Synchronizing data with delayed subscriptions

Patent metadata

Field	Value
Publication number	US-11089133-B1
Application number	US-201715821690-A
Country	US
Kind code	B1
Filing date	Nov 22, 2017
Priority date	Nov 22, 2017
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

A technology is provided for synchronizing data with delayed subscriptions. A request may be received at a data proxy for a data snapshot for an application that has been offline at the client. A subscription may be held for a pre-determined amount of time after the request for the snapshot. The data snapshot may be sent to the client. The data for the subscription may be sent after the pre-determined amount of time.

First claim

What is claimed is:

1. A non-transitory machine readable storage medium having instructions embodied thereon, the instructions when executed cause a processor to perform processing, comprising:
accepting, at a data proxy hosted by a service provider environment, a network connection from a client to enable the client to come online after the client has been offline for a period of time after having been previously connected to the data proxy;
receiving, at the data proxy, a request from the client for a data snapshot for an application at the client, wherein the data snapshot includes data generated while the client was offline;
holding a subscription for update data for a pre-determined amount of time after the request for the data snapshot, wherein the update data for the subscription is generated during the pre-determined amount of time that occurs after the request for the data snapshot;
sending the data snapshot to the client; and
sending the update data for the subscription to the client after the pre-determined amount of time.

2. The non-transitory machine readable storage medium of claim 1 , further comprising:
tracking a time difference between the network connection and the request for the data snapshot; and
basing the pre-determined amount of time on the time difference between the network connection and the request for the data snapshot.

3. The non-transitory machine readable storage medium of claim 1 , further comprising:
receiving a mutation at the data proxy from the client, wherein the mutation is one of a plurality of mutations that were optimistically cached and serially ordered at the client while the client was offline.

4. The non-transitory machine readable storage medium of claim 1 ,
wherein the data for the subscription is sent using at least one of: Message Queue Telemetry Transport (MQTT) protocol, WebSocket protocol, or long polling.

5. A method, comprising:
receiving a request for a data snapshot for an application that has come online after the application has been offline for a period of time;
holding a subscription for update data for a pre-determined amount of time after the request for the data snapshot, wherein the update data is generated during the pre-determined amount of time that occurs after the request for the data snapshot;
sending the data snapshot to a client; and
sending the update data for the subscription to the client via a messaging service after the pre-determined amount of time.

6. The method of claim 5 , wherein the data snapshot includes data generated while the client was offline, and the update data for the subscription is generated after a network connection has been made.

7. The method of claim 5 , wherein the pre-determined amount of time is at least 10 seconds.

8. The method of claim 5 , further comprising:
tracking a time difference between a network connection being completed and the request for the data snapshot; and
basing the pre-determined amount of time on the time difference between the network connection being completed and the request for the data snapshot.

9. The method of claim 5 , wherein the update data for the subscription is sent using at least one of: Message Queue Telemetry Transport (MQTT) protocol, WebSocket protocol, or long polling.

10. The method of claim 5 , further comprising:
receiving a mutation at a data proxy from the client; and
applying the mutation to a data source via a data access resolver.

11. The method of claim 10 , wherein the mutation is one of a plurality of mutations that were stored in a cache at the client in a queue while the client was offline and were sent to the data proxy to be applied serially after a network connection is made.

12. The method of claim 10 , wherein the data proxy includes more than one version of a data schema and the mutation is handled by the data proxy using a version of the data schema employed by the client.

13. The method of claim 10 , further comprising:
receiving a conflict notification at the data proxy from the data access resolver for a conflict associated with the mutation at the data source; and
resolving the conflict at the data proxy using a pre-defined function defined in the data proxy.

14. The method of claim 10 , wherein the data source is a data store, and the data store comprises one of: an object data store, a key-value data store, a relational database, or a search service.

15. The method of claim 10 , wherein the data source is a code function that is a segment of program code executing on a code function service.

16. The method of claim 5 , wherein a messaging service is used to deliver messages to the client and the messaging service is based on a publish-subscribe model, wherein messages are sent to topics subscribed to by the client.

17. A system, comprising:
a data proxy;
at least one processor; and
a memory device including instructions to be executed by the at least one processor in order to:
accept, at a data proxy, a network connection from a client to enable the client to come online after the client has been offline for a period of time;
receive, at the data proxy, a request for a data snapshot for an application that has been offline;
hold a subscription for update data for a pre-determined amount of time after the request for the data snapshot, wherein the update data is generated during the pre-determined amount of time that occurs after the request for the data snapshot;
send the data snapshot to the client;
send the update data for the subscription after the pre-determined amount of time; and
receive a mutation from a queue for the client, wherein the mutation was generated at the client while the client was offline.

18. The system of claim 17 , the memory device including further instructions to be executed by the at least one processor in order to:
track a time difference between the network connection and the request for the data snapshot; and
base the pre-determined amount of time on the time difference between the network connection and the request for the data snapshot.

19. The system of claim 17 , wherein the mutation is one of a plurality of mutations that were optimistically cached and serially ordered at the client while the client was offline.

20. The system of claim 17 , the memory device including further instructions to be executed by the at least one processor in order to:
apply a plurality of mutations from the client in a serial order that was generated at the client.

Assignees

• Amazon Tech Inc

Inventors

• Patel Amit
• Deshpande Rohan
• Shon Lisa Meenhee
• Saligrama Shreeram Karthik
• Dowling Christopher Nathan
• Bailey Jeffrey H
• Boyer Antoine Francois Charles
• Threlkeld Richard
• Paris Michael
• Willingham Michael B
• Srivastava Mohit

Classifications

• H04L67/62

  Establishing a time schedule for servicing the requests · CPC title

• H04L67/1095 Primary

  Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes · CPC title

• H04L67/562

  Brokering proxy services · CPC title

• H04L67/59

  Providing operational support to end devices by off-loading in the network or by emulation, e.g. when they are unavailable · CPC title

• H04L67/01

  Protocols · CPC title