lb/BP/2025_001

Backend Protocol selection for Global External Application Load Balancers

Product: Load balancing
Rule class: BP - Best practice, opinionated recommendation

Description

Your choice of backend protocol (HTTP, HTTPS, or HTTP/2) impacts application latency and the network bandwidth available for your application. For example, using HTTP/2 between the load balancer and the backend instance can require significantly more TCP connections to the instance than HTTP(S). Connection pooling, an optimization that reduces the number of these connections with HTTP(S), is not available with HTTP/2. As a result, you might see high backend latencies because backend connections are made more frequently.

Remediation

For typical web applications and APIs, HTTP or HTTPS generally offer better performance due to connection pooling, which reduces the overhead of establishing new TCP connections for each request. This is especially true if your application experiences many small, frequent requests.

Further information

Please refer https://cloud.google.com/load-balancing/docs/https/http-load-balancing-best-practices#backend_service_protocol_selection for more information related to backend service protocol selection.