US 11,657,066 B2
Method, apparatus and medium for data synchronization between cloud database nodes
Chong Chen, Richmond Hill (CA); Jin Chen, Richmond Hill (CA); Shu Lin, Richmond Hill (CA); and Chunsheng Sun, Markham (CA)
Assigned to HUAWEI CLOUD COMPUTING TECHNOLOGIES CO., LTD., Gui'an New District (CN)
Filed by HUAWEI CLOUD COMPUTING TECHNOLOGIES CO., LTD., Gui'an New District (CN)
Filed on Nov. 30, 2020, as Appl. No. 17/107,588.
Prior Publication US 2022/0171787 A1, Jun. 2, 2022
Int. Cl. G06F 15/16 (2006.01); G06F 16/27 (2019.01); H04L 67/1095 (2022.01); G06F 16/901 (2019.01); H04L 67/568 (2022.01)
CPC G06F 16/27 (2019.01) [G06F 16/9017 (2019.01); H04L 67/1095 (2013.01); H04L 67/568 (2022.05)] 20 Claims
OG exemplary drawing
 
1. A method for serving database data of a cloud-based database comprising a compute layer and a storage layer, the compute layer comprising a database master server configured to generate redo log records and a database replica server configured to respond to client read requests, the storage layer comprising a log store configured to store the redo log records and a page store configured to store database data pages, update the database data pages based on the redo log records, and provide the updated database data pages to the database replica server, the method comprising:
receiving from a client, at the database replica server, a read request for a desired page of database data; and
in response to receiving the request for the desired page:
in response to determining that neither the database replica server nor the page store currently stores an up to date version of the desired page:
retrieving an out of date stored version of the desired page;
retrieving one or more redo log records associated with the desired page from a log cache operating in the compute layer; and
applying, at the database replica server, the one or more redo log records to the out of date stored version of the desired page to generate an updated desired page; and
sending, from the database replica server to the client, the updated desired page.