US 11,704,290 B2
Methods, devices and systems for maintaining consistency of metadata and data across data centers
Jagane Sundar, Saratoga, CA (US); Michal Dobisek, Prague (CZ); Yeturu Aahlad, Foster City, CA (US); and Mark McKeown, Belfast (IE)
Assigned to WANdisco, Inc., San Ramon, CA (US)
Filed by WANdisco, Inc., San Ramon, CA (US)
Filed on Apr. 28, 2022, as Appl. No. 17/732,300.
Application 17/732,300 is a continuation of application No. 15/457,837, filed on Mar. 13, 2017, granted, now 11,360,942.
Prior Publication US 2023/0012697 A1, Jan. 19, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G06F 16/00 (2019.01); G06F 16/178 (2019.01); G06F 16/13 (2019.01); G06F 16/14 (2019.01); G06F 16/172 (2019.01); G06F 16/182 (2019.01); G06F 16/23 (2019.01)
CPC G06F 16/178 (2019.01) [G06F 16/13 (2019.01); G06F 16/148 (2019.01); G06F 16/172 (2019.01); G06F 16/1844 (2019.01); G06F 16/2365 (2019.01)] 17 Claims
OG exemplary drawing
 
1. A computer-implemented method of maintaining consistency in a distributed file system coupled to a computer network, the method comprising:
receiving a request to create or change a file and, before any data of the file to be created or changed is stored, sequentially:
assigning a unique global sequence number to the creation of or change to the file;
storing, in a first cache memory coupled to a first data replication server in the computer network and in a second cache memory coupled to a second data replication server in the computer network, the assigned unique global sequence number and metadata of the file to be created or changed, such that states of the first and second cache memories are consistent at the unique global sequence number; and
after the first and second cache memories are consistent at the unique global sequence number, enabling data that corresponds to the metadata stored in the first and second cache memories to be written to the file to be created or changed.