The access layer of AnalyticDB for MySQL is designed with full redundancy and the Multi-Master architecture to improve service capabilities and availability.
The access layer of AnalyticDB for MySQL consists of frontend nodes. Multiple frontend nodes are mounted to the same Server Load Balancer (SLB) instance. SLB is responsible for balancing connections. A master node is elected among frontend nodes. The master node is responsible for heartbeat management and synchronizes the routing information of storage and compute nodes to slave nodes. This way, each frontend node can equally provide services. When one of the frontend nodes is down, SLB is responsible for routing the connection to other frontend nodes without affecting your business. This implements high availability at the access layer.