The advent of virtualization technologies for computing resources has provided benefits with respect to managing large-scale computing resources for many customers with diverse needs and has allowed various computing resources or computing services to be efficiently and securely shared by multiple customers. For example, virtualization technologies may allow a single physical computing machine to be shared among multiple customers by providing each customer with one or more computing instances hosted by the single physical computing machine using a hypervisor. Each computing instance may be a guest machine acting as a distinct logical computing system that provides a customer with the perception that the customer is the sole operator and administrator of a given virtualized hardware computing resource.
Customers of a service provider may remotely manage the configuration of computing instances using individual commands sent to the computing instances. For example, commands may be used to set configuration attributes for a computing instance, update software installed on a computing instance, stop or start a computing instance, determine a dynamic structure of a distributed application hosted by computing instances, as well as other commands associated with managing computing instances. Commands used to manage the configuration of computing instances may include command parameters, which can be specified by a customer. Example command parameters may include software license keys, network addresses, database connection strings, user IDs, etc. A customer may provide a command parameter and the command parameter may be included in a command invocation sent to one or more computing instances.