Alibaba Group Holding Limited
Online capacity-expanding and online capacity-reducing methods and apparatuses for distributed consensus system

Abstract:

Embodiments of the present disclosure provide a method comprising: adding a second set of one or more servers to a first set of servers of a consensus system to form an expanded set of servers, performing a capacity-expanding operation on one of the second set of one or more servers. The capacity-expanding operation comprises: pausing a service process related to distributed services, updating configuration information of the first set of servers in response to the second set of one or more servers being added, and resuming the service process and initiating master server election for the expanded set of servers, wherein one of the expanded set of servers is elected as a master server, the rest of the expanded set of servers are considered as slave servers. The method can also include performing the capacity-expanding operation sequentially on each of the slave servers, and subsequently, performing the capacity-expanding operation on the master server, and performing the capacity-expanding operation on the second set of one or more servers that have not been subjected to the capacity-expanding operation after completion of the capacity-expanding for the first set of servers.