Abstract: To serve content through a content delivery network (CDN), the CDN must have some information about the identity, characteristics and state of its target objects. Such additional information is provided in the form of object metadata, which according to the invention can be located in the request string itself, in the response headers from the origin server, in a metadata configuration file distributed to CDN servers, or in a per-customer metadata configuration file. CDN content servers execute a request identification and parsing process to locate object metadata and to handle the request in accordance therewith. Where different types of metadata exist for a particular object, metadata in a configuration file is overridden by metadata in a response header or request string, with metadata in the request string taking precedence.

Abstract: To serve content through a content delivery network (CDN), the CDN must have some information about the identity, characteristics and state of its target objects. Such additional information is provided in the form of object metadata, which according to the invention can be located in the request string itself, in the response headers from the origin server, in a metadata configuration file distributed to CDN servers, or in a per-customer metadata configuration file. CDN content servers execute a request identification and parsing process to locate object metadata and to handle the request in accordance therewith. Where different types of metadata exist for a particular object, metadata in a configuration file is overridden by metadata in a response header or request string, with metadata in the request string taking precedence.

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: 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.