Patent ID: 9552173
Date: 2017-01-24
CPC Classifications: G06F

Claim:
1. A data storage system for replicating data from an external server providing a sequence of batches comprising independent write actions, the data storage system comprising: a data storage resource comprising a plurality of data storage volumes; and a plurality of nodes communicatively coupled to each other and to the data storage resource, each node having access to a non-volatile memory and being adapted to receive a write request including a write action belonging to one of said batches and a batch sequence number identifying the position of said batch in said sequence from the external server and to store the write request into its non-volatile memory; the system comprising a further node adapted to act as a coordinator node, said coordinator node being adapted to: receive batch information from the external server indicating the batch sequence number and the number of write actions in said batch; and periodically communicate with the other nodes to determine the highest batch sequence number for which all write actions have been written into the respective non-volatile memories and to communicate a first batch sequence number indicative of the highest batch sequence number to the other nodes; wherein each node is further adapted to: store the communicated first batch sequence number; replicate all write actions belonging to any batch having a sequence number not exceeding the communicated first batch sequence number from its non-volatile memory to a data storage volume in sequential order; and upon completion of the replication, remove the corresponding write request from its non-volatile memory.