A computer-implemented method for validating the resiliency of a networked application, the method comprising: identifying a plurality of active application components within a network used to provide the networked application, wherein each of the plurality of active application components comprises a virtual machine instance executing in a computing cloud, wherein auto scaling is used in the computing cloud to automatically scale up or down a number of virtual machine instances allocated to a given application component based on need at a given time; selecting at least one of the identified application components based on: a corresponding virtual machine instance being a member of a first auto scaling group included in a plurality of different auto scaling groups, and a selection criteria that excludes virtual machine instances that are members of a security group specifying one or more network access rules applied to the members of the security group and virtual machine instances that, when failed, are known to be disruptive to other virtual machine instances; terminating the selected active application component; and following the termination of the selected active application component, monitoring the actions of one or more remaining active application components within the network to evaluate the functioning of the auto scaling against randomly occurring server failures; and creating one or more log entries recording information corresponding to the actions of the remaining active application components resulting from the termination of the selected active application component. identifying a plurality of active application components within a network used to provide the networked application, wherein each of the plurality of active application components comprises a virtual machine instance executing in a computing cloud, wherein auto scaling is used in the computing cloud to automatically scale up or down a number of virtual machine instances allocated to a given application component based on need at a given time; selecting at least one of the identified application components based on: a corresponding virtual machine instance being a member of a first auto scaling group included in a plurality of different auto scaling groups, and a selection criteria that excludes virtual machine instances that are members of a security group specifying one or more network access rules applied to the members of the security group and virtual machine instances that, when failed, are known to be disruptive to other virtual machine instances; a corresponding virtual machine instance being a member of a first auto scaling group included in a plurality of different auto scaling groups, and a selection criteria that excludes virtual machine instances that are members of a security group specifying one or more network access rules applied to the members of the security group and virtual machine instances that, when failed, are known to be disruptive to other virtual machine instances; terminating the selected active application component; and following the termination of the selected active application component, monitoring the actions of one or more remaining active application components within the network to evaluate the functioning of the auto scaling against randomly occurring server failures; and creating one or more log entries recording information corresponding to the actions of the remaining active application components resulting from the termination of the selected active application component. <EOS>