Methods, systems, and apparatus, including computer programs encoded on computer storage media, for performing view change. One of the methods is to be implemented on a blockchain and performed by a first node of N nodes in a view change protocol. The method includes: multicasting a view change message to at least some of the N nodes; obtaining, respectively from at least Q second nodes of the N nodes, at least Q echo messages each comprising: a consistent current view known to the second node indicating a primary node designated among the N nodes, and a consistent current sequence number known to the second node, the current sequence number associated with a latest transaction or a latest block, the current sequence number is larger than a first sequence number known to the first node; and responsive to obtaining the at least Q echo messages, ending the view change protocol.