read.py

    if message_type == 'user_read':
        key,_ = data.split('|')

        highest_version = -1
        highest_version_value = ''

        #nodes = random.sample([(hash(key)+i)%N for i in range(R)], Q_r)
        #nodes = random.sample(get_next_live_inc(hash(key), R), Q_r)

        nodes = get_next_live_inc(hash(key), R)
        nodes_replied = 0

        for node in nodes:
            try:
                if node == server_idx:
                    value, version = database[key], database_version[key]
                else:
                    tmp_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                    tmp_sock.connect(server_addresses[node])
                    tmp_sock.sendall(key+'|coordinator_read')
                    data = tmp_sock.recv(1000)
                    value, version, _ = data.split('|')
                    tmp_sock.close()

                nodes_replied += 1
                version = int(version)
                if version > highest_version:
                    highest_version = version
                    highest_version_value = value
            except socket.error:
                continue ,
        
        assert nodes_replied >= Q_r, "Didn't get reply from read quorum, most likely due to multiple failures"

        connection.sendall(highest_version_value+'|user_read_reply')