private void flushV0MsgPackage(BaseSource source, Channel channel,
            ByteBuf binBuffer, String orgAttr) throws Exception {
        if (channel == null || !channel.isWritable()) {
            // release allocated ByteBuf
            binBuffer.release();
            source.fileMetricIncSumStats(StatConstants.EVENT_LINK_UNWRITABLE);
            if (logCounter.shouldPrint()) {
                logger.warn("Send msg but channel full, attr={}, channel={}", orgAttr, channel);
            }
            throw new ChannelUnWritableException("Send response but channel full");
        }
        channel.writeAndFlush(binBuffer);
    }
Build hearbeat(1)-msg response message ByteBuf

@return ByteBuf
inlong-dataproxy/dataproxy-source/src/main/java/org/apache/inlong/dataproxy/source/ServerMessageHandler.java