Client software back off

1. A user device comprising one or more computers and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising:

sending, to a platform comprising a plurality of host servers, a first request originating from client software running on the user device, wherein the first request is directed to a first endpoint of the platform, wherein the first endpoint is a composition of a first domain and a first path;

receiving, in response to the first request and from the platform, a first error that indicates that the platform is overloaded and that the first request was not processed;

determining, by the user device, a back off time;

receiving, from the client software, one or more subsequent requests to the platform originating from the client software that are initiated before the back off time elapses and that are directed to endpoints that are compositions of paths and the first domain and not to endpoints that are compositions of paths and a second domain that is not the first domain;

placing, by the user device, the first request and then the one or more subsequent requests in a back off queue in an order in which the subsequent requests are initiated; and

sending, by the user device and to the platform, the requests in the back off queue after the back off time has elapsed, until the back off queue is empty.

2. The user device of claim 1 , wherein sending the requests in the back off queue comprises sending the requests in the order in which the requests were placed into the back off queue.

3. The user device of claim 1 , wherein determining the back off time comprises setting the back off time from a retry-after value included in the first error that specifies an amount of time the user device should wait before resending the first request.

4. The user device of claim 1 , wherein determining the back off time comprises using a default value specified by the client software as the back off time.

5. The user device of claim 1 , wherein the operations further comprise:

adding new requests originating from the client software that are directed to the first endpoint to the back off queue while the user device is sending the requests in the back off queue to the platform; and

after the back off queue is empty, concurrently sending, to the platform, new requests originating from the client software that are directed to the first endpoint.

6. The user device of claim 1 , wherein the operations further comprise:

receiving a second error that indicates that the platform is overloaded in response to sending a second request taken from the back off queue to the platform;

placing the second request to a head of the back off queue; and

resetting the back off time.

7. The user device of claim 1 , wherein the first request is a request generated automatically by the user device, or is a request generated in response to an action by a user of the user device.

8. The user device of claim 1 , wherein sending the requests in the back off queue comprises sending high-priority requests before sending low-priority requests.

9. One or more non-transitory computer storage media storing instructions that are operable, when executed by a user device comprising one or more computers, to cause the user device to perform operations comprising:

sending, to a platform comprising a plurality of host servers, a first request originating from client software running on the user device, wherein the first request is directed to a first endpoint of the platform, wherein the first endpoint is a composition of a first domain and a first path;

receiving, in response to the first request and from the platform, a first error that indicates that the platform is overloaded and that the first request was not processed;

determining, by the user device, a back off time;

receiving, from the client software, one or more subsequent requests to the platform originating from the client software that are initiated before the back off time elapses and that are directed to endpoints that are compositions of paths and the first domain and not to endpoints that are compositions of paths and a second domain that is not the first domain;

placing, by the user device, the first request and then the one or more subsequent requests in a back off queue in an order in which the subsequent requests are initiated; and

sending, by the user device and to the platform, the requests in the back off queue after the back off time has elapsed, until the back off queue is empty.

10. The one or more non-transitory computer storage media of claim 9 , wherein sending the requests in the back off queue comprises sending the requests in the order in which the requests were placed into the back off queue.

11. The one or more non-transitory computer storage media of claim 9 , wherein determining the back off time comprises setting the back off time from a retry-after value included in the first error that specifies an amount of time the user device should wait before resending the first request.

12. The one or more non-transitory computer storage media of claim 9 , wherein determining the back off time comprises using a default value specified by the client software as the back off time.

13. The one or more non-transitory computer storage media of claim 9 , wherein the operations further comprise:

adding new requests originating from the client software that are directed to the first endpoint to the back off queue while the user device is sending the requests in the back off queue to the platform; and

after the back off queue is empty, concurrently sending, to the platform, new requests originating from the client software that are directed to the first endpoint.

14. The one or more non-transitory computer storage media of claim 9 , wherein the operations further comprise:

receiving a second error that indicates that the platform is overloaded in response to sending a second request taken from the back off queue to the platform;

placing the second request to a head of the back off queue; and

resetting the back off time.

15. The one or more non-transitory computer storage media of claim 9 , wherein the first request is a request generated automatically by the user device, or is a request generated in response to an action by a user of the user device.

16. The one or more non-transitory computer storage media of claim 9 , wherein sending the requests in the back off queue comprises sending high-priority requests before sending low-priority requests.

17. A server system comprising one or more computers configured to transmit to a user device one or more modules of instructions that are operable, when executed by the user device, to cause the user device to perform operations comprising:

sending, to a platform comprising a plurality of host servers, a first request originating from client software running on the user device, wherein the first request is directed to a first endpoint of the platform, wherein the first endpoint is a composition of a first domain and a first path;

receiving, in response to the first request and from the platform, a first error that indicates that the platform is overloaded and that the first request was not processed;

determining, by the user device, a back off time;

receiving, from the client software, one or more subsequent requests to the platform originating from the client software that are initiated before the back off time elapses and that are directed endpoints that are compositions of paths and the first domain and not to endpoints that are compositions of paths and a second domain that is not the first domain;

placing, by the user device, the first request and then the one or more subsequent requests in a back off queue in an order in which the subsequent requests are initiated; and

sending, by the user device and to the platform, the requests in the back off queue after the back off time has elapsed, until the back off queue is empty.

18. The server system of claim 15 , wherein sending the requests in the back off queue comprises sending the requests in the order in which the requests were placed into the back off queue.

19. The server system of claim 15 , wherein the operations further comprise:

adding new requests originating from the client software that are directed to the first endpoint to the back off queue while the user device is sending the requests in the back off queue to the platform; and

after the back off queue is empty, concurrently sending, to the platform, new requests originating from the client software that are directed to the first endpoint.

20. The server system of claim 15 , wherein sending the requests in the back off queue comprises sending high-priority requests before sending low-priority requests.

21. The server system of claim 15 , wherein determining the back off time comprises setting the back off time from a retry-after value included in the first error that specifies an amount of time the user device should wait before resending the first request.

22. The server system of claim 15 , wherein determining the back off time comprises using a default value specified by the client software as the back off time.

23. The server system of claim 15 , wherein the operations further comprise:

receiving a second error that indicates that the platform is overloaded in response to sending a second request taken from the back off queue to the platform;

placing the second request to a head of the back off queue; and

resetting the back off time.

24. The server system of claim 15 , wherein the first request is a request generated automatically by the user device, or is a request in response to an action by a user of the user device.