System and method for routing content based on real-time feedback

1. A method comprising:

receiving, at a first cache server, a content request from a client system;

determining that the first cache server is overloaded in response to receiving the content request;

in response to determining that the first cache server is overloaded, returning, to the client system, a domain redirection response including a load status of the first cache server, wherein the domain redirection response includes an encoded status string indicating the load status of the first cache server, wherein the encoded status string is appended to a domain name request from the client system, wherein the encoded status string includes an identifier that indicates the first cache server is a source of domain redirection, and wherein the encoded status string is decoded from the domain name request to enable the client system to determine where to send the content request;

receiving, at a domain name system server, the domain name request from the client system, wherein the domain name request includes the load status;

in response to receiving the domain name request, determining, at the domain name system server, that a second cache server can fulfill the content request for a lower network cost than the first cache server; and

returning, to the client system, a domain name reply for the content request that directs the content request to the second cache server, wherein the domain name reply includes a first counter field that provides an indication to the second cache server that the second cache server is a second server to receive the content request.

2. The method of claim 1 , wherein:

the content request is for content from a domain name; and

the domain redirection response further includes a load status field that encodes the load status of the first cache server, and that is appended to the domain name.

3. The method of claim 2 , wherein the load status field further includes an internet protocol address of the client system.

4. The method of claim 2 , wherein the load status field includes an overload field that provides a quantitative indication of how overloaded the first cache server is.

5. The method of claim 2 , wherein the load status field includes a second counter field that indicates that the first cache server is a first server to return the domain redirection response for the content request.

6. The method of claim 1 , wherein in further response to determining that the first cache server is overloaded, the method further comprises:

determining that the content request includes a second counter field;

determining that a counter value of the second counter field is greater than a counter threshold; and

if the second counter field is greater than the counter threshold, satisfying the content request.

7. The method of claim 1 , further comprising determining routing based on the encoded status string.

8. A cache server comprising:

a memory that stores instructions; and

a processor that executes the instructions to perform operations, the operations comprising:

receiving, at a first cache server, a content request from a client system;

determining that the first cache server is overloaded in response to receiving the content request;

in response to determining that the first cache server is overloaded, returning, to the client system, a domain redirection response including a load status of the first cache server, wherein the domain redirection response includes an encoded status string indicating the load status of the first cache server, wherein the encoded status string is appended to a domain name request from the client system, wherein the encoded status string includes an identifier that indicates the first cache server is a source of domain redirection, and wherein the encoded status string is decoded from the domain name request to enable the client system to determine where to send the content request;

receiving, at a domain name system server, the domain name request from the client system, wherein the domain name request includes the load status;

in response to receiving the domain name request, determining, at the domain name system server, that a second cache server can fulfill the content request for a lower network cost than the first cache server; and

returning, to the client system, a domain name reply for the content request that directs the content request to the second cache server, wherein the domain name reply includes a first counter field that provides an indication to the second cache server that the second cache server is a second server to receive the content request.

9. The cache server of claim 8 , wherein:

the content request is for content from a domain name; and

the domain redirection response further includes a load status field that encodes the load status of the first cache server, and that is appended to the domain name.

10. The cache server of claim 9 , wherein the load status field further includes an internet protocol address of the client system.

11. The cache server of claim 9 , wherein the load status field includes an overload field that provides a quantitative indication of how overloaded the first cache server is.

12. The cache server of claim 9 , wherein the load status field includes a second counter field that indicates that the first cache server is a first server to return the domain redirection response for the content request.

13. The cache server of claim 8 , wherein in further response to determining that the first cache server is overloaded, the operations further comprise:

determining that the content request includes a second counter field;

determining that a counter value of the second counter field is greater than a counter threshold; and

if the second counter field is greater than the counter threshold, satisfying the content request.

14. A non-transitory computer-readable medium comprising instructions, which, when loaded and executed by a processor, cause the processor to perform operations, the operations comprising:

receiving, at a first cache server, a content request from a client system;

determining that the first cache server is overloaded in response to receiving the content request;

in response to determining that the first cache server is overloaded, returning, to the client system, a domain redirection response including a load status of the first cache server, wherein the domain redirection response includes an encoded status string indicating the load status of the first cache server, wherein the encoded status string is appended to a domain name request from the client system, wherein the encoded status string includes an identifier that indicates the first cache server is a source of domain redirection, and wherein the encoded status string is decoded from the domain name request to enable the client system to determine where to send the content request;

receiving, at a domain name system server, the domain name request from the client system, wherein the domain name request includes the load status;

in response to receiving the domain name request, determining, at the domain name system server, that a second cache server can fulfill the content request for a lower network cost than the first cache server; and

returning, to the client system, a domain name reply for the content request that directs the content request to the second cache server, wherein the domain name reply includes a first counter field that provides an indication to the second cache server that the second cache server is a second server to receive the content request.

15. The non-transitory computer-readable medium of claim 14 , wherein:

the content request is for content from a domain name; and

the domain redirection response further includes a load status field that encodes the load status of the first cache server, and that is appended to the domain name.

16. The non-transitory computer-readable medium of claim 15 , wherein the load status field further includes an internet protocol address of the client system.

17. The non-transitory computer-readable medium of claim 15 , wherein the load status field includes an overload field that provides a quantitative indication of how overloaded the first cache server is.

18. The non-transitory computer-readable medium of claim 15 , wherein the load status field includes a second counter field that indicates that the first cache server is a first server to return the domain redirection response for the content request.

19. The non-transitory computer-readable medium of claim 14 , wherein in further response to determining that the first cache server is overloaded, the operations further comprise:

determining that the content request includes a second counter field;

determining that a counter value of the second counter field is greater than a counter threshold; and

if the second counter field is greater than the counter threshold, satisfying the content request.

20. The non-transitory computer-readable medium of claim 14 , wherein the operations further comprise determining routing based on the encoded status string.