Deployment

The Helping Hands application can be deployed as a single artifact in an application server. Once the service becomes popular it must be scaled to handle incoming service lookups and order requests. The easiest way to scale the application for incoming requests is to deploy multiple instances of the application and frontend it with a load balancer, as shown in the following diagram. The load balancer then helps to distribute the requests among the deployed instances of the application. Since all the instances use the same database, all of them are always in-sync and have access to consistent data. Consistency is achieved due to the inherent capabilities of the database used for the application; it supports ACID transactions: