DISTRIBUTED AVAILABILITY GROUPS OF DATABASES FOR DATA CENTERS INCLUDING FAILOVER TO REGIONS IN DIFFERENT TIME ZONES

• US 20180096068A1
• Filed: 01/10/2017
• Published: 04/05/2018
• Est. Priority Date: 09/30/2016
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: VENKATARAMANAPPA, Girish Mittur, SUN, Zhengguo, TIBREWAL, Varun Kunjbihari, LINDELL, Steven John, VERKHEDKAR, Sameer Arun, LINGAM, Sandeep, NEVILLE, Colin
• Granted Patent: US 10,725,998 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 11/1474 in transactions G06F16/20 takes precedence
• CPC Class Codes: G06F 11/2028 eliminating a faulty processor or activating a spare
• CPC Class Codes: G06F 11/2033 switching over of hardware resources
• CPC Class Codes: G06F 11/2035 without idle spare hardware
• CPC Class Codes: G06F 11/2041 with more than one idle spare processing component
• CPC Class Codes: G06F 11/2048 where the redundant components share neither address space nor persistent storage
• CPC Class Codes: G06F 11/2097 maintaining the standby controller/processing unit updated initialisation or re-synchronisation thereof G06F11/1658 and subgroups
• CPC Class Codes: G06F 16/183 Provision of network file services by network file servers, e.g. by using NFS, CIFS network file access protocols H04L67/1097
• CPC Class Codes: G06F 16/1844 Management specifically adapted to replicated file systems
• CPC Class Codes: G06F 16/2358 Change logging, detection, and notification replication G06F16/27
• CPC Class Codes: G06F 16/2365 Ensuring data consistency and integrity
• CPC Class Codes: G06F 16/2379 Updates performed during online database operations; commit processing
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/273 Asynchronous replication or reconciliation
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: G06F 2201/80 Database-specific techniques
• CPC Class Codes: G06F 2201/805 : Real-time
• CPC Class Codes: G06F 2201/82 : Solving problems relating to consistency

Abstract

A Distributed Availability Group (DAG) spans two AGs, each spanning one or more replica nodes and functioning as primary or secondary AG. A primary AG is replicated to the secondary AG synchronously or asynchronously. A failover in the DAG results in the AGs swapping their roles. Multiple DAGs can be linked together as a chain, which provides many useful features including disaster recovery across geographical regions, massive read scale (numerous readable secondary nodes), online migration of databases (across different operating systems and computing environments). The systems using DAGs can replicate databases across multiple independent high availability (HA) failover clusters using complex replication topologies and allow for manual failover and failback. The systems allow chaining of multiple AGs to provision a treelike structure of replicas and numerous secondary replicas without impacting performance. The systems automatically seed new database replicas to facilitate building a complex topology of DAGs.

Claims

1. A system comprising:

a processor and memory; and

an application executed by the processor and memory to;

perform read and write operations for an online transaction processing system using a relational database on a first server during a first portion of a day during which a second server located in a different geographical location than the first server and having a replica of the relational database on the second server performs read operations for the online transaction processing system; and

perform read operations for the online transaction processing system during a second portion of the day during which the second server performs read and write operations for the online transaction processing system using the replica of the relational database on the second server to increase a response time for the read and write operations performed by the second server during the second portion of the day.

2. The system of claim 1 wherein the application is further configured to send a log file associated with the relational database on the first server from the first server to the second server to replicate the relational database on the second server following a write operation to the relational database on the first server when the first server performs the read and write operations and the second server performs the read operations during the first portion of the day.

3. The system of claim 2 wherein the application is further configured to send the log file along with a corresponding data file from the first server directly to the second server without saving a copy of the log file and the corresponding data file.

4. The system of claim 1 wherein the application is further configured to receive a log file associated with the relational database on the second server from the second server to replicate the relational database on the first server following a write operation to the relational database on the second server when the second server performs the read and write operations and the first server performs the read operations during the second portion of the day.

5. The system of claim 4 wherein the application is further configured to receive the log file along with a corresponding data file from the second server directly to the first server without saving a copy of the log file and the corresponding data file.

6. The system of claim 1 wherein the application is further configured to, during the first portion of the day:

send a log file associated with the relational database on the first server from the first server to the second server following a write operation to the relational database on the first server, wherein the second server is configured to replicate the relational database on the second server using the log file; and

acknowledge the write operation to the relational database on the first server as being successful after receiving a confirmation from the second server that the second server successfully completed replication of the relational database on the second server after receiving the log file.

7. The system of claim 1 wherein the application is further configured to, during the second portion of the day:

receive from the second server a log file associated with the relational database on the second server following a write operation to the relational database on the second server;

replicate the relational database on the first server using the log file; and

send a confirmation from the first server to the second server that the first server successfully completed replication of the relational database on the first server after receiving the log file from the second server,

wherein the second server is configured to acknowledge the write operation to the relational database on the second server as being successful after receiving the confirmation.

8. The system of claim 1 wherein the first and second servers execute different operating systems.

9. The system of claim 1 wherein the first and second servers execute different versions of an operating system.

10. The system of claim 1 wherein one of the first and second servers is located in a cloud-based computing environment.

11. A method comprising:

performing read and write operations for an online transaction processing system using a relational database on a first server during a first portion of a day during which a second server located in a different geographical location than the first server and having a replica of the relational database on the second server performs read operations for the online transaction processing system; and

performing read operations for the online transaction processing system during a second portion of the day during which the second server performs read and write operations for the online transaction processing system using the replica of the relational database on the second server to increase a response time for the read and write operations performed by the second server during the second portion of the day.

12. The method of claim 11 further comprising sending a log file associated with the relational database on the first server from the first server to the second server to replicate the relational database on the second server following a write operation to the relational database on the first server when the first server performs the read and write operations and the second server performs the read operations during the first portion of the day.

13. The method of claim 12 further comprising sending the log file along with a corresponding data file from the first server directly to the second server without saving a copy of the log file and the corresponding data file.

14. The method of claim 11 further comprising receiving a log file associated with the relational database on the second server from the second server to replicate the relational database on the first server following a write operation to the relational database on the second server when the second server performs the read and write operations and the first server performs the read operations during the second portion of the day.

15. The method of claim 14 further comprising receiving the log file along with a corresponding data file from the second server directly to the first server without saving a copy of the log file and the corresponding data file.

16. The method of claim 11 further comprising, during the first portion of the day:

sending a log file associated with the relational database on the first server from the first server to the second server following a write operation to the relational database on the first server, wherein the second server is configured to replicate the relational database on the second server using the log file; and

acknowledging the write operation to the relational database on the first server as being successful after receiving a confirmation from the second server that the second server successfully completed replication of the relational database on the second server after receiving the log file.

17. The method of claim 11 further comprising, during the second portion of the day:

receiving from the second server a log file associated with the relational database on the second server following a write operation to the relational database on the second server;

replicating the relational database on the first server using the log file;

sending a confirmation from the first server to the second server that the first server successfully completed replication of the relational database on the first server after receiving the log file from the second server; and

acknowledging the write operation to the relational database on the second server as being successful after receiving the confirmation.

18. The method of claim 11 further comprising executing different operating systems or different versions of an operating system on the first and second servers.

19. The method of claim 11 wherein one of the first and second servers is located in a cloud-based computing environment.

20. A system comprising:

a processor and memory; and

an application executed by the processor and memory to;

perform read and write operations for an online transaction processing system using a relational database on a first server during a first portion of a day during which a second server located in a different geographical location than the first server and having a replica of the relational database on the second server performs read operations for the online transaction processing system;

perform read operations for the online transaction processing system during a second portion of the day during which the second server performs read and write operations for the online transaction processing system using the replica of the relational database on the second server;

send a log file associated with the relational database on the first server from the first server directly to the second server to replicate the relational database on the second server following a write operation to the relational database on the first server when the first server performs the read and write operations and the second server performs the read operations during the first portion of the day;

acknowledge the write operation to the relational database on the first server as being successful after receiving a confirmation from the second server that the second server successfully completed replication of the relational database on the second server after receiving the log file;

receive a log file associated with the relational database on the second server directly from the second server to replicate the relational database on the first server following a write operation to the relational database on the second server when the second server performs the read and write operations and the first server performs the read operations during the second portion of the day; and

send a confirmation from the first server to the second server that the first server successfully completed replication of the relational database on the first server after receiving the log file from the second server,

wherein the second server is configured to acknowledge the write operation to the relational database on the second server as being successful after receiving the confirmation from the first server,

wherein a response time for the read and write operations performed by the first server is increased during the first portion of the day; and

wherein a response time for the read and write operations performed by the second server is increased during the second portion of the day.