Abstract: Business applications running on a content delivery network (CDN) having a distributed application framework can create, access and modify state for each client. Over time, a single client may desire to access a given application on different CDN edge servers within the same region and even across different regions. Each time, the application may need to access the latest “state” of the client even if the state was last modified by an application on a different server. A difficulty arises when a process or a machine that last modified the state dies or is temporarily or permanently unavailable. The present invention provides techniques for migrating session state data across CDN servers in a manner transparent to the user. A distributed application thus can access a latest “state” of a client even if the state was last modified by an application instance executing on a different CDN server, including a nearby (in-region) or a remote (out-of-region) server.

Abstract: A content file purge mechanism for a content delivery network (CDN) is described. A Web-enabled portal is used by CDN customers to enter purge requests securely. A purge request identifies one or more content files to be purged. The purge request is pushed over a secure link from the portal to a purge server, which validates purge requests from multiple CDN customers and batches the requests into an aggregate purge request. The aggregate purge request is pushed from the purge server to a set of staging servers. Periodically, CDN content servers poll the staging servers to determine whether an aggregate purge request exists. If so, the CDN content servers obtain the aggregate purge request and process the request to remove the identified content files from their local storage.

Abstract: An application deployment model for enterprise applications to enable applications to be deployed to and executed from a globally distributed computing platform, such as an Internet content delivery network (CDN). According to the invention, application developers separate their Web application into two layers: a highly distributed edge layer and a centralized origin layer. In a representative embodiment, the edge layer supports a servlet container that executes a Web tier, typically the presentation layer of a given Java-based application. Where necessary, the edge layer communicates with code running on an origin server to respond to a given request. In an alternative embodiment, the edge layer supports a more fully-provisioned application server that executes both Web tier (e.g., presentation) and Enterprise tier application (e.g., business logic) components.

Abstract: A Border Gateway Protocol (BGP) monitoring service is described. The monitoring service receives as input(s) configuration data input from one or more site(s) that desire to obtain the service, as well as BGP feed data received from a set of data collectors positioned at or adjacent BGP peering points. For every origin (IP space) being monitored, a monitoring application monitors a set of allowed or permitted originating Autonomous System (AS) numbers for that space. Thus, for every IP address space being watched (i.e., for each routable block that contains an origin server IP address of interest), the monitoring application continually monitors the set of transit Autonomous Systems for that CIDR block. Using the real-time BGP feeds (and/or the daily updates), the monitoring application looks for updates coming from the routers that impact the CIDR blocks of interest for that particular site(s).

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.