Failover monitoring using dynamic traffic tagging

1 . A method, comprising:

outputting first failover information, the first failover information including a first designation of a first network location as a current failover location, wherein the first failover information is received by one or more server devices;

receiving, from a first server device of the one or more server devices at the first network location, a first failover status message, comprising:

a first indication that the first server device received a first request message, the first request message including the current failover location; and

a second indication that the first network location matches the current failover location;

outputting second failover information, the second failover information including a second designation of a second network location as the current failover location, wherein the second failover information is received by the one or more server devices;

receiving, from the first server device at the first network location, a second failover status message, comprising:

a third indication that the first server device received a second request message, the second request message including the current failover location; and

a fourth indication that the first network location does not match the current failover location;

outputting a failover failure notification, the failover failure notification including the fourth indication that the first network location does not match the current failover location; and

responsive to the first network location not matching the current failover location, outputting a failover corrective action, the failover corrective action including a command to cause the first network location to match the current failover location.

2 . The method of claim 1 , further comprising:

receiving, from a second server device of the one or more server devices at the second network location, a third failover status message, comprising:

a fifth indication that the second server device received a third request message, the third request message including the current failover location; and

a sixth indication that the second network location matches the current failover location; and

wherein the current failover location is added to the third request message by a fourth server device of the one or more server devices at the first network location.

3 . The method of claim 2 , wherein adding the current failover location to the third request message by the fourth server device at the first network location comprises:

receiving the third request message;

determining that the first network location does not match the current failover location;

updating the third request message to include the current failover location; and

outputting the third request message to cause the third request message to be forwarded to the second network location.

4 . The method of claim 3 , wherein, upon receiving the third request message by the fourth server device at the first network location, the third request message does not include the current failover location.

5 . The method of claim 2 , wherein:

the fourth server device at the first network location is executing a network application;

the current failover location is added to the third request message by an extension of the network application; and

the fifth and sixth indications are generated by the extension of the network application.

6 . The method of claim 1 , wherein the current failover location is included in the first and second request messages by a network client application.

7 . The method of claim 1 , wherein the first request message is a first Hypertext Transfer Protocol (HTTP) request message and the second request message is a second HTTP request message.

8 . The method of claim 7 , wherein the current failover location is included in an HTTP header of the first and second HTTP request messages.

9 . The method of claim 7 , wherein the current failover location is included in a body of the first and second HTTP request messages and the current failover location is included in a JavaScript Object Notation (JSON) object.

10 . The method of claim 1 , wherein the first failover information is received by the first server device during an initialization process and in response to a query.

11 . The method of claim 1 , wherein the first failover information is received by the first server device periodically in response to periodic queries.

12 . The method of claim 1 , wherein:

the first failover information and the second failover information are broadcast messages; and

the first server device receives the first failover information and the second failover information in response a subscription to a message queue.

13 . The method of claim 1 , wherein the command to cause the first network location to match the current failover location includes instructions for updating one or more configuration settings.

14 . The method of claim 1 , wherein the command to cause the first network location to match the current failover location includes instructions to resend the second failover information.

15 . A non-transitory computer-readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations including:

outputting first failover information, the first failover information including a first designation of a first network location as a current failover location, wherein the first failover information is received by one or more server devices;

receiving, from a first server device of the one or more server devices at the first network location, a first failover status message, comprising:

a first indication that the first server device received a first request message, the first request message including the current failover location; and

a second indication that the first network location matches the current failover location;

outputting second failover information, the second failover information including a second designation of a second network location as the current failover location, wherein the second failover information is received by the one or more server devices;

receiving, from the first server device at the first network location, a second failover status message, comprising:

a third indication that the first server device received a second request message, the second request message including the current failover location; and

a fourth indication that the first network location does not match the current failover location;

outputting a failover failure notification, the failover failure notification including the fourth indication that the first network location does not match the current failover location; and

responsive to the first network location not matching the current failover location, outputting a failover corrective action, the failover corrective action including a command to cause the first network location to match the current failover location.

16 . The non-transitory computer-readable medium of claim 15 , further comprising instructions to cause the one or more processors to perform the operations:

receiving, from a second server device of the one or more server devices at the second network location, a third failover status message, comprising:

a fifth indication that the second server device received a third request message, the third request message including the current failover location; and

a sixth indication that the second network location matches the current failover location; and

wherein the current failover location is added to the third request message by a network application executing on a fourth server device of the one or more server devices at the first network location.

17 . The non-transitory computer-readable medium of claim 16 , wherein the network application includes an extension generated using a software development kit (SDK).

18 . A system comprising:

one or more processors; and

one or more computer-readable storage media storing instructions which, when executed by the one or more processors, cause the one or more processors to perform operations including:

outputting first failover information, the first failover information including a first designation of a first network location as a current failover location, wherein the first failover information is received by one or more server devices;

receiving, from a first server device of the one or more server devices at the first network location, a first failover status message, comprising:

a first indication that the first server device received a first request message, the first request message including the current failover location; and

a second indication that the first network location matches the current failover location;

outputting second failover information, the second failover information including a second designation of a second network location as the current failover location, wherein the second failover information is received by the one or more server devices;

receiving, from the first server device at the first network location, a second failover status message, comprising:

a third indication that the first server device received a second request message, the second request message including the current failover location; and

a fourth indication that the first network location does not match the current failover location;

outputting a failover failure notification, the failover failure notification including the fourth indication that the first network location does not match the current failover location; and

responsive to the first network location not matching the current failover location, outputting a failover corrective action, the failover corrective action including a command to cause the first network location to match the current failover location.

19 . The system of claim 18 , further comprising instructions to cause the one or more processors to perform the operations:

receiving, from a second server device of the one or more server devices at the second network location, a third failover status message, comprising:

a fifth indication that the second server device received a third request message, the third request message including the current failover location; and

a sixth indication that the second network location matches the current failover location; and

wherein the current failover location is added to the third request message by a network application extension executing on a fourth server of the one or more server devices at the first network location.

20 . The system of claim 19 , wherein:

the network application extension is generated using an application programming interface (API) included in a software development kit (SDK); and

a build configuration file causes the API to be included in the network application extension.