Patent AU-2018348336-B2 (AU)
Title: Performing a change of primary node in a distributed system
Inventor: LIN PENG
IPC: H04L69/40
Filed: 2018-12-13
Granted: 2020-07-23
Abstract: INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) 
(19) World Intellectual Property 
(1) Organization11111111111111111111111I1111111111111i1111liiiii 
International Bureau (10) International Publication Number 
(43) International Publication Date W O 2019/072296 A2 
18 April 2019 (18.04.2019) W IPO I PCT 
(51) International Patent Classification: HR, HU, ID, IL, IN, IR, IS, JO, JP, KE, KG, KH, KN, KP, 
Not classified KR, KW, KZ, LA, LC, LK, LR, LS, LU, LY, MA, MD, ME, 
(21) International Application Number: MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, 
PCT/CN2018/120873 OM, PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SA, 
SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, 
(22) International Filing Date: TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW.  
13 December 2018 (13.12.2018) (84) Designated States (unless otherwise indicated, for every 
(25) Filing Language: English kind of regional protection available): ARIPO (BW, GH, 
GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, SZ, TZ, 
(26)PublicationLanguage: English UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, TJ, 
(71) Applicant: ALIBABA GROUP HOLDING LIMITED TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, 
[-/CN]; Fourth Floor, One Capital Place, P.O. BOX 847, EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, LV, 
George Town, Grand Cayman (KY). MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, 
TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, 
(72) Inventor: LIN, Peng; Alibaba Group Legal Department 5/ RM,ML, MR, E, SN, TD, TG).  
F, Building3, No.969 West WenYi Road, YuHangDistrict, 
Hangzhou, Zhejiang 311121 (CN). Published: 
(74) Agent: BEIJING BESTIPR INTELLECTUAL PROP- - upon request of the applicant, before the expiration of the 
ERTY LAW CORPORATION; Room 409, Tower B, Ka time limit referred to in Article 2(2)(a) 
Wah Building, No. 9 Shangdi 3rd Street, Haidian District, - without international search report and to be republished 
Beijing 100085 (CN). upon receipt ofthat report (Rule 48.2(g)) 
(81) Designated States (unless otherwise indicated, for every 
kind of national protection available): AE, AG, AL, AM, 
AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, BZ, 
CA, CH, CL, CN, CO, CR, CU, CZ, DE, DJ, DK, DM, DO, 
DZ, EC, EE, EG, ES, Fl, GB, GD, GE, GH, GM, GT, HN, 
(54) Title: PERFORMING A CHANGE OF PRIMARY NODE IN A DISTRIBUTED SYSTEM 
(57) Abstract: A method of performing a change of a primary node 
in a blockchain network includes a backup node of the blockchain net
300 work determining that an epoch change needs to be performed, deter
mining a respective weight of the backup node associated with each of 
three phases of a consensus process in a current epoch, determining a 
weight sum for the backup node based on the respective weights, send
ing an EPOCHCHANGE message to the other network nodes to ap
ply for a new primary node in a new epoch, receiving NEWEPOCH 
messages from the other network nodes, determining whether a num
310 320 330 ber of valid NEWEPOCH messages exceeds a second predetermined 
hal Pasa3 threshold, and determining the backup node to be the new primary node 
sA ECH erure ACCE in the new epoch in response to determining that the number of valid 
messge n sa'- nde messap 
.- NEW EPOCH messages exceeds the second predetermined threshold.  
RFIG.  
o FIG.3