Which service provides application-level load balancing?

Alibaba Cloud Application Load Balancer (ALB) operates at Layer 7 (Application Layer) of the OSI model. It is specifically optimized for high-performance application-level load balancing, supporting protocols such as HTTP, HTTPS, and QUIC. ALB offers advanced content-based routing rules based on URLs, HTTP headers, hostnames, and query strings to distribute application traffic effectively.

B: Network Load Balancer (NLB) operates at Layer 4 (Transport Layer), processing high-throughput TCP, UDP, and TLS connections rather than handling application-layer protocols or HTTP routing rules. C: Classic Load Balancer (CLB) is a legacy load balancer supporting basic Layer 4 and Layer 7 features, whereas ALB is Alibaba Cloud's dedicated, modern Layer 7 load balancer. D: Object Storage Service (OSS) is an encrypted, scalable cloud object storage service for unstructured data, not a load balancing service.

- Alibaba Cloud ALB Documentation: "What is Application Load Balancer?" (https://www.alibabacloud.com/help/en/slb/application-load-balancer/product-overview/what-is-alb)

- Alibaba Cloud Server Load Balancer Overview: "Layer 7 Load Balancing Capabilities" (https://www.alibabacloud.com/help/en/slb/user-guide/slb-overview)