","handlingStrategy":"try-catch","validationCode":"// At boot, confirm the storage backend is reachable before wiring the cache.\nctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)\ndefer cancel()\nif _, err := store.GetWithContext(ctx, \"__healthcheck__\"); err != nil {\n    log.Fatalf(\"cache storage unhealthy: %v\", err)\n}","typeGuard":null,"tryCatchPattern":"// cache errors bubble through fiber's error handler; log + degrade there.\napp.ErrorHandler = func(c fiber.Ctx, err error) error {\n    if strings.Contains(err.Error(), \"cache: failed to get key\") {\n        log.Printf(\"cache read failed (serving uncached): %v\", err)\n        return c.Next()\n    }\n    return fiber.DefaultErrorHandler(c, err)\n}","preventionTips":["Health-check the storage endpoint at app startup so misconfig fails fast.","Set the storage driver's read timeout below the per-request context deadline.","Tune connection pool size (e.g. Redis PoolSize) for your peak RPS.","Monitor storage latency and error rate; alert before it cascades into the app."],"tags":["cache","storage","network","redis","fiber"],"analyzedSha":"9a4c7e57fe0b080a04235d28a4b0d2b4b353d58c","analyzedAt":"2026-08-04T21:44:03.395Z","schemaVersion":2}