文件缓存增加自动限速/提升本地缓存数据库写入和查询速度

internal/nodes/http_writer.go

@@ -314,7 +314,7 @@ func (this *HTTPWriter) PrepareCache(resp *http.Response, size int64) {
 			remotelogs.Error("HTTP_WRITER", "write cache failed: "+err.Error())
 		}
 
-		this.Header().Set("X-Cache", "BYPASS, open failed")
+		this.Header().Set("X-Cache", "BYPASS, too many requests")
 		return
 	}
 	this.cacheWriter = cacheWriter