MasterLinux's suppliers have been receiving thousands of duplicate orders since 09:30

MasterLinux continuously buys the equipment for its courses (Raspberry Pi kits for the labs, books, certification vouchers) from about ten suppliers. Purchase orders are sent automatically by the routage-commandes service, which runs on a fleet of eight servers behind the HAProxy load balancer ml-lb-01: ml-routage-01 to -04 in the Casablanca datacenter, ml-routage-05 to -08 on Azure (francecentral). Orders and every send are recorded in the PostgreSQL database achats on ml-db-01. Feature flags are read live from Consul KV.

This morning at 09:12, the team deployed v5.2 with Ansible (pipeline “green”). At 09:30, the product owner activated the new batch sending feature, controlled by the MODE_RAPIDE flag.

Since then, suppliers have been calling: one has received the same order of 40 kits 1,840 times, another is already invoicing duplicate books. Every minute adds several hundred sends. The CTO wants to roll back to v4.9 everywhere, right now; the security team wonders whether the supplier API is under attack.

You are the on-call DevOps engineer, on ml-bastion (Ansible, Consul, Azure CLI, service repository in ~/src/routage-commandes), with SSH access to ml-db-01 and to the routing servers.