Here, more important weight is given to the server which contains the master database – as you will discover, if the two servers are active at the web and business layers, data is only written to one of the two databases (master) before being replicated to the other (slave). As a result, the server that contains the local master database is more reactive than its counterpart, which experiences a latency of 10 ms between SBG and RBX when writing data through the vRack (private network that interconnects the two machines). The reason that more requests (60%) are sent to the first server to be treated is for the purpose of load balancing.
Load Balancing IP also plays a role in infrastructure availability: if one server is unavailable - verifying ping on ports, http (80), HTTPS (443), MySQL (3306) or PostgreSQL (5432) - traffic will not be directed to that equipment until it becomes once again available.
Finally, an SSL certificate is associated with the LB IP, securing user connections to the infrastructure.