Abstract: Methods, systems, and apparatus, including computer program apparatus, implementing techniques for publishing, subscribing to, or playing live appliances. A live appliance includes a current virtual machine image. In publishing, a proxy file of a live appliance file type is provided to the publisher. The type is mapped to a live appliance player; so that when a proxy file is opened, the current virtual machine image is run. The player automatically binds a writeable file system external to the virtual machine image to the image to provide file storage that is accessible from within the virtual machine image and from a host operating system. The player also creates a subscription to the live appliance on the host computer if one does not exist when the proxy file is run. With the subscription, the player runs the then-current virtual machine image whenever the live appliance is run.

Abstract: Methods, systems, and apparatus, including computer program apparatus, implementing techniques for publishing, subscribing to, or playing live appliances. A live appliance includes a current virtual machine image. In publishing, a proxy file of a live appliance file type is provided to the publisher. The type is mapped to a live appliance player; so that when a proxy file is opened, the current virtual machine image is run. The player automatically binds a writeable file system external to the virtual machine image to the image to provide file storage that is accessible from within the virtual machine image and from a host operating system. The player also creates a subscription to the live appliance on the host computer if one does not exist when the proxy file is run. With the subscription, the player runs the then-current virtual machine image whenever the live appliance is run.

Abstract: Methods, systems, and apparatus, including computer program apparatus, implementing techniques for publishing, subscribing to, or playing live appliances. A live appliance includes a current virtual machine image. In publishing, a proxy file of a live appliance file type is provided to the publisher. The type is mapped to a live appliance player; so that when a proxy file is opened, the current virtual machine image is run. The player automatically binds a writeable file system external to the virtual machine image to the image to provide file storage that is accessible from within the virtual machine image and from a host operating system. The player also creates a subscription to the live appliance on the host computer if one does not exist when the proxy file is run. With the subscription, the player runs the then-current virtual machine image whenever the live appliance is run.

Abstract: A tiered distribution service is provided in a content delivery network (CDN) having a set of surrogate origin (namely, “edge”) servers organized into regions and that provide content delivery on behalf of participating content providers, wherein a given content provider operates an origin server. According to the invention, a cache hierarchy is established in the CDN comprising a given edge server region and either (a) a single parent region, or (b) a subset of the edge server regions. In response to a determination that a given object request cannot be serviced in the given edge region, instead of contacting the origin server, the request is provided to either the single parent region or to a given one of the subset of edge server regions for handling, preferably as a function of metadata associated with the given object request. The given object request is then serviced, if possible, by a given CDN server in either the single parent region or the given subset region.

Abstract: A file transport mechanism according to the invention is responsible for accepting, storing and distributing files, such as configuration or control files, to a large number of field machines. The mechanism is comprised of a set of servers that accept, store and maintain submitted files. The file transport mechanism implements a distributed agreement protocol based on “vector exchange.” A vector exchange is a knowledge-based algorithm that works by passing around to potential participants a commitment bit vector. A participant that observes a quorum of commit bits in a vector assumes agreement. Servers use vector exchange to achieve consensus on file submissions. Once a server learns of an agreement, it persistently marks (in a local data store) the request as “agreed.” Once the submission is agreed, the server can stage the new file for download.