This is true if the application needs to talk to the slaves directly. If the application doesn't care, then you could do the smarts in the proxy layer underneat

This is true if the application needs to talk to the slaves directly. If the application doesn't care, then you could do the smarts in the proxy layer underneath the application. I see three scenarios: * Stateless or Transparent master/master backend Example: Memcached cluster Use load balancing in the proxy layer * Failover backend with failover on server side Examples: Mysql master/slave Use failover logic in the proxy layer * Failover backend with failover on the client side Example: HA RabbitMQ cluster Above suggestion from polvi is needed