1. A method comprising: receiving a request to launch a clustered computing application on a cluster of nodes, each node in the cluster being a virtual instance of a machine within a virtualization service; monitoring, using a processor of a control server, a status of the nodes in the cluster to determine an availability of a database server within the virtualization service; in response to the determining of the availability of the database server, sending a notification message to an application server, the notification message including information for the application server to connect to the database server; in response to determining that the database server and the application server have started, configuring a load balancer to deliver messages to the application server; and subsequent to launching the clustered computing application, automatically changing a size of the cluster based on data for the clustered computing application and on cluster-sizing rules.