lb/BP/2025_002

Backend Service Timeout for Global External Application Load Balancers

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

Description

The default timeout is 30 seconds for external application load balancers and we don’t recommend backend service timeout values greater than 24 hours (86,400 seconds) because Google Cloud periodically restarts GFEs for software updates and other routine maintenance. The longer the backend service timeout value, the more likely it is that Google Cloud terminates TCP connections for maintenance.

Remediation

Implement Retry Logic in Client Systems for Long Running Connections: Ensure client systems can handle retries if the TCP connection cannot remain open for long periods.

Further information

Please refer https://cloud.google.com/load-balancing/docs/https#timeout-bes for more information related to backend service timeout.