// if exists, write data body and tag.
if(msg.getRawBodySize() > 0){
if(RpcConstants.EXTRA_DEBUGGING) logger.debug("Writing raw body of size {}", msg.getRawBodySize());
cos.writeRawVarint32(RAW_BODY_TAG);
cos.writeRawVarint32(rawBodyLength);
cos.flush(); // need to flush so that dbody goes after if cos is caching.
CompositeByteBuf cbb = new CompositeByteBuf(buf.alloc(), true, msg.dBodies.length + 1);
cbb.addComponent(buf);