Cluster configuration :

All clusters are built on teh same scheme :

2 identical servers
Each machine is the "replica" of the other one.

The hardware configuration varies depending on the load to bear. In production, the main servers have 72 hearts and 1TB of Ram with raid10 nvme disks able to 1.5GB/second.
Some Others Are Azure Virtual Machines with 8 VCPU and 32GB RAM.

The pre-production machine where we detect the problem are virtual machine (ESX)
with 8VCPU and 16GB RAM.