Amane Taamine: online claim submissions fail with “Unable to save”

Amane Taamine Assurances (a fictional car and home insurer) lets its policyholders file a claim online at sinistres.amanetaamine.ma. The application runs on ECS and writes to an Amazon RDS for PostgreSQL 16 database: amane-sinistres-prod.

Since 10:58, every form submission ends with “Unable to save, please try again later” (« Enregistrement impossible, réessayez plus tard »). Viewing existing claims still works at times. The claims department is getting calls from policyholders who had an accident this morning.

The on-call developer thinks of “a lock in the database” or “too many connections”. You are the on-call cloud engineer, with the AWS CLI v2 (region eu-west-3).