Custom responses for resource unavailable errors

1. A method in a proxy server for responding to resource unavailable errors, comprising:

receiving, from a client device, a request for a network resource hosted at an origin server for a domain;

requesting the network resource from the origin server;

receiving at the proxy server a response from the origin server that includes a resource unavailable error that indicates that the requested network resource is unavailable to the origin server; and

responsive to the proxy server receiving the response from the origin server that includes the resource unavailable error, the proxy server performing the following:

creating a custom error page that indicates that the requested network resource is unavailable, wherein the custom error page is different than the received response from the origin server, and

transmitting the custom error page to the client device that indicates that the requested network resource is unavailable.

2. The method of claim 1 , further comprising:

determining that the requested network resource has moved to a different location; and

including in the custom error page a link to the different location for the requested network resource.

3. The method of claim 2 , wherein determining that the requested network resource has moved to a different location includes matching a hash of the requested network resource with one of a plurality of hashes of other network resources hosted by the origin server.

4. The method of claim 1 , wherein the custom error page is customized based on a country of a visitor belonging to the request or a language of the visitor.

5. The method of claim 1 , wherein the request includes a set of one or more terms, and wherein the custom error page is customized based on the set of terms.

6. The method of claim 1 , wherein the custom error page includes a set of one or more links to other network resources available on the domain.

7. The method of claim 1 , wherein the custom error page includes a set of one or more links to other network resources available on a set of one or more domains other than the domain that hosts the requested network resource.

8. The method of claim 1 , wherein the request for the network resource is received at the proxy server because a Domain Name System request for the domain resolves to an IP address of the proxy server.

9. The method of claim 1 , wherein the creating the custom error page includes including cached content from another network resource available on the domain.

10. A non-transitory machine-readable storage medium that provides instructions that, when executed by a processor of a proxy server, cause said processor to perform operations comprising:

receiving, from a client device, a request for a network resource hosted at an origin server for a domain;

requesting the network resource from the origin server;

receiving at the proxy server a response from the origin server that includes a resource unavailable error that indicates that the requested network resource is unavailable to the origin server; and

responsive to the proxy server receiving the response from the origin server that includes the resource unavailable error, the proxy server performing the following:

creating a custom error page that indicates that the requested network resource is unavailable, wherein the custom error page is different than the received response from the origin server, and

transmitting the custom error page to the client device that indicates that the requested network resource is unavailable.

11. The non-transitory machine-readable storage medium of claim 10 , wherein the operations further comprise:

determining that the requested network resource has moved to a different location;

and including in the custom error page a link to the different location for the requested network resource.

12. The non-transitory machine-readable storage medium of claim 11 , wherein determining that the requested network resource has moved to a different location includes matching a hash of the requested network resource with one of a plurality of hashes of other network resources hosted by the origin server.

13. The non-transitory machine-readable storage medium of claim 10 , wherein the custom error page is customized based on a country of a visitor belonging to the request or a language of the visitor.

14. The non-transitory machine-readable storage medium of claim 10 , wherein the request includes a set of one or more terms, and wherein the custom error page is customized based on the set of terms.

15. The non-transitory machine-readable storage medium of claim 10 , wherein the custom error page includes a set of one or more links to other network resources available on the domain.

16. The non-transitory machine-readable storage medium of claim 10 , wherein the custom error page includes a set of one or more links to other network resources available on a set of one or more domains other than the domain that hosts the requested network resource.

17. The non-transitory machine-readable storage medium of claim 10 , wherein the request for the network resource is received at the proxy server because a Domain Name System request for the domain resolves to an IP address of the proxy server.

18. The non-transitory machine-readable storage medium of claim 10 , wherein the creating of the custom error page includes including cached content from another network resource available on the domain.

19. A proxy server, comprising:

a set of one or more processors; and

a non-transitory machine-readable storage medium that stores instructions, that when executed by the set of processors, cause the set of processors to perform operations comprising:

receive, from a client device, a request for a network resource hosted at an origin server for a domain,

request the network resource from the origin server,

receive at the proxy server a response from the origin server that includes a resource unavailable error that indicates that the requested network resource is unavailable to the origin server, and

responsive to receipt at the proxy server of the response from the origin server that includes the resource unavailable error, the set of processors of the proxy server to perform the following:

create a custom error page that indicates that the requested network resource is unavailable, wherein the custom error page is to be different than the received response from the origin server, and

transmit the custom error page to the client device that indicates that the requested network resource is unavailable.

20. The proxy server of claim 19 , wherein the operations further comprise:

determine that the requested network resource has moved to a different location; and

include in the custom error page a link to the different location for the requested network resource.

21. The proxy server of claim 20 , wherein the determination that the requested network resource has moved to a different location includes a match of a hash of the requested network resource with one of a plurality of hashes of other network resources hosted by the origin server.

22. The proxy server of claim 19 , wherein the custom error page is to be customized based on a country of a visitor belonging to the request or a language of the visitor.

23. The proxy server of claim 19 , wherein the request includes a set of one or more terms, and wherein the custom error page is to be customized based on the set of terms.

24. The proxy server of claim 19 , wherein the custom error page is to include a set of one or more links to other network resources available on the domain.

25. The proxy server of claim 19 , wherein the custom error page is to include a set of one or more links to other network resources available on a set of one or more domains other than the domain that hosts the requested network resource.

26. The proxy server of claim 19 , wherein the request for the network resource is to be received at the proxy server because a Domain Name System request for the domain resolves to an IP address of the proxy server.

27. The proxy server of claim 19 , wherein the creation of the custom error page is to include including cached content from another network resource available on the domain.