Using virtual domain name service (DNS) zones for enterprise content delivery
A domain to be published to an enterprise ECDN is associated (either by static configuration or dynamically) with a set of one or more enterprise zones configurable in a hierarchy. When a DNS query arrives for a hostname known to be associated with given content within the control of the ECDN, a DNS server preferably responds in one of three (3) ways: (a) handing back an IP address, e.g., for an ECDN intelligent node that knows how to obtain the requested content from a surrogate or origin server; (b) executing a zone referral to a next (lower) level name server in a zone hierarchy, or (c) CNAMing to another hostname, thereby essentially restarting the lookup procedure. In the latter case, this new CNAME causes the resolution process to start back at the root and resolve a new path, probably along a different path in the hierarchy. At any particular level in the zone hierarchy, preferably there is an associated zone server. That server preferably executes logic that applies the requested hostname against a map, which, using known techniques, may be generated from given (static, dynamic, internally-generated or third party-sourced) performance metrics. Thus, a given name query to ECDN-managed content may be serviced in coordination with various sources of distributed network intelligence. As a result, the invention provides for a distributed, dynamic globally load balanced name service.
1. A method of content delivery, comprising:
having an entity establish an enterprise content delivery network (ECDN) behind an enterprise firewall, wherein the entity has a private namespace that is not resolvable through public Internet DNS, the private namespace having a set of enterprise domains associated therewith;
building a list of one or more enterprise domains that are candidates for caching in the ECDN, wherein an enterprise domain that is a candidate for caching has associated therewith a set of one or more IP addresses associated with nearby content servers managed as part of an Internet content delivery network (ICDN);
upon receipt of a query to a domain, the request generated by an end user behind the enterprise firewall, determining if the domain is on the list;
if the domain is on the list, returning a response to the query identifying an ECDN virtual zone; and
resolving the ECDN virtual zone to identify a given one of the one or more IP addresses.
2. The method as described in claim 1 wherein the list of one or more enterprise domains is built based on recorded usage patterns of address record lookups.
3. The method as described in claim 2 further including the step of modifying the list as the recorded usage patterns change.
4. The method as described in claim 1 further including selectively removing the domain from the list.
5. The method as described in claim 4 wherein the domain is removed from the list if usage patterns associated with the domain indicate that the domain is not of high interest.
6. The method as described in claim 1 wherein the ECDN virtual zone is created dynamically when the enterprise domain is added to the list.
7. The method as described in claim 6 wherein the ECDN virtual zone is resolved without reference to the public Internet DNS.