System and methods for a fast and scalable synchronization server

• US 20020078072A1
• Filed: 12/14/2000
• Published: 06/20/2002
• Est. Priority Date: 01/04/2000
• Status: Active Grant

• Current Assignee: Inlovity Limited
• Original Assignee: Starfish Software, Inc. (Nokia Corporation)
• Inventors: Tan, Chong-Kwan, Liu, Quowong Peter, LaRue, Chris
• Granted Patent: US 6,625,621 B2
• Time in Patent Office: Days
• US Class Current: 707/201
• CPC Class Codes: G06F 9/546 Message passing systems or structures, e.g. queues
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users

Abstract

A sync server responds to messages from a client to synchronize data between a client dataset and a reference dataset. Various messages may be received from the client, including changes to the client dataset, requests for confirmation of received changes, or requests for changes to the reference dataset. When the server receives client changes, the server reads record ID'"'"'s from the messages, writes the ID'"'"'s into a change ID list, and places the changes into a queue for processing. When the server receives a request for confirmation of changes, the server uses the change ID list to confirm receipt of changes, including changes that have not yet been processed. If the server receives a message that requires that the reference dataset be up-to-date, such as a request for changes from the reference dataset, the sync server processes all of the changes in the queue before processing the new message.

Claims

1. A method of synchronizing a client dataset of a synchronization client with a reference dataset of a synchronization server, the method comprising:

receiving at the synchronization server a plurality of synchronization messages from the synchronization client and controlling the queuing of said messages according to the following rules;

if a message is a change message, reading a change identifier from the message and writing the change identifier into a change ID list, placing the message in a queue for possible nonsequential processing, and proceeding to receive another message; and

if a message is not a change message, making the message available for immediate processing as an unqueued message, and waiting until the message is processed before proceeding to receive another message; and

processing said plurality of synchronization messages, according to the following rules;

if there is at least one queued message and there is no unqueued message, processing the next queued message;

if there is an unqueued message and there is no queued message, processing the unqueued message;

if there is at least one queued message and there is an unqueued message, then;

if processing the unqueued message requires that the reference dataset be up-to-date, processing the next queued message;

otherwise

processing the unqueued message,

wherein, processing a change confirmation request message involves reading change identifiers from the change ID list and generating a change confirmation message.

2. The method of claim 1, additionally comprising the step of sending change messages to the synchronization client to indicate changes to be made to the client dataset.

3. The method of claim 1, wherein processing a change message involves performing a conflict resolution and entering the change into a reference dataset if the change survives the conflict resolution.

4. The method of claim 1, wherein messages are sent between the synchronization client and the synchronization server in the form of action objects.

5. The method of claim 1, wherein a change message may comprise an update to an existing data record, an addition of a new data record or a deletion of an existing data record.

6. A method for processing a plurality of synchronization messages received from a synchronization client, the method comprising:

receiving said plurality of synchronization messages from the synchronization client and controlling the queuing of said messages according to the following rules;

if a message is queueable, placing the message on a queue for possible nonsequential processing and proceeding to receive another message; and

if a message is nonqueueable, making the message available for immediate processing as an unqueued message and waiting until the message is processed before proceeding to receive another message; and

processing said plurality of synchronization messages, according to the following rules;

if there is at least one queued message and there is no unqueued message, processing the next queued message;

if there is an unqueued message and there is no queued message, processing the unqueued message;

if there is at least one queued message and there is an unqueued message, then;

if the unqueued message requires that the queue be cleared before processing the unqueued message, processing the next queued message;

otherwise

processing the unqueued message.

7. The method of claim 6, wherein messages received from the synchronization client are initially placed in an input queue.

8. The method of claim 6, wherein change messages are queueable.

9. The method of claim 8, wherein all other messages are unqueueable.

10. The method of claim 8, additionally comprising the steps of reading a change identifier from each change message, writing the change identifiers to a change ID list, and reading the change identifiers from the change ID list to prepare a change confirmation message.

11. The method of claim 8, wherein processing a change message involves performing a conflict resolution and entering the change into a reference dataset if the change survives the conflict resolution.

13. The synchronizer of claim 12, further comprising a listener for receiving messages from a communications channel between the synchronization client and the synchronizer, and for placing the messages into the input queue.

14. The synchronizer of claim 12, further comprising a smart queue unloader for retrieving messages from the smart queue and making the messages available for processing by the synchronization engine.

15. The synchronizer of claim 12, further comprising a change ID list, wherein, when the smart queue loader receives a change message from the synchronization client, the smart queue loader reads a change identifier from the change message and writes the change identifier into the change ID list, and wherein, when the synchronization engine receives a message requesting confirmation of received changes, the synchronization engine reads change identifiers from the change ID list and prepares a change confirmation message.

16. The synchronizer of claim 12, wherein the synchronizer also synchronizes data records on other synchronization clients with data records in corresponding reference datasets.

17. The synchronizer of claim 16, wherein the synchronizer works with multiple instances of each of the listener, the smart queue loader and the smart queue unloader to synchronize with multiple synchronization clients.

18. The synchronizer of claim 12, further comprising an output queue for queuing messages from the synchronizer server to the synchronizer client.

19. The synchronizer of claim 18, further comprising a writer for receiving messages from the output queue, and for placing the messages onto a communications channel between the synchronization client and the synchronizer.

20. The synchronizer of claim 12, wherein the smart queue may be disabled, and, when the smart queue is disabled, all messages are passed directly from the smart queue loader to the synchronization engine.

12. A synchronizer for synchronizing data records on a synchronization client with data records in a reference dataset wherein the synchronization client sends messages to the synchronizer during a synchronization process, the synchronizer comprising:

an input queue for initially queuing messages received from the synchronization client;

a smart queue for queuing messages that are determined to be queueable;

a smart queue loader for retrieving a message from the input queue and, if the message is queueable, placing the message on the smart queue and proceeding to retrieve another message from the input queue, or, if the message is not queueable, making the message available for immediate processing as an unqueued messaged and waiting until the message is processed before proceeding to retrieve another message from the input queue; and

a synchronization engine for receiving messages one at a time from either the smart queue or directly from the smart queue loader, processing the synchronization messages, and making any required changes to the reference dataset, wherein the synchronization engine receives messages from the smart queue or the smart queue loader according to the following rules;

if there is at least one queued message and there is no unqueued message, receiving and processing the next queued message;

if there is an unqueued message and there is no queued message, receiving and processing the unqueued message;

if there is at least one queued message and there is an unqueued message, then;

if the unqueued message requires that the queue be cleared before processing the unqueued message, receiving and processing the next queued message;

otherwise

receiving and processing the unqueued message.