Implementations of the present specification include a computer-implemented method for achieving a consensus among a number of network nodes of a blockchain network. The blockchain network includes a primary node and one or more backup nodes. The method includes receiving a transaction request by the primary node, sending a number of first messages to the backup nodes by the primary node, receiving second messages from the backup nodes by the primary node, reconstructing the transaction request based on data in the second messages by the primary node, sending a third message to the backup nodes by the primary node, and executing the transaction request in response to receiving a predetermined number of third messages.